Patent Publication Number: US-2020283923-A1

Title: Method and apparatus for continuously applying nanolaminate metal coatings

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/052,345, filed Sep. 18, 2014, which application is incorporated herein by reference in its entirety. In addition the disclosures of U.S. Provisional Application No. 61/802,102, filed Mar. 15, 2013, and International Patent Application No. PCT/US2014/31101, filed Mar. 18, 2014, are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     Nanolaminate materials have become widely studied over the past several decades. As a result some desirable advanced performance characteristics of those materials have been discovered and their potential application in numerous fields recognized. While the potential application of nanolaminated materials in numerous areas, including civil infrastructure, automotive, aerospace, electronics, and other areas, has been recognized, the materials are on the whole not available in substantial quantities due to the lack of a continuous process for their production. 
     SUMMARY 
     Described herein are apparatus and methods for the continuous application of nanolaminated materials by electrodeposition. 
     In some embodiments, the method imparts a stable mechanical and chemical finish to materials (e.g., steel) that is resistant to corrosion or that can receive a durable finish (e.g., paint powder coat, etc.). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  show a top and side view, respectively, of a plating cell according to various embodiments disclosed herein; 
         FIGS. 2A and 2B  show a top and side view, respectively, of a triple rinse unit according to various embodiments disclosed herein; 
         FIGS. 3A and 3B  show a top and side view, respectively, of a combined plating cell and triple rinse unit according to various embodiments described herein; 
         FIGS. 4A and 4B  show a top and side view, respectively, of a quintuple rinse unit according to various embodiments disclosed herein; 
         FIGS. 5A and 5B  show a top and side view, respectively, of a combined plating cell and double rinse unit according to various embodiments disclosed herein; 
         FIGS. 6A and 6B  show a top and side view, respectively, of a combined immersion cell and quintuple rinse unit according to various embodiments disclosed herein; 
         FIGS. 7A and 7B  show a top and side view, respectively of a forced air dryer according to various embodiments disclosed herein; 
         FIGS. 8A and 8B  show a top and side view, respectively, of a strip puller according to various embodiments described herein; 
         FIGS. 9A and 9B  show a top and side view, respectively, of a storage tank according to various embodiments described herein; 
         FIGS. 10A and 10B  show a top and side view, respectively, of a storage tank according to various embodiments described herein; 
         FIGS. 11A and 11B  show a top and side view, respectively, of a storage tank according to various embodiments described herein; 
         FIGS. 12A and 12B  show a top and side view, respectively, of a storage tank according to various embodiments described herein; 
         FIGS. 13A and 13B  show a top and side view, respectively, of a storage tank according to various embodiments described herein; 
         FIG. 14  shows a piping and instrumentation configuration for a plating cell according to various embodiments described herein; 
         FIG. 15  shows a piping and instrumentation configuration for a triple countercurrent rinse unit according to various embodiments described herein; 
         FIG. 16  shows a piping and instrumentation configuration for an immersion cell according to various embodiments described herein; 
         FIG. 17  shows a piping and instrumentation configuration for a chromate coating cell according to various embodiments described herein; 
         FIGS. 18A and 18B  show top and side views, respectively, of a continuous nanolaminate coating process line including 15 plating cells according to various embodiments described herein; and 
         FIG. 19  shows a continuous processing apparatus for the application of nanolaminated coatings configured for conductive materials that can be rolled. 
     
    
    
     DETAILED DESCRIPTION 
     1.0 Definitions 
     “Electrolyte” as used herein means an electrolyte bath, plating bath, or electroplating solution from which one or more metals may be electroplated. 
     “Workpiece” means an elongated conductive material or loop of conductive material. 
     “Nanolaminate” or “nanolaminated” as used herein refers to materials or coatings that comprise a series of layers less than 1 micron. 
     All compositions given as percentages are given as percent by weight unless stated otherwise. 
     2.0 Electrodeposition Apparatus for Continuous Application of Nanolaminated Coatings 
     2.1 Exemplary Electrodeposition Apparatus 
       FIGS. 1A-19  show various process units that may be used in various combinations to form a continuous electrodeposition process line capable of performing the continuous application of nanolaminate coatings on conductive materials. 
