Abstract:
A metalwood coated at least partially with a nanostructure material offer improved performance over existing golf club heads made from a combination of steel and titanium alloys or composite club heads made in part or wholly from fiber-reinforced plastics (FRPs) and metallic sub-components. The components of the metalwood may be coated with variable thicknesses of electro-deposited nanostructure metals and alloys.

Description:
[0001]    The present application claims priority to U.S. Ser. No. 60/891,471, filed Feb. 23, 2007 and U.S. Ser. No. 60/910,781, filed Apr. 9, 2007, the disclosures of which are incorporated herein. 
     
    
     BACKGROUND 
       [0002]    The invention generally relates to metalwood golf clubs including drivers, fairway woods, hybrid irons, irons, wedges, putters and utility clubs. More particularly, this invention relates to the design, manufacturing and construction of metalwood golf club heads, hybrid iron heads, iron heads, wedge heads and putter heads and the components that make the heads, using nanostructured materials in a composite design to improve performance and durability. The invention also relates to golf iron heads having face inserts and in particular to the face inserts having nano crystalline materials as one component of a multi-material component system. 
       BRIEF DESCRIPTION 
       [0003]    Due to the competitive nature of many sports, designers and manufacturers often seek ways to improve the performance of sports equipment by utilizing new advanced materials and construction methods. As can be appreciated, finding a suitable combination of materials and designs to meet a set of performance criteria is a challenging task. 
         [0004]    Drivers have evolved from various materials of construction over the past four centuries. For most of that time, wood, especially a variety known as persimmon was the predominant material of choice for heads of golf clubs known collectively, as “woods” including the driver and fairway woods. In the late 20 th  century, wood was replaced by various metals including steel and titanium alloys allowing the club heads to grow larger at the same weight, thus producing a higher moment of inertia, larger club face and expanded sweet spot all of which improved the launch conditions and accuracy of shots. One particular improvement that relates especially to metal woods is the use of lighter and stronger metals, such as titanium. A significant number of the premium metal woods, especially drivers, are now constructed primarily using titanium. The use of titanium and other lightweight, strong metals has made it possible to create metal woods of ever increasing sizes. The size of metal woods, especially drivers, is often referred to in terms of volume. For instance, current drivers may have a volume of up to 460 cubic centimeters (cc). Oversized metal woods generally provide a larger sweet spot and a higher inertia, which provides greater forgiveness than a golf club having a conventional head size. One advantage derived from the use of lighter and stronger metals is the ability to make thinner walls, including the striking face and all other walls of the metal wood club. This allows designers more leeway in the positioning of weights. For instance, to promote forgiveness, designers may move the weight to the periphery of the metal wood head and backwards from the face. As mentioned above, such weighting generally results in a higher inertia, which results in less twisting due to off-center hits. 
         [0005]    Generally-speaking, the performance of driver heads for game improvement models can be improved by reducing the overall mass of the structure and re-positioning the mass at appropriate locations in the club head to change the launch conditions at impact. A reduced mass in the crown for example, allows the designer to re-position center-of-gravity (c.g.) of the head. One limitation to minimizing the overall head weight is the current strength-to-weight ratio and achievable wall thickness of metals common to club construction including steel and titanium alloys. In general, titanium materials have reached a minimum thickness that can be repeatedly manufactured with high quality and certainty of material properties due to the process limitations of traditional investment casting and forging techniques, and the subsequent heat-treatments required to produce acceptable mechanical properties. Composite construction utilizing various fiber-reinforced materials in the face, crown, skirt and in some cases the entire head, also allowed for forgiving club head designs. At the beginning of the 21 st  century, golf club designers and manufacturers have since continuously experimented with and launched commercially clubs with combinations of metal and fiber-reinforced composite materials to produce clubs with enhanced coefficient of restitution (C.O.R.), reduced stinging vibration, larger moments of inertia (MOI) and unique sounds at impact to differentiate one club from another. This is generally achieved by making the body of the metalwood as light as possible and moving the mass to locations that result in most favorable flight for the golf ball. Various patents have tried to address this issue as indicated below. 
         [0006]    Helmstetter, et al., in U.S. Pat. No. 6,565,452, disclose a multiple material golf club head having a body made from composite materials. 
         [0007]    Beach, et al., in U.S. Pat. Nos. 6,558,271 and 6,991,558, disclose a golf head with skeletal support structure. 
         [0008]    Hocknell, et al., in U.S. Pat. No. 6,471,604, disclose a golf head with a body made of composite material or a thermoplastic material. 
         [0009]    Okumoto, et al., in U.S. Pat. No. 5,193,811, disclose a wood type head body made mainly of synthetic resin and metal sole plate. The metal sole plate has on its surface for bonding with the head body integrally formed members comprising a hosel on the heel side, weights on the toe and rear sides and a beam connecting weights and hosel. 
         [0010]    In U.S. Pat. No. 5,516,107 to Okumoto et al., a golf head with injected foamable material is disclosed. The foamable material expands inside the head cavity to hold the weight members in place. 
         [0011]    Sun, in U.S. Pat. No. 4,872,685, discloses a wood type golf club head wherein a female unit is mated with a male unit to form a unitary golf club head. The female unit comprises of the upper portion of the golf club head and is preferably composed of plastic, alloy or wood. 
         [0012]    Palumbo, et al., in U.S. patent application Ser. No. 11/300,579 entitled “Article Comprising A Fine-Grained Metallic Material And A Polymeric Material” filed on Dec. 15, 2005, disclose a process for at least partially coating a lightweight polymeric material with fine grained metallic material having grain size in the range of 2 nm and 5000 nm; the nano-metal layer having a thickness between 25 μm to 5 cm. 
         [0013]    Other aspects of the present invention relate specifically to the golf clubs called irons. Irons are typically used to strike the golf ball off the ground without the use of a tee. The objective of the shot with irons is to place the golf ball as close to the hole as possible. Landing the golf ball as far as possible is not the primary objective of a shot played with an iron. Since the irons are mostly played off the ground or the turf, interaction of the iron with the turf plays a significant role in determining the final location of the golf ball. Additionally, the golf ball may not always rest on a perfectly flat plane resulting in what is termed as an uphill or a downhill lie. The purpose of making an iron golf club head with a face insert is primarily to reduce the weight in the face and move that weight to the perimeter of the iron head so as to increase the moment of inertia of the head. Making a head with higher moment-of-inertia allows a player to mis-hit the ball and still end up with a favorable result. This is described as making the club more forgiving. Thus it is desired by a player to have very forgiving irons, so that the differences in lies and mis-hits result in a favorable location of the golf ball for the next shot. Use of multi-materials in golf iron club heads have allowed the heads to be more forgiving. 
         [0014]    Anderson, in U.S. Pat. Nos. 5,024,437, 5,094,383, 5,255,918, 5,261,663 and 5,261,664, has disclosed a club head body made from cast metal material while the face insert was made from hot forged metal material. 
         [0015]    Viste, in U.S. Pat. No. 5,282,624, discloses a club head made from cast metal body and forged steel face insert with grooves on the exterior surface and the interior surface of the face insert and having a thickness of 3 mm. 
         [0016]    Rogers, in U.S. Pat. No. 3,970,236, discloses an iron club head with a formed metal face plate insert fusion bonded to a cast iron body. 
         [0017]    Okumoto, in U.S. Pat. No. 5,228,694, discloses an iron club head having a stainless steel sole and hosel, a core made from a bulk molding compound or the like, a weight composed of a tungsten and polyamide resin, and an outer-shell made of a fiber-reinforced resin. 
         [0018]    Nagasaki et. al., disclose, in U.S. Pat. Nos. 4,792,139, 4,798,383, 4,792,139 an 4,884,812, a golf iron club having a stainless steel head with a fiber reinforced plastic back plate to allow for weight adjustment and ideal inertia moment adjustment. 
         [0019]    Fujimura, in U.S. Pat. No. 4,848,747, discloses a metal iron club head with a carbon fiber reinforced plastic back plate to increase the sweet spot. A ring is used to fix the position of the back plate. 
         [0020]    Nakanishi, et. al., in U.S. Pat. Nos. 4,928,972 and 4,964,640, disclose an stainless steel iron club head with a fiber reinforcement in a rear recess to provide a dampening means for shock and vibrations, a means for increasing the inertial moment, a means for adjusting the center of gravity and a means for reinforcing the back plate. 
