Abstract:
A coating includes a nano-composite layer including a plurality of films. The films are stacked together one after another. Each film includes a zirconium-copper carbonitride layer and a zirconium carbonitride layer.

Description:
The present application is related to co-pending U.S. patent application 13/007,706, entitled “COATING, ARTICLE COATED WITH COATING, AND METHOD FOR MANUFACTURING ARTICLE”, by Zhang et al. This application has the same assignee as the present application and has been concurrently filed herewith. The above-identified applications are incorporated herein by reference. 
     BACKGROUND 
     1. Technical Field 
     The exemplary disclosure generally relates to coatings, and particularly relates to articles coated with the coatings and a method for manufacturing the articles. 
     2. Description of Related Art 
     Physical vapor deposition (PVD) has conventionally been used to form a coating on metal bases of cutting tools or molds. Materials used as this coating material are required to have good durability. At present, Zirconium carbonitride (ZrCN) is used as a material satisfying these requirements. However, ZrCN poorly adheres to metal properties and may easily peel off. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the exemplary coating, article coated with the coating and method for manufacturing the article. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment. 
         FIG. 1  is a cross-sectional view of an exemplary embodiment of a coating. 
         FIG. 2  is a cross-sectional view of an article coated with the coating in  FIG. 1 . 
         FIG. 3  is a block diagram showing the steps of an exemplary method for manufacturing the article in  FIG. 2 . 
         FIG. 4  is a schematic view of a magnetron sputtering coating machine for manufacturing the article in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     A coating  30  includes a deposited layer  31 . The deposited layer  31  is a zirconium-copper carbonitride (ZrCuCN) layer. The deposited layer  31  may be deposited by magnetron sputtering or cathodic arc deposition. 
     The deposited layer  31  has a thickness ranging from about 1 micrometers to about 3 micrometers. In this exemplary embodiment, the thickness of the deposited layer  31  is 2 micrometers. It is to be understood that the coating may include a color layer  33  covering on the deposited layer  31 , to decorate the appearance of the coating  30 . 
     Referring to  FIG. 2 , an exemplary article  40  includes a substrate  10 , a bonding layer  20  deposited on the substrate  10  and the coating  30  deposited on the bonding layer  20 . The substrate  10  is made of metal, such as high speed steel, hard alloy, or stainless steel. The article  40  may be cutting tools, mold, or housings of electronic devices. The bonding layer  20  is a zirconium copper (ZrCu) layer. The bonding layer  20  has a thickness ranging from about 0.05 micrometer to about 0.2 micrometer. The bonding layer  20  can be deposited by magnetron sputtering or cathodic arc deposition. The chemical stability of the bonding layer  20  is between the chemical stability of the substrate  10  and the chemical stability of the coating  30 , and the coefficient of thermal expansion of the bonding layer  20  is between the coefficient of thermal expansion of the substrate  10  and the coefficient of thermal expansion of the coating  30 . Thus, the bonding layer  20  is used to improve binding between the substrate  10  and the coating  30  so that the coating  30  can be firmly deposited on the substrate  10 . 
     Referring to  FIG. 3 , a method for manufacturing the article  40  may include at least the following steps. 
     A substrate  10  is provided. The substrate  10  may be made of high speed steel, hard alloy, or stainless steel. 
     The substrate  10  is pretreated. Firstly, the substrate  10  is washed with a solution (e.g., Alcohol or Acetone) in an ultrasonic cleaner, to remove, e.g., grease, dirt, and/or impurities. Secondly, the substrate  10  is dried. Thirdly, the substrate  10  is cleaned by argon plasma cleaning. The substrate  10  is retained on a rotating bracket  50  in a vacuum chamber  60  of a magnetron sputtering coating machine  100 . The vacuum level of the vacuum chamber  60  is adjusted to 8.0×10-3 Pa. Pure argon is floated into the vacuum chamber  60  at a flux of about 300 sccm (Standard Cubic Centimeters per Minute) to 600 sccm from a gas inlet  90 , and a bias voltage is applied to the substrate  10  in a range about −300 to −800 volts for about 3-10 minutes. So the substrate  10  is washed by argon plasma, to further remove the grease or dirt. Thus, the binding force between the substrate  10  and the bonding layer  20  is enhanced. 
     A bonding layer  20  is deposited on the substrate  10 . The argon is floated into the vacuum chamber  60  at a flux from about 100 sccm to 300 sccm from the gas inlet  90 , preferably is about 150 sccm; a zirconium copper alloy target  70  is evaporated; a bias voltage applied to the substrate  10  may be in a range about −100 to −300 volts for about 5 to 20 min (preferably is 10 min), to deposit the bonding layer  20  on the substrate  10 . The zirconium copper alloy contains zirconium in a range about 30 to about 70 wt %. 
     A deposited layer  31  is deposited on the bonding layer  20 . The temperature in the vacuum chamber  60  is adjusted to 100˜200° C. Nitrogen is floated into the vacuum chamber  60  at a flux from about 10 sccm to about 100 sccm and acetylene gas is floated into the vacuum chamber  60  at a flux from about 10 sccm to about 100 sccm from the gas inlet  90 ; the zirconium copper alloy target  70  is continuously evaporated in a power from 7 kw to 11 kw for a time from 30 min to 180 min (preferably is 60 min), to deposit the deposited layer  31  on the bonding layer  20 . During depositing the deposited layer  31 , atomic copper and atomic zirconium can not react to solid solution phase, and atomic copper is not easily to react with atomic nitrogen, so atomic nitrogen has a priority of reaction with atomic zirconium to form zirconium-nitrogen crystal. Additionally, atomic copper is independently from copper phase at the boundary of the zirconium-nitrogen crystal, which can prevent the zirconium-nitrogen crystal from enlarging, to maintain the zirconium-nitrogen crystal in nanometer level. The nanometer lever zirconium-nitrogen can improve hardness and toughness of the coating  30 . 
     It is to be understood that the color layer  33  may be deposited on the deposited layer  31  to improve the appearance of the article  40 . 
     It is to be understood, however, that even through numerous characteristics and advantages of the exemplary disclosure have been set forth in the foregoing description, together with details of the system and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.