     A main component of the process line is the plating cell  100  shown in  FIGS. 1A and 1B . The plating cell  100  is where the application of nanolaminate coatings on conductive materials is carried out, and generally includes an enclosure  110 , a cathode brush assembly  120 , an anode assembly  130 . As shown in  FIGS. 1A and 1B , the plating cell  100  includes two each of the cathode brush assembly  120  and anode assembly  130  in enclosure  110  such that two workpieces can be plated in parallel. 
     The enclosure  110  is generally a tank or vessel in which the other components of the plating cell  100  are located. The enclosure  110  is capable of containing electrolyte solution within the walls of the enclosure  110 . Any suitable material can be used for the enclosure, including, for example, polypropylene. The dimensions of the enclosure are generally not limited. In some embodiments, the enclosure is approximately 3 feet long, 2 feet wide, and 1 foot, 2 inches tall. 
     The enclosure  110  includes one or more inlets  111  where electrolyte solution can be introduced into the enclosure  110 . The flow of electrolyte solution into the enclosure  110  via the inlets  111  can be controlled via flow control valves  112 . In some embodiments, the inlets are positioned within the anode assembly  130  so that the inlets  110  provide electrolyte solution into the anode assembly  130  positioned within the enclosure  110 . The enclosure  110  can also include one or more drains  113  for allowing electrolyte solution to be drained from the enclosure  110 . The enclosure  110  can be covered with a fold back lid  114  so that the interior of the enclosure  110  can be sealed off from the outside environment. The enclosure  110  can also include one or more ventilation slots  115  for safely venting gases from the interior of the enclosure  110 . 
     As shown in  FIG. 1A , the enclosure  110  further includes an inlet passage  116  and an outlet passage  117  at opposite ends of the enclosure  110 . The inlet passage  116  and the outlet passage  117  are generally narrow vertical slits (e.g., 0.5 inches wide) in the enclosure  110  through which the workpiece passes into and out of the enclosure  110 . In some embodiments, the passages  116 ,  117  do not extend the entire height of the enclosure  110 . In some embodiments, the passages  116 ,  117  terminate approximately 3 inches above the bottom of the enclosure  110 . An inlet passage  116  and an outlet passage  117  is provided for each line in the enclosure  110 . For example, in the configuration shown in  FIG. 1A , the enclosure  110  will include two inlet passages  116  and two outlet passages  117 , one each for the parallel two process lines in the enclosure  110 . 
     Although not shown in the remaining figures, similar inlet and outlet passages can be provided in all of the units described herein to allow for passage of the workpiece into and out of the individual units. 
     The cathode brush assembly  120  provides a manner for passing a current to the workpiece that will serve as the cathode in the plating cell  100 . Accordingly, the cathode brush assembly  120  typically includes a structure that is connected to a power supply (not shown in  FIGS. 1A and 1B ) and is capable of passing a current to the workpiece as it passes against the cathode brush assembly  120 . The cathode brush assembly can be made from any material suitable for receiving a voltage and conductively passing a current to the workpiece. 
     In some embodiments, the cathode brush assembly  120  includes an arm  121  extending from the cathode brush assembly  120 . The arm  121  extending from the cathode brush assembly  120  can terminate at a vertically oriented rod  122   a . A second vertical rod  122   b  may be spaced apart from the vertically oriented rod  122   a  to thereby form a narrow passage between the vertically oriented rods  122   a ,  122   b . The workpiece passes through this passage and contacts the vertically oriented rod  122   a  to thereby pass a current to the workpiece. In some embodiments, one or both of the rods  122   a ,  122   b  are flexible. 
     The anode assembly  130  is an open vessel or tank located within the larger enclosure  110 . The anode assembly  130  may include one or more vertical pillars  131  positioned throughout the anode assembly  130 . In some embodiments, such as shown in  FIG. 1A , the pillars  131  form two rows. The workpiece travels between the two rows of pillars  131 , which are used as safety guards against the workpiece contacting the anode  132  located between the pillars  131  and the side walls of the anode assembly. In some embodiments, the vertical pillars  131  are perforated riser tubes. 