         [0021]    Take, in U.S. Pat. No. 5,190,290, discloses an iron club head with a metal body, a filling member composed of a light weight material such as a plastic, and a fiber-reinforced resin molded on the metal body and the filling member. 
         [0022]    Oku, in U.S. Pat. No. 5,411,264, discloses a metal body with a backwardly extended flange and an elastic fiber face plate in order to increase the moment of inertia and minimize head vibrations. 
         [0023]    Aizawa, in U.S. Pat. No. 5,472,201, discloses an iron club head with a body made from stainless steel, a face member composed of a fiber reinforced resin and protective layer composed of a metal, in order to provide a deep center of gravity and reduce shocks. 
         [0024]    Meyer, in U.S. Pat. No. 5,326,106, discloses an iron golf club head with a metal blade portion and hosel composed of a lightweight material such as a fiber reinforced resin. 
         [0025]    Aizawa, in U.S. Pat. No. 4,664,383, to discloses a metal core covered with multiple layers of a reinforced synthetic resin club head to provide greater ball hitting distance. 
         [0026]    Yoneyama, in U.S. Pat. No. 4,667,963, discloses an iron golf club head with a metal sole and a filling member composed of a fiber reinforced resins material in order to provide greater hitting distance. 
         [0027]    The earliest patents for making nano crystalline metals using electrodeposition processes are U.S. Pat. No. 5,352,266 and U.S. Pat. No. 5,433,797 to Erb et al. These patents discloses a process for producing nano crystalline nickel iron alloy having a grain size of less than 11 nanometers. 
         [0028]    Schulz et. al., in U.S. Pat. No. 6,051,046 and U.S. Pat. No. 6,277,170, disclose nano crystalline nickel based alloys having grain size less than 100 nanometers. 
         [0029]    Hui, in U.S. Pat. No. 6,200,450, discloses a method for electrodepositing a nickel-iron-tungsten phosphorous alloy to promote wear resistance. 
         [0030]    Taylor et. al., in U.S. Pat. No. 6,080,504, disclose a method for forming nano crystalline metals on a substrate. 
         [0031]    Gonsalves, in U.S. Pat. No. 5,589,011, disclose a steel powder having a grain size in the nanometer range, specifically in the 50 nanometer size, and the steel powder is an alloy composed of iron, chromium, molybdenum, vanadium and carbon. 
         [0032]    Gonsalves, in U.S. Pat. No. 5,984,996, discloses nanostructured steel, aluminum, aluminum oxide, aluminum nitride, and other metals having crystallite size ranging from 45 nanometers to 75 nanometers. 
         [0033]    Gonsalves, in U.S. Pat. No. 6,033,624, discloses a chemical synthesis method for producing nanostructured metals, metal carbides and metal alloys. 
         [0034]    Ezaki et. al., in U.S. Pat. No. 5,603,667, disclose an iron with nickel plated copper or a copper alloy striking face. 
         [0035]    Saeki, in U.S. Pat. No. 5,207,427, discloses an iron with a non-electrolytic nickel-boron plating and a chromate film, and a method for manufacturing such an iron. 
         [0036]    Nagamoto, in U.S. Pat. No. 5,792,004, discloses an iron composed of a soft-iron material with a carbonized surface layer. 
         [0037]    Harada et al., in U.S. Pat. No. 5,131,986, disclose a method for manufacturing a golf club head by electrolytic deposition of nickel based alloys. 
         [0038]    Sasamoto et al. in U.S. Pat. No. 6,193,614, discloses as golf club head with a face portion that is arranged to have its crystal grains of the material of the face portion oriented in a vertical direction. This patent also discloses nickel-plating of the face portion. 
         [0039]    Buettner, in U.S. Pat. No. 5,531,444, discloses a wear resistant titanium nitride coated iron composed of a ferrous material. 
         [0040]    Winrow et al., in U.S. Pat. No. 5,851,158, disclose a golf club head with a coating formed by a high velocity thermal spray process. 
         [0041]    Byrne et al., in U.S. Pat. No. 7,087,268, discloses a method of plating a golf club head composed of magnesium, magnesium alloys, aluminum, or aluminum alloys. 
         [0042]    Reyes et al., in U.S. Pat. No. 7,063,628, disclose a golf club head having a magnesium portion that is plated with a nickel or nickel alloy based material. 
         [0043]    Deshmukh, in U.S. Pat. Nos. 7,214,143 and 7,318,781, discloses face inserts with nano-crystalline metals, where the nano-crystalline metals were deposited on metallic and non-metallic substrates without an intermediate layer. 
         [0044]    Palumbo et al., in U.S. Patent Publication 2006/0135281, disclose golf shafts or golf club heads including face plates that are plated with course-grained or fine-grained metallic materials. 
         [0045]    Hocknell et al., in U.S. Patent Publication 2007/0293348, disclose a nanocrystalline face insert where the nanocrystalline layer is disposed on the substrate without any activation of the substrate. 
         [0046]    While these and other patents attempt to address some of the deficiencies of the current metalwoods and face inserts, there is a need for use of a nanostructured material in the composition of a metalwood and face insert to overcome these deficiencies. 
       SUMMARY OF THE INVENTION 
       [0047]    Manufacturers and designers who have used carbon-fiber reinforced plastics, commonly known as “carbon composites” for the crown or body of metalwoods have since explored the concept of using just thermoplastic or thermoset polymers without fiber reinforcement, due to their low density and moldability into complex shapes at a relatively low cost. However, the structural strength, fatigue life and maximum deflection limits of these plastic crowns have not been within acceptable performance and durability limits. In particular, the strength of neat plastics alone does not allow for the replacement of the thin-walled titanium and steel crowns common to many designs available on the market today. However, by adding a thin structural layer of nanostructured metal onto the surface of certain polymers in a metalwood crown or body design, or fully encapsulating these polymers, the resulting density of the nanostructured metal+polymer composite structure can be reduced from 4.5 g/cc for titanium alloys to less than 1.5 g/cc. This allows for the designer to shift center-of-gravity (c.g.) down toward the sole and back, improving the MOI and even COR characteristics of the entire head. These new mass properties and flex characteristics have positive effects on the performance, sound, and durability of metalwoods for the golfer. 
         [0048]    Driver heads made with fiber-reinforced or neat resin polymer crowns, skirts, and bodies, also suffer from a low or poor-dampening response after impact with the golf ball, thus producing a less pronounced sound at impact which is less pleasing to the golfer. Low modulus polymers and/or thermoset polymer systems can reduce the performance of a club due to energy loss in the system at impact with golf ball. Titanium and steel metalwoods with their larger cavities and thinner walls produce a different and often times louder or higher-pitched sound at impact that many golfers prefer. By combining a polymer substrate with a nanostructured metal, the overall strength, strength-to weight, and sound at impact of metalwoods are improved. 
         [0049]    In one aspect, the invention relates to a variety of golf club heads including drivers, fairway woods, hybrid and utility clubs, herein called “metalwoods.” The metalwoods with nanostructured metals fused to polymers can be any designed for a variety of players with different skill levels from the beginner to the amateur and even the professional. 
         [0050]    In one embodiment, the metalwoods include a portion that includes a nanostructured material. The nanostructured material includes a metal, and the nanostructured material has an average grain size that is in the range of 2 nm to 100 nm, a yield strength that is in the range of 600 MegaPascal (“MPa”) to 2,750 MPa, and a hardness that is in the range of 460 Vickers to 2,000 Vickers. 
         [0051]    In another embodiment, the metalwoods include an electro-deposited or electro-formed fine-grained metal or metal alloy coating having a thickness between 10 micrometers (“μm”) and 5 millimeters (“mm”). The coating exhibits resilience of at least 0.25 MPa and up to 25 MPa, and an elastic strain limit of at least 0.75% and up to 2.00%. 
         [0052]    In another embodiment, the metalwoods include a neat resin of thermoplastic or thermoset polymer material as the crown, skirt, or body component or the like incorporating a metallic coating representing at least 0.5%, such as more than 10% or more than 20%, and up to 75%, 85%, or 95% of a total weight on a polymer substrate optionally containing graphite/carbon or other fibers including chopped fiber or other strength-enhancing particulates. A lateral or bending stiffness per unit weight of the metalwoods containing the metallic coating is improved by at least about 5% when compared to a lateral or bending stiffness of a similar metalwood crown, skirt or body component not containing the metallic coating or encapsulation. 
         [0053]    In another embodiment, the metalwoods include a graphite fiber-reinforced composite crown, skirt, or body component or the like incorporating a metallic coating representing at least 0.5%, such as more than 10% or more than 20%, and up to 75%, 85%, or 95% of a total weight on a polymer substrate optionally containing graphite/carbon or other fibers including chopped fiber or other strength-enhancing particulates. A lateral or bending stiffness per unit weight of the metalwood containing the metallic coating is improved by at least about 5% when compared to a lateral or bending stiffness of a similar metalwood crown, skirt or body component not containing the metallic coating or encapsulation. 