     The anode  132  in the anode assembly  130  may be made of any material suitable for use in electrodeposition of nanolaminate layers on a conductive material. The anode is connected to the same power supply (not shown in  FIGS. 1A and 1B ) as the corresponding cathode brush assembly  120  to thereby provide for the flow of electrons through the electrolyte solution and formation of nanolaminate layers on the workpiece. Electrolyte solution is contained within the anode assembly  130 , and as a result, the plating of material on the workpiece passing through the anode assembly  130  takes place in the anode assembly  130 . 
     The anode (which serves as an anode except during reverse pulses) may be inert or may be active, in which case the anode will contain the metal species that is to be deposited and will dissolve into solution during operation. 
     In some embodiments, the distance between the workpiece travelling through the plating cell  100  and the anode  132  may be adjusted in order to adjust various characteristics of the nanolaminate layers being deposited on the workpiece, such as the thickness of the nanolaminate layers. In some embodiments, the anode  132  is adjustable and may be positioned closer to the side walls of the anode assembly (in order to create a greater distance between the workpiece and the anode) or closer to the pillars (in order to decrease the distance between the workpiece and the anode). In some embodiments, the location of the workpiece as it travels through the anode assembly can be adjusted in order to move it closer or further away from a specific side wall of the anode assembly. In such embodiments, moving the workpiece so that it does not travel along a center line of the anode assembly (and is therefore not equidistant between the anodes at either side wall of the anode assembly) can result in different nanolaminate coatings depositing on either side of the workpiece (e.g., nanolaminate layers of differing thicknesses). 
     As shown in  FIG. 1A , the anode assembly  130  further includes an inlet passage  133  and an outlet passage  134  at opposite ends of the anode assembly  130 . The inlet passage  133  and the outlet passage  134  are generally narrow vertical slits (e.g., 0.25 inches wide) in the anode assembly  130  through which the workpiece passes into and out of the anode assembly  130 . 
     Although not shown in the remaining figures, similar inlet and outlet passages can be provided in any of the vessels disposed within larger units as described herein to allow for passage of the workpiece into and out of the vessels. 
     While not shown in  FIGS. 1A and 1B , the plating cell, and more specifically, the anode assembly, may also include a mechanism for agitating the electrolyte solution. Mixing of electrolyte in the plating cell may be provided by solution circulation, a mechanical mixer, ultrasonic agitators, and/or any other manner of agitating a solution known to those of ordinary skill in the art. While bulk mixing can be provided by a mixer, which can be controlled or configured to operate at variable speeds during the electrodeposition process, the plating cell may optionally include one or more ultrasonic agitators. The ultrasonic agitators of the apparatus may be configured to operate independently in a continuous or in a non-continuous fashion (e.g., in a pulsed fashion). In one embodiment, the ultrasonic agitators may operate at about 17,000 to 23,000 Hz. In another embodiment, they may operate at about 20,000 Hz. 
     With reference to  FIGS. 2A and 2B , a rinse unit  200  is shown wherein electrolyte and/or other process solutions may be rinsed off the workpiece. The rinse unit  200  shown in  FIGS. 2A and 2B  is a triple rinse unit containing three rinse stages. The rinse unit  200  can include any suitable number of stages. For example,  FIGS. 4A and 4B  show a quintuple rinse unit  400  including five rinse stages, while  FIGS. 5A and 5B  show a double rinse unit  500  paired with a plating cell  100 . The depth and height of the rinse unit will typically be the same as the plating cell (e.g., 2 feet wide, 1 foot, 2 inches deep), while the length of the rinse unit will depend on the number of stages. In some embodiments, the triple rinse unit shown in  FIGS. 2A and 2B  is 1 foot long, the quintuple rinse shown  FIGS. 4A and 4B  is 1 foot, 6 and ⅝ inches long, and the double rinse unit shown in  FIGS. 5A and 5B  is 8 and ¾ inches long. 
     The rinse unit  200  generally includes an enclosure  210 . The enclosure  210  is a closed tank or vessel through which the workpiece may pass. The enclosure  210  may be made from any suitable material, and in some embodiments, is made from polypropylene. The enclosure may include a lid  211  and an exhaust strip  212  for safely venting gas and vapor from the rinse unit  200 . The enclosure  210  may also include inlet and outlet passages (not shown) located at either end of the enclosure to allow for the passage of the workpiece into and out of the enclosure  210 . As with the inlet passages described above with respect to the enclosure  110  of the plating cell, the passages are generally narrow, vertical slits. 