         [0054]    In another embodiment, the metalwood includes a portion that includes a first layer and a second layer adjacent to the first layer. At least one of the first layer and the second layer includes a nanostructured material that has a grain size in the submicron range, such as in the nanometer range. Nanostructured materials can be formed as outlined in the patent application of Palumbo et al., U.S. patent application Ser. No. 11/305,842, entitled “Sports Article Formed Using Nanostructured Materials” and filed on Dec. 9, 2004, and the patent application of Palumbo et al., U.S. patent application Ser. No. 10/516,300, entitled “Process for Electro-plating Metallic and Metal Matrix Composite Foils, Coatings and Microcomponents” and filed on Dec. 9, 2004, the disclosures of which are incorporated herein by reference in their entirety. 
         [0055]    An improved process can be employed to create high strength, equiaxed coatings on metallic components or on non-conductive components that have been metallized to render them suitable for electro-plating. In an alternative embodiment, the process can be used to electro-form a stand-alone article on a mandrel or other suitable substrate and, after reaching a desired plating thickness, to remove the free-standing electro-formed article from the temporary substrate. 
         [0056]    In another aspect, the invention relates to an improved process for producing metalwoods. In one embodiment, the process includes: (a) positioning a metallic or metallized work piece or a reusable mandrel/temporary substrate to be plated in a plating tank containing a suitable electrolyte; (b) providing electrical connections to the work piece and to one or several anodes; and (c) forming and electrodepositing a metallic material with an average grain size of less than 100 nanometers (nm) on at least part of the surface of the work piece using a suitable DC electro-deposition process. 
         [0057]    In the process of an embodiment of the invention, an electro-deposited metallic coating optionally contains at least 2.5% by volume particulate, such as at least 5%, and up to 75% by volume particulate. The particulate can be selected from the group of metal powders, metal alloy powders, and metal oxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn, V, and Zn; nitrides of Al, B and Si; carbides of B, Cr, Si, Ti, V, Zr, Mo, Cr, Fe, Ni, Co, Nb, W, Hf and Ta; borides of Ti, V, Zr, W, Hf, Ta, Si, Mo, Nb, Cr, and Fe; MoS 2 ; and organic materials such as PTFE and other polymeric materials. The particulate average particle size is typically below 10,000 nm (or 10 μm), such as below 5,000 nm (or 5 μm), below 1,000 nm (or 1 μm), or below 500 nm. 
         [0058]    An embodiment of the invention provides for electro-deposited fine-grained layers, having a thickness of at least 0.030 mm, such as more than 0.05 mm or more than 0.1 mm, on surfaces of appropriate articles, including entire golf club heads, face inserts for golf club heads, crowns of golf club heads, skirts of golf club heads, bodies of golf club heads, sole plates of golf club heads, and suitable sub-components thereof. 
         [0059]    According to an embodiment of the invention, patches or sections of nanostructured materials can be formed on selected areas, such as on golf crowns, bodies, skirts, soles or sections of metalwood head without the need to coat an entire article. 
         [0060]    According to an embodiment of the invention, patches, sleeves or structural shells of nanostructured materials, which need not be uniform in thickness, can be electro-deposited in order to form a thicker structural shell on selected sections or sections particularly prone to heavy use or impact, such as the crown of a metalwood; along the skirt or middle section of a metalwood where it may bang against the ground during play, other clubs in the bag, or even be damaged during transport; and/or on sole of a metalwood body that may be subject to impact forces that might otherwise produce scratches, denting and the like. 
         [0061]    In one embodiment a metallic alloy core or substrate in lieu of a polymer substrate may be completely encapsulated by nano-structured material including nanocrystalline metals. The encapsulation increases the stiffness of the structure, and prevents the possibility of corrosion of the metallic alloy substrate. 
         [0062]    In some embodiments the metallic alloy core or substrate need not be encapsulated symmetrically. The location of the substrate can be chosen depending on the particular application. The encapsulation along the perimeter can be controlled during the deposition process or could be later machined to the design requirement. In some exemplary embodiments the encapsulation can vary from 0 to 1.0 mm. 
         [0063]    In some embodiments metalwood may be coated with a nanostructured material to improve performance. 
         [0064]    In some embodiments, metalwood, including drivers, fairway woods, hybrid and utility clubs may be coated in whole or part with a nanostructured material. In one exemplary embodiment a nanostructured material may be applied to approximately the entire surface of the crown, to improve the deflection at impact allowing for a higher C.O.R. of the metalwood head structure and durability of the crown in particular after repeated golf ball impacts where the load is transferred to the crown at the joint interface. 
         [0065]    In another exemplary embodiment a nanostructured material may completely encapsulate a polymer crown, allowing for improved performance, durability and sound at weight similar to steel or titanium crowns. 
         [0066]    In yet another exemplary embodiment a nanostructured material may be applied to the crown and skirt elements of a metalwood body either fully encapsulating or partially, to improve the mechanical stiffness, overall durability, sound production and vibrational feel of the metalwood head during impact with golf balls. 
         [0067]    Other aspects and embodiments of the invention are also contemplated. For example, another aspect of the invention relates to a method of forming metalwood components including crowns, skirts, sole plates, body elements, shaft hosels, and striking faces including a nanostructured material coating with a substrate or as a free-standing electro-formed article that can be subsequently joined using traditional or novel methods. 
         [0068]    The foregoing summary and the following detailed description are not meant to restrict the invention to any particular embodiment, but are merely meant to describe some embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0069]      FIG. 1  is a cross-sectional schematic view of a portion of a sports article, such as a portion of a metalwood, according to an embodiment of the invention, with nanostructured material providing a structural shell or coating. 
           [0070]      FIG. 2  is a cross-sectional schematic view of a portion of a sports article, such as a portion of a metalwood, according to another embodiment of the invention, with a nanostructured material over a substrate in a sandwich construction. 
           [0071]      FIG. 3  is a cross-sectional schematic view of a portion of a sports article, such as a portion of a metalwood, according to yet another embodiment of the invention, with a nanostructured material in a sandwich construction with a variable thickness laminate. 
           [0072]      FIG. 4  is a cross-sectional schematic view of a portion of a sports article, such as a portion of a metalwood, according to yet another embodiment of the invention, with a nanostructured material and a substrate of variable thickness. 
           [0073]      FIG. 5  is a cross-sectional schematic view of a portion of a sports article, such as a portion of a metalwood, according to yet another embodiment of the invention with a nanostructured material in a sandwich construction and a substrate of variable thickness. 
           [0074]      FIG. 6  is a cross-sectional schematic view of a portion of a sports article, such as a portion of a metalwood, according to yet another embodiment of the invention, with a nanostructured material in a sandwich construction with different nanostructured materials and a substrate of variable thickness. 
           [0075]      FIG. 7  is a cross-sectional schematic view of a portion of a sports article, such as a portion of a metalwood, according to yet another embodiment of the invention, with nanostructured materials fully encapsulating a substrate of variable thickness. 
           [0076]      FIG. 8  is an exploded schematic view of a metalwood golf club. 
           [0077]      FIG. 9  is a front elevational view of a face of the metalwood golf club head of  FIG. 8  having electro-deposited nanostructured material along different sections thereof. 
           [0078]      FIG. 10  is a side elevational view of the face of  FIG. 8 . 
           [0079]      FIG. 11  is an orthotropic projection exploded schematic view of the metalwood of  FIG. 8 . 
           [0080]      FIG. 12  is cross-sectional schematic view of a metalwood lap joint with deposited nanostructured material adhered to a face. 
           [0081]      FIG. 13  is a cross-sectional schematic view of a metalwood trap joint with deposited nanostructured material adhered to a face. 
           [0082]      FIG. 14  is a cross-sectional schematic view of a metalwood with deposited nanostructured material adhered to a face and having a combination trap joint with a crown and a lap joint with a sole plate. 
           [0083]      FIG. 15  illustrates a metalwood crown with deposited nanostructured material. 
           [0084]      FIG. 16  illustrates assembled golf clubs with deposited nanostructured material. 
         FIG.  17  illustrates an gold club iron insert with deposited nanostructured material. 
         [0085]      FIG. 18  illustrates the insert of  FIG. 17  secured to a head of a golf club iron. 
           [0086]      FIG. 19  illustrated a head of a golf club iron with deposited nanostructured material. 
           [0087]      FIG. 20  illustrated a head of a metalwood with deposited nanostructured material. 
       
    
    
     DETAILED DESCRIPTION 
       [0088]    Overview 
         [0089]    The present invention generally relates to golf club head design and construction. Metalwoods in accordance with various embodiments of the invention can be formed with a variety of polymer or metallic substrates fused with nanostructured materials having desirable mechanical and vibro-acoustic properties. In particular, the nanostructured materials can exhibit characteristics such as high yield strength, high strength-to-weight ratio, high resilience, high fracture toughness, high elasticity, low or high vibration-damping, high hardness, high ductility, high wear resistance, high corrosion resistance. In such a manner, the metalwoods can have improved performance characteristics while being formed in a cost-effective manner. Examples of the metalwood heads in this invention include drivers, fairway woods, hybrid and utility golf clubs. 
         [0090]    Definitions 
         [0091]    The following definitions apply to some of the features described with respect to some embodiments of the invention. These definitions may likewise be expanded upon herein. 
         [0092]    As used herein, the singular terms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to an object can include multiple objects unless the context clearly dictates otherwise. 
         [0093]    As used herein, the term “set” refers to a collection of one or more items. Thus, for example, a set of objects can include a single object or multiple objects. Items included in a set can also be referred to as members of the set. Items included in a set can be the same or different. In some instances, items included in a set can share one or more common characteristics. 
         [0094]    As used herein, the term “adjacent” refers to being near or adjoining. Objects that are adjacent can be spaced apart from one another or can be in actual or direct contact with one another. In some instances, objects that are adjacent can be coupled to one another or can be formed integrally with one another. 
         [0095]    As used herein, the terms “integral” and “integrally” refer to a non-discrete portion of an object. Thus, for example, a golf club head including a skirt that is formed integrally with the sole plate portion can refer to an implementation of the golf club head in which the skirt portion and the sole portion are formed as a monolithic unit. An integrally formed portion of an object can differ from one that is coupled to the object, since the integrally formed portion of the object typically does not form an interface with a remaining portion of the object. 
         [0096]    As used herein, the term “submicron range” refers to a range of dimensions less than about 1,000 nm, such as from about 2 nm to about 900 nm, from about 2 nm to about 750 nm, from about 2 nm to about 500 nm, from about 2 nm to about 300 nm, from about 2 nm to about 100 nm, from about 10 nm to about 50 nm, or from about 10 nm to about 25 nm. 
         [0097]    As used herein, the term “nanometer range” or “nm range” refers to a range of dimensions from about 1 nm to about 100 nm, such as from about 2 nm to about 100 nm, from about 10 nm to about 50 nm, or from about 10 nm to about 25 nm. 
         [0098]    As used herein, the term “size” refers to a characteristic dimension of an object. Thus, for example, a size of an object that is a spherical can refer to a diameter of the object. In the case of an object that is non-spherical, a size of the object can refer to an average of various dimensions of the object. Thus, for example, a size of an object that is a spheroidal can refer to an average of a major axis and a minor axis of the object. When referring to a set of objects as having a specific size, it is contemplated that the objects can have a distribution of sizes around the specific size. Thus, as used herein, a size of a set of objects can refer to a typical size of a distribution of sizes, such as an average size, a median size, or a peak size. 
         [0099]    As used herein, the term “grain size” refers to a size of a set of constituents or components included in a material, such as a nanostructured material. When referring to a material as being “fine-grained,” it is contemplated that the material can have an average grain size in the submicron range, such as in the nm range. 
         [0100]    As used herein, the term “microstructure” refers to a microscopic configuration of a material. An example of a microstructure is one that is quasi-isotropic in which a set of crystals are relatively uniform in shape and size and exhibit a relatively uniform grain boundary orientation. Another example of a microstructure is one that is anisotropic in which a set of crystals exhibit relatively large deviations in terms of shape, size, grain boundary orientation, texture, or a combination thereof. 
         [0101]    As used herein, the term “metalwood” refers to a range of golf club heads known as the driver, fairway wood, hybrid iron, hybrid club, hybrid wood, utility club, utility iron, iron-wood, and other specific names and embodiments used by the golf industry and golfing consumers to describe club heads meant to be attached to a shaft and used to play the game of golf. Alternatively, “metalwood” also refers to portions of a golf club head including the face, hosel, crown, skirt, soleplate or body, collectively known as a golf cub head. 
         [0102]    As used herein the term “golf iron” refers to a range of golf club heads known irons, long irons, short irons, wedges, lob wedges, approach wedges and other specific names and embodiments used by the golf industry and golfing consumers to describe club heads meant to be attached to a shaft and used to play the game of golf. Alternatively, “golf iron” also refers to portions of a golf club head including the face insert, the body cavity, hosel, collectively known as a golf club head. 
         [0103]    Nanostructured Materials 
         [0104]    Certain embodiments of the invention relate to nanostructured materials that can be used for metalwood golf club heads. A microstructure and resulting characteristics of nanostructured materials can be engineered to meet performance criteria for a variety of metalwoods. In some instances, engineering of nanostructured materials can involve enhancing or optimizing a set of characteristics, such as strength, strength-to-weight ratio, resilience, fracture toughness, vibration damping, hardness, ductility, and wear resistance. In other instances, engineering of nanostructured materials can involve trade-offs between different characteristics. 
         [0105]    According to some embodiments of the invention, a nanostructured material has a relatively high density of grain boundaries as compared with other types of materials. This high density of grain boundaries can translate into a relatively large percentage of atoms that are adjacent to grain boundaries. In some instances, up to about 50 percent or more of the atoms can be adjacent to grain boundaries. Without wishing to be bound by a particular theory, it is believed that this high density of grain boundaries promotes a number of desirable characteristics in accordance with the Hall-Petch Effect. In order to achieve this high density of grain boundaries, the nanostructured material is typically formed with a relatively small grain size. Thus, for example, the nanostructured material can be formed with a grain size in the submicron range, such as in the nm range. As the grain size is reduced, a number of characteristics of the nanostructured material can be enhanced. For example, in the case of nickel, its hardness can increase from about 140 Vickers for a grain size greater than about 5 μm to about 300 Vickers for a grain size of about 100 nm and ultimately to about 600 Vickers for a grain size of about 10 nm. Similarly, ultimate tensile strength of nickel can increase from about 400 MPa for a grain size greater than about 5 μm to 670 MPa for a grain size of about 100 nm and ultimately to over 900 MPa for a grain size of about 10 nm. 
         [0106]    According to some embodiments of the invention, a nanostructured material includes a set of crystals that have a size in the nm range and, thus, can be referred to as a nanocrystalline material. However, as described herein, nanostructured materials having desirable characteristics can also be formed with larger grain sizes, such as in the submicron range. A microstructure of the nanostructured material can be engineered to cover a wide range of microstructure types, including one that is quasi-isotropic, one that is slightly-anisotropic, and one that is anisotropic and highly textured. Within this range of microstructure types, a reduction in size of the set of crystals can be used to promote a number of desirable characteristics. 
         [0107]    Particularly useful nanostructured materials include those that exhibit a set of desirable characteristics, such as high strength, high strength-to-weight ratio, high resilience (e.g., defined as R=σ 2 /2E), high fracture toughness, high elasticity, high vibration damping, high hardness, high ductility, high wear resistance, and low friction. For example, in terms of strength, particularly useful nanostructured materials include those having a yield strength that is at least about 600 MPa, at least about 1,000 MPa, or at least about 1,500 MPa, and up to about 2,750 MPa, such as up to about 2,500 MPa. In terms of resilience, particularly useful nanostructured materials include those having a modulus of resilience that is at least about 0.15 MPa, such as at least about 1 MPa, at least about 2 MPa, at least about 5 MPa, or at least about 7 MPa, and up to about 25 MPa, such as up to about 12 MPa. In terms of elasticity, particularly useful nanostructured materials include those having an elastic limit that is at least about 0.75 percent, such as at least about 1 percent or at least about 1.5 percent, and up to about 2 percent. In terms of hardness, particularly useful nanostructured materials include those having a hardness that is at least about 300 Vickers, at least about 400 Vickers, or at least about 500 Vickers, and up to about 2,000 Vickers, such as up to about 1,000 Vickers, up to about 800 Vickers, or up to about 600 Vickers. In terms of ductility, particularly useful nanostructured materials include those having a tensile strain-to-failure that is at least about 1 percent, such as at least about 3 percent or at least about 5 percent, and up to about 15 percent, such as up to about 10 percent or up to about 7 percent. 
         [0108]    Nanostructured materials can be formed as outlined in the patent application of Palumbo et al., U.S. patent application Ser. No. 11/013,456, entitled “Strong, Lightweight Article Containing a Fine-Grained Metallic Layer” and filed on Dec. 17, 2004, and the patent application of Palumbo et al., U.S. patent application Ser. No. 10/516,300, entitled “Process for Electro-plating Metallic and Metal Matrix Composite Foils, Coatings and Microcomponents” and filed on Dec. 9, 2004, the disclosures of which are incorporated herein by reference in their entirety. 
         [0109]    In some instances, a nanostructured material can be formed as a metal matrix composite in which a metal or a metal alloy forms a matrix within which a set of additives are dispersed. A variety of additives can be used, and the selection of a specific additive can be dependent upon a variety of considerations, such as its ability to facilitate formation of the nanostructured material and its ability to enhance characteristics of the nanostructured material. Particularly useful additives include particulate additives formed of: (1) metals selected from the group of Al, Co, Cu, In, Mg, Ni, Sn, V, and Zn; (2) metal alloys formed of these metals; (3) metal oxides formed of these metals; (4) nitrides of Al, B, and Si; (5) C, such as in the form of graphite, diamond, nanotubes, and Buckminster Fullerenes; (6) carbides of B, Cr, Si, Ti, V, Zr, Mo, Cr, Ni, Co, Nb, Ta, Hf and W; borides of Ti, V, Zr, W, Si, Mo, Nb, Cr, and Fe; (7) self-lubricating materials, such as MoS 2 ; and (8) polymers, such as polytetrafluoroethylene (“PTFE”). During formation of a nanostructured material, a set of particulate additives can be added in the form of powders, fibers, or flakes that have a size in the submicron range, such as in the nm range. Depending on specific characteristics that are desired, the resulting nanostructured material can include an amount of particulate additives that is at least about 2.5 percent by volume, such as at least about 5 percent by volume, and up to about 75 percent by volume. 
         [0110]    Table 1 below provides examples of classes of nanostructured materials that can be used to form metalwoods described herein. 
         [0000]    
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Nanostructured Materials 
                 Characteristics 
               