     The rinse unit  200  further includes one or more spreader pipes  220  for each stage of the rinse unit  200 . As shown in  FIGS. 2A and 2B , each stage of the rinse unit  200  includes two spreader pipes  220 . Rinse solution (e.g., water) is dispensed from the spreader pipes  220  to rinse process solution and/or other materials from the workpiece passing through the rinse unit  200 . In some embodiments, the spreader pipe  220  is flexible tubing to allow for various positioning of the spreader pipe within the rinse unit  200 . 
     Each spreader pipe  220  can be associated with a rinse inlet  221  that provides rinse solution into the rinse unit  200  via the spreader pipe  220 . Each rinse inlet  221  may be controlled by a flow control valve  222 . The rinse unit  200  may also include one or more drains  230  to allow for the draining of rinse solution and process solution from the rinse unit  200 . 
     As shown in  FIGS. 2A and 2B , the rinse unit may also include a cathode brush assembly  120 . The cathode brush assembly is similar or identical to the cathode brush assembly  120  located in the plating cell  100  and described in greater detail above. The cathode brush assembly  120  serves as a guide to help guide the workpiece through the rinse unit. The cathode brush assembly  120  also provides a means to continue to charge the workpiece as it travels down the process line. 
       FIGS. 3A and 3B  show a plating cell  100  and rinse unit  200  combined together to form a part of the overall process line for electrodeposition of nanolaminate material. In this configuration, the outlet passage  117  of the enclosure  110  of the plating cell is aligned with the inlet passage of the enclosure  210  of the rinse unit  200  so that the workpiece can move from the plating cell  100  into the rinse unit  200 . In some embodiments, a saddle or seal (not shown) can be used to hold together the plating cell  100  and the rinse unit  200  and prevent leakage between the units. Similar saddles or seals can be used to join together any two units described herein in order to e.g., prevent leakage of process fluid out of the units and/or into an adjoining unit. 
     With reference now to  FIGS. 6A and 6B , an immersion unit  600  combined with a rinse unit  200  (quintuple rinse) is shown. The immersion unit  600  can be used to carry out, for example, acid activation on the workpiece after the plating steps have been carried out. The immersion unit  600  generally includes an enclosure  610  and an immersion vessel  620  positioned within the enclosure  610 . 
     The enclosure  610  is generally a tank or vessel suitable for containing the process solutions used in the acid activation step. The enclosure  610  can be made from any material suitable for containing the process solution used in an acid activation process. In some embodiments, the enclosure  610  includes one or more drains  611  for draining process solution out of the enclosure  610 . The enclosure  610  may also include inlet and outlet passages which allow the workpiece to pass into and out of the enclosure  610 . As described above with respect to, for example, the plating cell, the inlet and outlet passages may be narrow vertical gaps. 
     The immersion vessel  620  is a tank or vessel into which the process solution for acid activation is flowed. In some embodiments, the immersion vessel  620  includes a perforated plate floor through which process solution flows in order to fill the immersion vessel  620 . Process solution may be introduced into the immersion vessel  620  via inlet  621 . Flow of process solution into the immersion vessel  620  via inlet  621  can be controlled by flow control valve  622 . The immersion vessel  620  may also include one or more guide rollers  623  around which the workpiece winds in order to increase the amount of time the workpiece remains in the immersion vessel  620 . The immersion vessel  620  may include an inlet passage and an outlet passage at opposite ends of the immersion vessel so that the workpiece can pass into and out of the immersion vessel. The inlet and outlet passages are typically narrow vertical gaps. With reference to  FIGS. 7A and 7B , a forced air dryer  700  suitable for use in the process line is shown. The forced air dryer  700  may be any suitable type of forced air dryer capable of drying the workpiece as it passes through the forced air dryer. As shown in  FIGS. 7A and 7B , the forced air dryer  700  may be configured to include a narrow passage  710  through which the workpiece can pass. The narrow passage may be formed by insulated blocks  711 . The forced air dryer  700  may be contained within an enclosure  720 , such as the tank of a vessel, that includes a lid  721 . In some embodiments, hot air is introduced into the forced air dryer  700  from one or more inlets located under the forced air dryer  700 . The dimensions of the forced air dryer are generally not limited. In some embodiments, the forced air dryer has the same height and width as the other units of the process line (e.g., 2 feet wide, 1 foot, 2 inches tall), while the length is 2 feet long. 