               
                   
               
             
             
               
                 n-Ni, n-Ni Fe, n-Co P 
                 high strength, high fracture toughness, high 
               
               
                   
                 degree of hardness and wear resistance 
               
               
                   
               
             
          
         
       
     
         [0111]    The foregoing provides a general overview of some embodiments of the invention. 
         [0112]    Metalwoods—Implementations of Metalwoods 
         [0113]    With reference to  FIG. 1 , a cross-sectional schematic view of a portion  100  of a sports article, such as a metalwood, according to an embodiment of the invention, is illustrated. The portion  100  is implemented in accordance with a multi-layered design and includes a first layer  102  and a second layer  104  that is adjacent to the first layer  102 . The second layer  104  can be formed adjacent to the first layer  102  via electro-deposition. However, it is contemplated that the second layer  104  can be formed using any other suitable manufacturing technique. 
         [0114]    The first layer  102  is implemented as a substrate and is formed of any suitable material, such as a fibrous material, a foam, a ceramic, a metal, a metal alloy, a polymer, or a composite. Thus, for example, the first layer  102  can be formed of wood; an aluminum alloy, such as a 6000-series aluminum alloy or a 7000-series aluminum alloy; a steel alloy; a thermoplastic or thermoset polymer, polyetherimide (PEI), a copolymer of acrylonitrile, butadiene, and styrene (ABS); a fiber-reinforced epoxy composite (FRP), such as a graphite fiber/epoxy composite (CFRP); a fiberglass/epoxy composite (GFRP); a poly-paraphenylene terephthalamide fiber/epoxy composite, such as a Kevlar® brand fiber/epoxy composite, where Kevlar brand fibers are available from E.I. du Pont &amp; Nemours, Inc., Wilmington, Del.; or Nylon® or Zytel® or Minion® families of polymers such as available from du Pont, Inc., or a polyethylene fiber/epoxy composite, such as a Spectra® brand fiber/epoxy composite, where Spectra brand fibers are available from Honeywell International Inc., Morristown, N.J. The selection of a material forming the first layer  102  can be dependent upon a variety of considerations, such as its ability to facilitate formation of the second layer  104 , its ability to be molded or shaped into a desired form, and desired characteristics of the portion  100 . 
         [0115]    While not illustrated in  FIG. 1 , it is contemplated that the first layer  102  can be formed so as to include two or more sub-layers, which can be formed of the same material or different materials. For certain implementations, at least one of the sub-layers can be formed of a conductive material, such as in the form of a coating of a metal. As can be appreciated, such implementation of the first layer  102  can be referred to as a “metallized” form of the first layer  102 . The conductive material can be deposited using any suitable manufacturing technique, such as metallization in an organic or inorganic bath, aerosol spraying, electro-less deposition, chemical vapor deposition, physical vapor deposition, or any other suitable coating or printing technique. Such metallized form can be desirable, since the conductive material can facilitate formation of the second layer  104  as well as provide enhanced durability and strength to the portion  100 . 
         [0116]    The second layer  104  is implemented as a coating and is formed of a nanostructured material. Thus, for example, the second layer  104  can be formed of n-Ni, n-Ni Fe, n-Co P. The selection of the nanostructured material can be dependent upon a variety of considerations, such as desired characteristics of the portion  100 . 
         [0117]    During use, the second layer  104  can be positioned so that it is exposed to an outside environment, thus serving as an outer-coating. It is also contemplated that the second layer  104  can be positioned so that it is adjacent to an internal compartment, thus serving as an inner-coating. Referring to  FIG. 1 , in some embodiments the second layer  104  at least partly covers a surface  106  of the first layer  102 . Depending on characteristics of the first layer  102  or a specific manufacturing technique used, the second layer  104  can extend below the surface  106  and at least partly permeate the first layer  102 . While two layers are illustrated in  FIG. 1 , it is contemplated that the portion  100  can include more or less layers for other implementations. In particular, it is contemplated that the portion  100  can include a third layer (not illustrated in  FIG. 1 ) that is formed of the same or a different nanostructured material. It is also contemplated that the portion  100  can be implemented in accordance with an electro-formed design, such that the first layer  102  serves as a temporary substrate during formation of the second layer  104 . Subsequent to the formation of the second layer  104 , the first layer  102  can be separated using any suitable manufacturing technique. 
         [0118]    Depending upon specific characteristics desired for the portion  100 , the second layer  104  can cover from about 1 to about 100 percent of the surface  106  of the first layer  102 . Thus, for example, the second layer  104  can cover from about 20 to about 100 percent, from about 50 to about 100 percent, or from about 80 to about 100 percent of the surface  106 . When mechanical characteristics of the portion  100  are a controlling consideration, the second layer  104  can cover a larger percentage of the surface  106 . On the other hand, when other characteristics of the portion  100  are a controlling consideration, the second layer  104  can cover a smaller percentage of the surface  106 . Alternatively, or in conjunction, when balancing mechanical and other characteristics of the portion  100 , it can be desirable to adjust a thickness of the second layer  104 . 
         [0119]    Layer thicknesses may vary. In some embodiments, the second layer  104  can have a thickness can have a thickness that is in the range from about 10 μm to about 5 mm. Thus, for example, the second layer  104  can have a thickness that is at least about 10 μm, such as at least about 25 μm or at least about 30 μm, and up to about 5 mm, such as up to about 400 μm or up to about 100 μm. 
         [0120]    When mechanical characteristics of the portion  100  are a controlling consideration, the second layer  104  can have a greater thickness or a larger thickness to grain size ratio. On the other hand, when other characteristics of the portion  100  are a controlling consideration, the second layer  104  can have a smaller thickness or a smaller thickness to grain size ratio. Alternatively, or in conjunction, when balancing mechanical and other characteristics of the portion  100 , it can be desirable to adjust a percentage of the surface  106  that is covered by the second layer  104 . 
         [0121]    For certain implementations, the second layer  104  can represent from about 1 to about 100 percent of a total weight of the portion  100 . Thus, for example, the second layer  104  can represent at least about 5 percent of the total weight, such as at least about 10 percent or at least about 20 percent, and up to about 95 percent of the total weight, such as up to about 85 percent or up to about 75 percent. When mechanical characteristics of the portion  100  are a controlling consideration, the second layer  104  can represent a larger weight percentage of the portion  100 . On the other hand, when other characteristics of the portion  100  are a controlling consideration, the second layer  104  can represent a lower weight percentage of the portion  100 . Alternatively, or in conjunction, when balancing mechanical and other characteristics of the portion  100 , it can be desirable to adjust a thickness of the second layer  104  or a percentage of the surface  106  that is covered by the second layer  104 . 
         [0122]    In some instances, the second layer  104  can be formed so as to provide substantially uniform characteristics across the surface  106  of the first layer  102 . Thus, as illustrated in  FIG. 1 , the nanostructured material is substantially uniformly distributed across the surface  106 . Such uniformity in distribution can serve to reduce or prevent the occurrence of a weak spot at or near a section of the portion  100  that includes a lesser amount of the nanostructured material than another section. However, depending upon specific characteristics desired for the portion  100 , the distribution of the nanostructured material can be varied from that illustrated in  FIG. 1 . Thus, for example, the nanostructured material can be distributed non-linearly across the surface  106  to match a stress profile of the first layer  102  under service loads or meet a set of mass characteristics requirements, such as center-of-gravity (c.g.), balance point, moment of inertia (MOI), swing weight, or total mass. 
         [0123]    With reference to  FIG. 2 , a cross-sectional schematic view of a portion  200  of a sports article, such as metalwood, according to another embodiment of the invention is illustrated. The portion  200  is implemented in accordance with a multi-layered design and includes a first layer  202 , a second layer  204  that is adjacent to the first layer  202 , and a third layer  206  that is adjacent to the second layer  204 . In particular, the portion  200  includes a laminate structure that is formed via a lay-up of the layers  202 ,  204 , and  206 , and at least one of the layers  202 ,  204 , and  206  is formed of a nanostructured material. While three layers are illustrated in  FIG. 2 , it is contemplated that the portion  200  can include more or less layers for other implementations. 
         [0124]    The first layer  202  and the third layer  206  are formed of any suitable materials, such as fibrous materials, foams, ceramics, metals, metal alloys, polymers, or composites. Thus, for example, at least one of the first layer  202  and the third layer  206  can be formed of a graphite fiber/epoxy composite. As can be appreciated, a graphite fiber/epoxy composite can have any of a variety of forms, such as uniaxial, biaxial, woven, pre-impregnated, filament wound, tape-layered, or a combination thereof. The selection of materials forming the first layer  202  and the third layer  206  can be dependent upon a variety of considerations, such as their ability to facilitate formation of the second layer  204 , their ability to be molded or shaped into a desired form, and desired characteristics of the portion  200 . 
         [0125]    The second layer  204  is formed of a nanostructured material, such as n-Ni, n-Ni Co, n-Ni Fe, n-Co P, or a composite thereof. The selection of the nanostructured material can be dependent upon a variety of considerations, such as its ability to be molded or shaped into a desired form and desired characteristics of the portion  200 . In the illustrated embodiment, the second layer  204  is formed as a foil, a sheet, or a plate via electro-deposition. In particular, the second layer  204  is deposited on a temporary substrate using similar electro-deposition settings as previously described with reference to  FIG. 1 . It is also contemplated that the second layer  204  can be formed using any other suitable manufacturing technique. The resulting second layer  204  formed of the nanostructured material can have characteristics that are similar to those previously described with reference to  FIG. 1 . 
         [0126]    During formation of the portion  200 , the first layer  202  serves as an inner ply to which the second layer  204  and the third layer  206  are sequentially added as a middle ply and an outer ply, respectively. Once properly positioned with respect to one another, the layers  202 ,  204 , and  206  are coupled to one another using any suitable fastening mechanism, such as through inter-laminar shear strength of epoxy, an additional chemical adhesive paste, or an adhesive thin film added before a standard cure cycle that can optionally involve vacuum pressure. The portion  200  can be formed with a variety of shapes using hand lay-up, tape-layering, filament winding, bladder-molding, or any other suitable manufacturing technique. 
         [0127]    With reference to  FIG. 3 , a cross-sectional schematic view of a portion  300  of a sports article, such as a metalwood, according to a further embodiment of the invention is illustrated. The portion  300  is implemented in accordance with a multi-layered design and includes a first layer  302 , a second layer  304  that is adjacent to the first layer  302 , and a third layer  306  that is adjacent to the second layer  304 . In particular, the portion  300  includes a laminate structure that is formed via a lay-up of the layers  302 ,  304 , and  306 , and at least one of the layers  302 ,  304 , and  306  is formed of a nanostructured material. While three layers are illustrated in  FIG. 3 , it is contemplated that the portion  300  can include more or less layers for other implementations. 
         [0128]    The first layer  302  and the third layer  306  are formed of the same nanostructured material or different nanostructured materials. The selection of the nanostructured materials can be dependent upon a variety of considerations, such as their ability to be molded or shaped into a desired form and desired characteristics of the portion  300 . In the illustrated embodiment, the first layer  302  and the third layer  306  are formed as foils, sheets, or plates using similar electro-deposition settings as previously described with reference to  FIG. 1 . It is also contemplated that the layers  302  and  306  can be formed using any other suitable manufacturing technique. The resulting layers  302  and  306  can have characteristics that are similar to those previously described with reference to  FIG. 1 . 
         [0129]    The second layer  304  can be formed of a visco-elastic material that exhibits high vibration damping. The selection of the visco-elastic material can be dependent upon a variety of other considerations, such as its ability to be molded or shaped into a desired form. An example of the visco-elastic material is a visco-elastic polymer that is based on polyether and polyurethane, such as Sorbothane® brand polymers that are available from Sorbothane, Inc., Kent, Ohio. Advantageously, the use of the visco-elastic material allows the second layer  304  to serve as a constrained, vibration damping layer, thus reducing vibrations and providing a desired feel during impacts of metalwoods with golf balls. 
         [0130]    During formation of the portion  300 , the first layer  302  serves as an inner ply to which the second layer  304  and the third layer  306  are sequentially added as a middle ply and an outer ply, respectively. Once properly positioned with respect to one another, the layers  302 ,  304 , and  306  are coupled to one another using any suitable fastening mechanism, such as though inter-laminar shear strength of epoxy, an additional chemical adhesive paste, or an adhesive thin film added before a standard cure cycle that can optionally involve vacuum pressure. The portion  300  can be formed with a variety of shapes using hand lay-up, tape-layering, filament winding, bladder-molding, or any other suitable manufacturing technique. 
         [0131]    Metalwood and Face Insert Applications 
         [0132]    According to an aspect of the present invention, patches, sleeves or sections of nanostructured materials can be electro-deposited on selected areas, such as on metalwood crowns, skirts, sole plates, faces, hosels and body sections, without the need to cover an entire article. In addition, patches, sleeves or sections of nanostructured materials, which need not be uniform in thickness, can be electro-deposited in order to, for example, form a thicker coating on selected sections or sections particularly prone to heavy use, bending, and impact. 
         [0133]    Another aspect of the invention relates to a nanostructured material layer performing as the impact surface. A nanostructured layer with higher hardness will wear significantly less and show greater resistance to impact damage, cracking, cuts, nicks and abrasion, as compared to common materials used in metalwood manufacture such as FRP composites. Metalwoods with nanostructured metal applied to the outside of the fiber-reinforced composite (FRP) substrates have several advantages. The impact strength of the FRP composite with a nanostructured coating will be superior to metalwood head component, such as a driver or fairway wood crown, made from only FRP composite or neat plastic resin such as ABS or PEI. This protection can prevent the onset of fatigue cracks that would otherwise cause failure of the product. Thus the performance will be maintained throughout the product life due to the presence of the nanostructured material as a protective layer or impact surface. This is particularly important when considering the transmission of the impact loads from the face to the crown and body when golf balls are struck, or from impacts with other clubs when the metalwoods are thrown back into a golf bag, or normal wear and tear during transport as the thin-walled crown and body components are subjected to impact forces that would otherwise dent, deform or scratch the metalwood bodies themselves. Second, the nanostructured material can be applied in a controlled manner on selected areas and in variable thicknesses profiles, allowing for a wide variety of structural compliance. This produces the ability to better control the C.O.R. of the finished metalwood head by using the nanostructured material stiffness to govern the flex of the crown, and the overall frequency response function, in particular the “breathing mode shape” of the head during impacts with golf balls. Third, the strength-to-weight ratio is improved due to the presence of nanostructured material which adds structural rigidity to the FRP substrate due to the much higher Young&#39;s Modulus, E. Fourth, the application of a very and high strength nanostructured material to a metalwood component reduces the dampening of the FRP system, and improves the pitch and amplitude of the sound generated by the club head during golf ball impacts. Other advantages are also anticipated as optimal designs evolve for each metalwood category: drivers, fairway woods, hybrid and utility clubs. 
         [0134]    In one embodiment, a metalwood crown, skirt or body component having a sandwich or layered construction with a polymer substrate where one or more layer of the sandwich is a nanostructured material as shown in  FIGS. 1  thru  7  inclusive, and where the nanostructured material is used to improve the performance and durability of the metalwood as whole. The improved performance is achieved through the optimized stiffness in the design of the metalwood head which also improves the durability of the golf club by adding a wear resistant surface and provides better feel due to the vibration attenuation inherent in a multi-layered design. 
         [0135]    In one embodiment, a metallic alloy substrate may be partially or completely encapsulated by nanostructured material. The encapsulation increases the stiffness and strength of the structure. In addition, complete encapsulation prevents the possibility of corrosion of the metallic alloys substrate. Illustrations of several embodiments are shown in  FIGS. 4 ,  5  and  6 . A schematic cross section of a metallic alloy substrate completely encapsulated by the nanostructured material is shown in  FIG. 7   