       FIGS. 8A and 8B  show a strip puller  800  which can be used to pull the workpiece through the process line. The strip puller may include a plurality of rollers  810  which work to pull the workpiece through the process line. Any suitable number of rollers  810  can be used. In some embodiments, one of the rollers  810  can be a collection roller around which the processed workpiece is wound for storage. The rollers  810  can be positioned on top of a table  820  as shown in  FIGS. 8A and 8B . As also shown in  FIGS. 8A and 8B , the strip puller  800  can include a cathode brush assembly  120  for guiding the workpiece towards the rollers  810  and applying a current to the workpiece. The strip puller  800  can be used to adjust the speed at which the workpiece is pulled through the process line. 
       FIGS. 9A, 9B, 10A, 10B, 11A, 11B, 12A, 12B, 13A, and 13B  illustrate top and side views of various holding tanks suitable for use in the process line disclosed herein. The tanks are capable of holding a variety of process solutions, and will generally be made of various materials suitable for containing whatever type of process solution is to be held within the tank. Each tank may optionally include a cover where necessary. In some embodiments, the tanks may include partitions, such as shown in  FIG. 10A . 
       FIG. 14  shows an exemplary piping and instrumentation configuration for a plating cell  100 . The plating cell  100  is similar or identical to the plating cell shown in  FIGS. 1A and 1B , including an enclosure  110 , a cathode brush assembly  120 , and an anode assembly  130  having an anode  132 . The configuration includes a power supply  1410  and a holding tank  1420 . 
     The holding tank  1420  is used to hold a supply of electrolyte solution. The holding tank  1420  further includes a pump  1421  and an input line  1422 . The pump  1421  is used to pump electrolyte solution to the anode assembly  130  via line  1422 . Line  1422  can be split one or more times so that a supply of electrolyte solution is provided to each inlet  111  (e.g., as in the case of the two inlets  111  shown in  FIG. 14 ). The flow of the electrolyte solution from the holding tank  1420  into the anode assembly  130  can be controlled via the flow control valves  112 . As shown in  FIG. 14 , the input line  1422  can also include various flow meters, pressure meters, and valves as desired. An outlet line  1423  can also be provided in order to return electrolyte solution back to the holding tank  1420 . The outlet line  1423  fluidly connects the drains  113  in the enclosure  110  to the holding tank  1420 . 
     The power supply  1410  is connected to each of the cathode brush assemblies  120  and anodes  132  located in the plating cell  100 . A line  1411  connects a negative terminal of the power supply to the cathode brush assembly  120 . A line  1412  connects a positive terminal to the anode  132 . 
       FIG. 15  shows an exemplary piping and instrumentation configuration for a three stage rinsing unit  200 . The rinsing unit  200  can be similar or identical to the rinse unit  200  shown in  FIGS. 2A and 2B . The configuration includes a holding tank  1510  that includes two partitions  1511  to provide three separate holding areas within the holding tank  1510 . A pump  1520  is provided in each area so that the process solution in each area can be pumped to the rinse unit. In some embodiments, the rinse unit  200  uses three separate process solutions, thus making the configuration shown in  FIG. 15  well adapted for the three stage rinse unit  200 . A line  1512  connects each area to an inlet  221  in the rinse unit  200 . Each inlet  221  is associated with a spreader pipe  220 . The line  1512  can be split in order to provide process solution to each inlet  221  within a stage of the rinse unit  200 , and each line  1512  can include a flow control valve  222  in order to control the flow of rinse solution into the rinse unit  200 . As shown in  FIG. 15 , the input lines  1511  can also include various flow meters, pressure meters, and valves as desired. 
     Outlet lines  1513  can also be provided to allow for the return of process solution back to the holding tank  1510 . The outlet lines  1513  are in fluid communication with the drains  230  of the rinse unit. 
     With reference to  FIG. 16 , an exemplary piping and instrumentation configuration for an immersion unit  600  and a five stage rinsing unit  200  is shown. The immersion unit  600  and five stage rinsing unit  200  are similar or identical to those shown in  FIGS. 6A and 6B . The configuration includes two holding tanks  1610  and  1620 . Holding tank  1610  holds process fluid for use in the immersion unit  600  and holding tank  1620  holds process fluid for the five stage rinse unit  200 . 
     Holding tank  1610  includes a pump  1611  for pumping process fluid from the holding tank  1610  to the immersion unit  600 . An inlet line  1612  extends between the pump  1611  and the inlet  621  in the immersion vessel  620 . The line  1612  may be split into two more lines to feed multiple inlets  621 . As shown in  FIG. 16 , the line  1612  splits once so that two lines can fluidly connect with the inlet  621  in each of the two immersion vessels  620 . The line  1612  can further include flow control valves  622  to control the flow of process fluid into the immersion vessels  620 . The line  1612  can include various flow meters, pressure meters, and valves as desired. 
     An outlet line  1613  can also be provided to allow for the return of process solution back to the holding tank  1610 . The outlet line  1613  is in fluid communication with the drain  611  of the enclosure  610 . 
     Holding tank  1620  is similar to holding tank  1510  shown in  FIG. 15 . The holding tank includes two partitions  1621  to separate the holding tank  1620  into three separate holding areas. Each area includes a pump  1622  used for pumping process fluid from the holding tank to a stage of the rinse unit  200 . Each pump  1622  is in fluid communication with an inlet line  1623  that terminates at the inlets  221  of the rinse unit  200 . Each line  1623  can be split to service both different inlets  221  within a single stage and inlets in different stages of the rinse unit  200 . For example, as shown in  FIG. 15 , an inlet line  1623  splits into four different lines so that two inlets  221  in one rinse stage and two inlets  221  in another, adjacent stage can be supplied by the one line  1623 . Each line servicing an inlet  221  can include a flow control valve  222  for controlling the flow of process solution to the inlet. Each line  1623  can include various flow meters, pressure meters, and valves as desired. 
     Outlet lines  1624  can also be provided to allow for the return of process solution back to the holding tank  1620 . The outlet line  1624  is in fluid communication with the drain  230  of the rinse unit  200 . Where two or more stages are supplied with the same process solution via inlet line  1623 , the outlet lines  1624  are arranged so that the drained process solution from adjacent stages using the same process solution are returned to the appropriate partitioned area of the holding tank  1620 . 
       FIG. 17  shows an exemplary piping and instrumentation configuration for a pH control system suitable for use in controlling the pH of the electrolyte solution used in a plating cell. The piping and instrumentation used to deliver electrolyte solution from the tank  1420  to the plating cell is similar or identical to the piping and instrumentation shown in  FIG. 14 . The tank  1420  further includes tank  1710  filled with process solution suitable for adjusting the pH of the electrolyte solution as needed. An inlet line  1720  is provided from the tank  1710  to the tank  1420  so that process solution for adjusting the pH of the electrolyte solution can be delivered to the tank  1420  as needed. Instrumentation  1730  used to monitor the pH of the electrolyte solution is provided in the tank  1420 . This instrumentation  1730  is capable of sending readings to control system  1740 , which receives the pH readings and analyzes the information to determine if pH control is required. Where pH control is required, the control system  1740  sends a signal to instrumentation  1750  associated with tank  1710 . This information is received and processed by instrumentation  1750 , with the result being a desired amount of pH control process solution being sent to the tank  1420 . 
     In some embodiments, the tank  1420  may further include a mixer  1760  for mixing pH control process solution introduced into the tank with the electrolyte solution. In some embodiments, the mixing blade of the mixer  1760  may be located proximate the location where pH control process solution is introduced into the tank  1420 . 
       FIGS. 18A and 18B  illustrate an embodiment of a process line wherein a combination of various units disclosed herein are combined to carry out the electrodeposition of nanolaminate layers on a workpiece. In the process line shown in  FIGS. 18A and 18B , the workpiece enters the process line on the left and exits the process on the right. 