         [0136]    It should be appreciated that the metallic alloy substrate or polymer substrate need not be encapsulated symmetrically. The location of the substrate in the insert can be chosen depending on the particular application. The encapsulation width along the perimeter, i.e. the material covering the perimeter of the substrate, can be controlled during the electro-deposition process and could be later machined to the design requirement. In some exemplary embodiments the encapsulation width or thickness can vary from 0 to 1 mm or more. 
         [0137]    In one embodiment, in order to make a bimetallic sandwich, a component of the sandwich structure may be an any aluminum alloy including the 1XXX pure Al, 2XXX Al—Cu, 3XXX Al—Mn, 4XXX Al—Si, 5XXX Al—Mg, 6XXX Al—Mg—Si, 7XXX Al—Zn, 8XXX series, Al—Li alloys or Sc-containing Al alloys. It is preferred that the aluminum alloy chosen is in its highest strength temper to make it an effective component. For the heat treatable alloys such as the 7XXX, 6XXX and the 2XXX series it is usually the T6 temper that is the highest strength. For non heat-treatable alloys such as 5XXX, the component material should be used in the H temper for the highest strength. 
         [0138]    Prior to nanostructured material deposition, the substrate may be subjected to an activation process. This process prepares the aluminum alloy or magnesium alloy surface to be more amenable for adhesion to the electro-deposited nanostructured material. The activation process may consist of a series of steps aimed at removing the oxide surface on aluminum alloys or magnesium alloys. Processes such as this are well-established and practiced commercially by companies such as MacDermid. A final step of the activation process can be a copper strike to promote a smoother surface and provide a conductive and readily electro-platable surface. In this final step a thin layer of copper is deposited using standard electrochemical methods. One example of such a copper strike is the “acid copper.” 
         [0139]    Metalwood components, such as faces, crowns, skirts, bodies, soles and hosels, can be fabricated either individually or as in large plates or shells with the product cut out using any suitable method. The substrate is first subjected to an activation process which is highly dependent on the substrate. Next, the activated substrate may be placed in an electro-chemical cell and the nanostructured material deposited selectively in specific areas to improve performance such as localized stiffness or impact resistance using the electro-deposition process described in previous examples. The process may be run until the required thickness of deposited material has been reached. Under controlled process conditions, equal amounts of material can deposited on each side of the substrate, as shown schematically in  FIG. 5 . 
         [0140]    In another embodiment of the invention, the nanostructured material may only be electro-deposited on one side as shown schematically in  FIG. 1 . In this case, one side of the substrate may be masked off and made electrically non-conductive. This can be achieved by wrapping a tape, painting with a lacquer, or any other suitable method. The electro-deposition process is then run until the required thickness of the nanostructured material layer is achieved. 
         [0141]    In some embodiments, different amounts of nanostructured material electro-deposition may be required. If the design of the metalwood, for example, requires that different amounts of nanostructured material be deposited on the two sides of the substrate, then the following modifications to the process may be done. 
         [0142]    In one embodiment, the nanostructured material is deposited on one side of the substrate to begin with, the other side being masked off with electrically non-conducting material. The process is run for a sufficient length of time to allow the required build up of the nanostructured material. Next, the mask may be removed and applied to the side on which nanostructured material is previously deposited. The substrate is run again for the time necessary to achieve different deposition thickness. 
         [0143]    In another embodiment of the invention, the nanostructured material is deposited on both sides of the substrate simultaneously by placing a separate anode on each side. The thickness on each side can be controlled by applying different currents to different sides of the substrate. 
         [0144]    In another embodiment, the nanostructured material is deposited on both sides of the substrates using two separate circuits as described before. The fabrication process begins with deposition from both sides. After the required thickness for one side is reached, that circuit is interrupted and a shield is dropped very close to the nanostructured metal surface to prevent any further deposition on that side. 
         [0145]    In another embodiment, the electro-deposition process is carried out in two stages. In the first stage a nanostructured material having composition A is deposited. In the second stage of the process, nanostructured material having composition B is deposited. The choice of the alloy composition will depend on the exact design requirement. For example, in some embodiments it is suggested that the alloy compositions be chosen such that the strength of alloy B is greater than alloy A. In another embodiment it is suggested that alloy B have higher fracture toughness than alloy A. In another embodiment it is suggested that alloy A have higher hardness as compared to alloy B. It should be pointed out that whether alloy A or alloy B is used as a strike/impact surface will depend on the properties of the individual compositions. 
         [0146]    In addition to the embodiments described above, it is suggested that when very precise thickness of nanostructured material is required, the nanostructured layers in the sandwich be machined or finished using operations such as surface grinding, blanchard grinding, double-disc grinding, lapping, and milling. 
         [0147]    In one exemplary embodiment of the invention for the face insert, the substrate consists of aluminum alloys 7075, 7178 and 7001 in T6 temper. The nanostructured metal consists of a nickel-iron alloy with iron content in the range of 0-50% by weight. The thickness of aluminum substrate is in the range 0.1 mm to 4.00 mm range. The front layer of nanostructured metal is in the range 0.5 mm to 2.0 mm, and the back layer of nanostructured metal is in the range 0 mm to 1.0 mm. 
         [0148]    The various components of a typical metalwood head  400  are shown schematically in  FIGS. 8 and 11 . The metalwood components generally include a crown  402 , a skirt  404 , a sole or soleplate  406 , a face/face plate/face insert  408 , a hosel  410  and a body or body section  412 . It should be noted that each of these components can be fabricated using nanostructured materials as outlined in  FIGS. 1-7  inclusive. Each of these components can be fabricated having uniform thickness or with a variable thickness. As an example, refer to  FIGS. 9 and 10 , which shows a face plate or face insert  408  having variable thickness. The components can joined using adhesives or epoxies in a lap joint configuration  420  or a trap joint configuration  430  as shown in  FIGS. 12 and 13 . An example of a fully assembled head is shown schematically in  FIG. 14 . 
         [0149]    In the event a large plate of aluminum is used as a substrate, the individual metalwood crown, face, skirt or soleplate may be cut from the sheet using processes such as water jet, laser, electro-discharge machining, CNC milling, high speed diamond saw cutting and so forth. In one exemplary embodiment, water jet is used for cutting the driver and metalwood crowns and faces from the large sheet to be assembled by standard mechanical processes such as press-fits and bolts with or without additional chemical and thin film adhesive bonding layers. 
       Examples 
       [0150]    The following examples describe specific features of some embodiments of the invention to illustrate and provide a description for those of ordinary skill in the art. The examples should not be construed as limiting the invention, as the examples merely provide specific methodology useful in understanding and practicing some embodiments of the invention. 
       Example 1  
       [0151]    A metalwood head made from stainless steel was used as a substrate. The metalwood head was cleaned thoroughly to remove any oils and greases from the surface. Next the metalwood head was activated using a Wood&#39;s nickel bath. This process allowed a very thin layer of nickel to be deposited on the surface of the metalwood. Following this treatment, the head was immediately immersed in the nano-nickel bath. A nano-nickel layer was built up to a thickness of 100 microns. The metal wood head was assembled into a club and was field tested. 
       Example 2  
       [0152]    A crown for a metalwood was fabricated from a polyamide resin using injection molding process. The surface of polyamide resin crown was activated to make the surface amenable for electro deposition. The activated polyamide crown was connected to an electrical circuit and nano-nickel was deposited to a thickness of 50 microns. The nano-nickel deposited crown was subjected to an endurance and sound test. The endurance test consists of dropping a sharp dart on the crown from a pre-determined height. After the dart impacts the surface is examined for dents and other damage. A crown is considered to have passed the test if the dart drop height is more than 24 inches. The nano-nickel coated crown passed the endurance test while the non-coated crown failed the test. Additionally, the nano-nickel coated crown was judged to sound better or more metal like while the sound from a non-metal coated crown was judged poor. 