     The process line may begin with one or more pre-processing units which aim to put the workpiece in better condition for the electrodeposition process. In some embodiments, the first unit in the process line  1800  is an alkaline cleaner unit  1810 . The alkaline cleaner unit  1810  is similar to the plating cell shown in  FIGS. 1A and 1B . The alkaline unit  1810  does not include a cathode brush assembly or anode. Instead, the anode assembly is filled with the alkaline cleaner and the workpiece is passed through the anode assembly to carry out a cleaning step. 
     Next, the process line includes an electro-cleaner unit  1820 . The electro-cleaner unit  1820  is similar to the plating cell shown in  FIGS. 1A and 1B . In this case and as shown in  FIGS. 18A and 18B , the electro-cleaner unit  1820  includes the cathode brush assembly and the anode in the anode assembly so that electropolishing can be carried out on the workpiece to remove undesired material from the workpiece surface (e.g., material that may inhibit subsequent electrodeposition). Accordingly, a power source is provided for the electro-cleaner unit  1820  so that the workpiece (via the cathode brush assembly) and anode can be appropriately charged. 
     Following the electro-cleaner unit  1820 , a rinse unit  1830  is provided. As shown in  FIGS. 18A and 18B , the rinse unit  1830  includes three stages, although fewer or more stages can be used. Any rinse solution suitable for removing process solution used in the alkaline cleaner unit  1810  and the electro-cleaner unit  1820  can be used in the rinse unit  1830 . As also shown in  FIGS. 18A and 18B , the rinse unit  1830  may include a cathode brush assembly to help guide the workpiece through the rinse unit  1830  and provide a current to the workpiece as necessary. Accordingly, a power source may be provided for supplying a voltage to the cathode brush assembly in the rinse unit  1830 . 
     Following the rinse unit  1830 , a series of three acid activator units  1840  are provided. Three acid activator units  1840  are shown, but fewer or more acid activator units may be used as necessary. The acid activator units  1840  are similar to the alkaline cleaner unit  1810  in that the unit resembles the plating cell shown in  FIGS. 1A and 1B , but with the anode and cathode brush assembly removed. The workpiece passes through the anode assembly in each acid activator  1840 , which is filled with the process solution used for acid activation. Any material that is suitable for acid activation of the workpiece can be used in the acid activator cells  1840 . 
     Following the acid activator units  1840 , another rinse unit  1850  is provided. As shown in  FIGS. 18A and 18B , the rinse unit  1850  includes three stages, although fewer or more stages can be used. Any rinse solution suitable for removing process solution used in the acid activation units  1840  can be used in the rinse unit  1850 . As also shown in  FIGS. 18A and 18B , the rinse unit  1850  may include a cathode brush assembly to help guide the workpiece through the rinse unit  1850  and provide a current to the workpiece as necessary. Accordingly, a power source may be provided for supplying a voltage to the cathode brush assembly in the rinse unit  1850 . 
     Following the rinse unit  1850 , the workpiece passes through a plurality of plating cells  1860 . As shown in  FIGS. 18A and 18B , the process line includes 15 sequential plating cells through which the workpiece passes, although fewer or more plating cells can be used. Each plating cell is similar or identical to the plating cell shown in  FIGS. 1A and 1B . 
     Significantly, each plating cell  1860  may be operated independent of the other plating cells  1860 . Each plating cell may include its own power source which may be operated using different parameters than in other plating cells  1860  included in the process line  1800 . Each plating cell may include a different electrolyte solution. Each plating cell may use a different distance between the anode and the workpiece. Any other variable process parameter in the plating cell may be adjusted from one plating cell to another. In this manner, the process line may be used to carry out a variety of different coating procedures, including depositing coatings of different materials and thicknesses on the workpiece. 
     The various power supplies used for the plating cells may control the current density in a variety of ways including applying two or more, three or more or four or more different average current densities to the workpiece as it moves through the plating cell. In one embodiment, the power supply can control the current density in a time varying manner that includes applying an offset current, so that the workpiece remains cathodic when it is moved through the plating cell and the electrode remains anodic even though the potential between the workpiece and the electrode varies. In another embodiment, the power supply varies the current density in a time varying manner which comprises varying one or more of: the maximum current, baseline current, minimum current, frequency, pulse current modulation and reverse pulse current modulation. 