         [0153]    Golf iron face inserts can be fabricated either individually or as in large plates or shells with the product cut out using any suitable method. Whether starting with an individual aluminum, magnesium, or plastic substrate or a sheet of said materials, the substrate may be first subjected to an activation process. Next, the activated substrate may be placed in an electrochemical cell and the nanostructured material deposited selectively in specific areas to improve performance such as localized stiffness or impact resistance using the electro-deposition process described in previous examples. The process may be run until the required thickness of deposited material has been reached. Under controlled process conditions, equal amounts of material can deposited on each side of the substrate, as shown schematically in  FIG. 5 . 
         [0154]    In another embodiment of the invention, the nanostructured material may only be electro-deposited on one side as shown in  FIG. 1 . In this case, one side of the substrate may be masked off and made electrically non-conductive. This can be achieved by wrapping a tape, painting with a lacquer, or any other suitable method. The electro-deposition process is then run until the required thickness of the nanostructured material layer is achieved. 
         [0155]    In some embodiments different amounts of nanostructured material electro-deposition may be required. If the design of the metalwood, for example, requires that different amounts of nanostructured material be deposited on the two sides of the substrate, then the following modifications to the process may be done. 
         [0156]    In one embodiment, the nanostructured material is deposited on one side of the substrate to begin with, the other side being masked off with electrically non-conducting material. The process is run for a sufficient length of time to allow the required build up of the nanostructured material. Next, the mask may be removed and applied to the side on which nanostructured material is previously deposited. The substrate is run again for the time necessary to achieve different deposition thickness. 
         [0157]    In another embodiment of the invention, the nanostructured material is deposited on both sides of the substrate simultaneously by placing a separate anode on each side. The thickness on each side can be controlled by applying different currents to different sides of the substrate. 
         [0158]    In another embodiment, the nanostructured material is deposited on both sides of the substrate using two separate circuits as described before. The fabrication process begins with deposition from both sides. After the required thickness for one side is reached, that circuit is interrupted and a shield is dropped very close to the nanostructured metal surface to prevent any further deposition on that side. 
         [0159]    In another embodiment, the electro-deposition process is carried out in two stages. In the first stage a nanostructured material having composition A is deposited. In the second stage of the process, nanostructured material having composition B is deposited. The choice of the alloy composition will depend on the exact design requirement. For example, in some embodiments it is suggested that the alloy compositions be chosen such that the strength of alloy B is greater than alloy A. In another embodiment it is suggested that alloy B have a higher fracture toughness than alloy A. In another embodiment it is suggested that alloy A have a higher hardness as compared to alloy B. It should be pointed out that whether alloy A or alloy B is used as a strike/impact surface will depend on the properties of the individual compositions. 
         [0160]    In addition to the embodiments described above, it is possible to electro-deposit nanostructured material equally on each side of the substrate. The exact thickness of the individual nanostructured layers in the sandwich can then be achieved by machining or finishing operations such as surface grinding, Blanchard grinding, double-disc grinding, lapping, and milling to remove excess material. 
         [0161]    In one exemplary embodiment of the invention the substrate consists of aluminum alloys 7075, 7178 and 7001 in a T6 temper. The nanostructured metal consists of a nickel-iron alloy with iron content in the range of 0-50% by weight. The thickness of aluminum substrate is in the range 0.1 mm to 4.00 mm range. The front layer of nanostructured metal in the range 0.5 mm to 2.0 mm range, and the back layer of nanostructured metal in the range 0 mm to 1.0 mm range. 
         [0162]    In the event a large plate of aluminum is used as a substrate, the individual face insert may be cut from the sheet using processes such as water jet, laser, electro-discharge machining, CNC milling, high speed diamond saw cutting and so forth. In one exemplary embodiment, water jet is used for cutting the face inserts from the large sheet to be assembled by standard mechanical processes such as swaging, press-fits and bolts with or without additional chemical and thin film adhesive bonding layers. 
       Example 3  
       [0163]    A 12″×12″×0.060″ thick 7075-T6 aluminum plate was used as a substrate for making iron face inserts. The aluminum plate was activated prior to electro-depositing nano crystalline nickel metal. The purpose of activation is to make the aluminum surface amenable to plating. Without the activation layer the nano metal will not adhere to the aluminum surface and consequently would be rendered useless in application. The activation step consisted of cleaning, followed by double zincate followed by a nickel strike and finished with a copper strike. The copper strike protects the aluminum from corrosion and other environmental degradation. The activated aluminum plate was hooked up to an electrical circuit and nano crystalline nickel was deposited on both sides of the plate. Prior to electrodeposition of the nano-crystalline metal the copper was activated by dipping it in a suitable activator solution. Exact shapes corresponding to the face insert geometry were cut out from the plate using water jet. The face inserts were next swaged into the head cavity. Additional adhesion was provided by epoxy bonding the back side of the insert to the cavity. Excess metal after swaging was milled off and grooves were machined on the impact side of the face. The finished head was joined to a suitable shaft and the resulting club was found to be superior in feel when tested by players. 
         [0164]    The photographs of aforementioned examples reduced to practice are shown in  FIGS. 15 through 20  of this document. 
         [0165]    A practitioner of ordinary skill in the art requires no additional explanation in developing the embodiments described herein but may nevertheless find some helpful guidance regarding characteristics and formation of nanostructured materials by examining the patent application of Palumbo et al., U.S. patent application Ser. No. 11/013,456, entitled “Strong, Lightweight Article Containing a Fine-Grained Metallic Layer” and filed on Dec. 17, 2004, and the patent application of Palumbo et al., U.S. patent application Ser. No. 10/516,300, entitled “Process for Electro-plating Metallic and Metal Matrix Composite Foils, Coatings and Microcomponents” filed on Dec. 9, 2004, and the patent application of Palumbo, et al., U.S. application Ser. No. 11/305,842, entitled “Sports Articles Formed Using Nanostructured Materials” filed on Dec. 16, 2005, the disclosures of which are incorporated herein by reference in their entirety. 
         [0166]    As is evident from the foregoing, one or more embodiments of the present invention may comprise nanostructured material electro-deposited on some portion of a driver head, a fairway wood head, a hybrid iron club head, a hybrid wood club head, a utility club head, a utility iron club head, a utility wood club head, an iron-wood head and a rescue-style club head. The nanostructured material can be electro-deposited on some portion, including the inside, outside or both of a driver head with a loft between 7 and 14 degrees. The nanostructured material can be electro-deposited on some portion, including the inside, outside or both of a fairway wood head with a loft between 10 and 25 degrees. The nanostructured material can be electro-deposited on some portion, including the inside, outside or both of an iron club head with a loft between 18 and 50 degrees. The nanostructured material can be electro-deposited on some portion, including the inside, outside or both of a wedge head with a loft between 45 and 64 degrees. Further, the electro-deposited coating of nanostructured material can be different on the inside versus the outside of a component. 
         [0167]    A golf club head defined herein can be a range of golf club heads known as “putters” used for the game golf including all the variations of putter heads, such as mallet, half-mallet, over-sized, blade, long hosel, short hosel, bent hosel, center-shafted, alignment, including others permutations not mentioned herein which are found to be conforming to the Rules of Golf as established by the U.S.G.A. of Far Hills, N.J., U.S.A, and/or the R&amp;A of St. Andrew&#39;s Scotland, UK. The nanostructured material can be electro-deposited on some portion, including the inside, outside or both of a putter head with a loft between 0 and 7 degrees. 
         [0168]    The performance (e.g., the vibro-acoustic performance, durability and strength) of the metalwood is improved by electro-depositing various thicknesses of nanostructured material onto more than one of the sub-components of a metalwood: the face, the hosel, the crown, the skirt, the sole plate, and the body. 
         [0169]    While the invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention as defined by the appended Claims. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, method, operation or operations, to the objective, spirit and scope of the invention. All such modifications are intended to be within the scope of the Claims appended hereto, and their equivalents. In particular, while certain methods may have been described with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the invention. Accordingly, unless specifically indicated herein, the order and grouping of the operations is not a limitation of the invention.