     Following the plating cells  1860 , the process line  1800  may include a rinse unit  1870 . The rinse unit  1870  shown in  FIGS. 18A and 18B  includes five stages (although fewer or more stages can be used). The rinse unit  1870  may be similar or identical to the rinse unit shown in  FIGS. 4A, 4B, and 16 . The rinse unit  1870  may be configured to deliver one or more different process solutions that are suitable for rinsing the workpiece of the process solutions use in the plating cells. In some embodiments, the first stage of the rinse unit provides a first rinse solution, the second and third stages provide a second rinse solution, and the fourth and fifth solutions provide a third rinse solution. The rinse unit  1870  may also include a cathode brush assembly. 
     Following the rinse unit  1870 , the process line  1800  may include various post processing units. In some embodiments, the rinse unit  1870  is followed by an acid activation unit  1880 . The acid activation unit may be similar or identical to the immersion unit  600  shown in  FIGS. 6A, 6B, and 16 . The acid activation unit  1880  includes an immersion vessel which is filled with process solution for carrying out acid activation. Any material suitable for carrying out acid activation on the work piece can be used. The workpiece passes through the immersion vessel, which prepares the workpiece for subsequent post processing steps. 
     Following the acid activation unit  1880 , the process line  1800  may include a chromate coating unit  1890 . The chromate coating unit  1890  may be similar to the acid activators  1840  used in the preprocessing portion of the process line  1800 . The chromate coating unit  1890  is therefore similar to the plating cell shown in  FIGS. 1A and 1B , but without the anode or cathode brush assembly. The anode assembly is filled with process solution for carrying out a chromate coating step, and the workpiece is passed through the anode assembly to expose the workpiece to the process solution. 
     Following the chromate coating unit  1890 , the process line may include a rinse unit  1900 . The rinse unit  1900  may be similar or identical to the rinse unit  1870 , including the use of five stages and multiple rinse solutions. In the rinse unit  1900 , the rinse solutions can be any rinse solutions suitable for rinsing the workpiece of process solutions used in the acid activation unit  1880  and the chromate coating unit  1890 . The rinse unit  1900  may include a cathode brush assembly to guide the workpiece and to provide a voltage if necessary/desired. 
     Following the rinse unit  1900 , the process line  1800  may include a forced air dryer  1910 . The forced air dryer  1910  may be similar or identical to the forced air dryer shown in  FIGS. 7A and 7B . The forced air dryer  1910  is used to dry the workpiece of the rinse solutions used in the rinse unit  1900 . 
     The workpiece may be moved through the process line  1800  using a strip puller  1920  provided at the end of the process line  1800 . The strip puller  1920  may be similar or identical to the strip puller shown in  FIGS. 8A and 8B . The strip puller  1920  may serve as a rate control mechanism which can adjust the speed at which the workpiece is pulled through the process line. 
     2.2 Alternate Electrodeposition Apparatus 
     The continuous application of nanolaminate coatings on conductive materials can also be accomplished using an electrodeposition apparatus as shown in  FIG. 19 . The electrodeposition apparatus can comprise:
         at least a first electrodeposition cell  1  through which a conductive workpiece  2 , which serves as an electrode in the cell, is moved at a rate,   a rate control mechanism that controls the rate the workpiece is moved through the electrodeposition cell;   an optional mixer for agitating electrolyte during the electrodeposition process (shown schematically in  FIG. 19  as item  3 );   a counter electrode  4 ; and   a power supply  8  controlling the current density applied to the workpiece in a time varying manner as it moves through the cell.       

     The rate control mechanism (throughput control mechanism) may be integral to one or more drive motors or the conveying system (e.g., rollers, wheels, pulleys, etc., of the apparatus), or housed in associated control equipment; accordingly, it is not shown in  FIG. 1 . Similarly the counter electrode may have a variety of configurations including, but not limited to, bars, plates, wires, baskets, rods, conformal anodes and the like, and accordingly is shown generically as a plate  4  at the bottom of the electrodeposition cell  1  in  FIG. 19 . The counter electrode, which functions as an anode except during reverse pulses, may be inert or may be active, in which case the anode will contain the metal species that is to be deposited and will dissolve into solution during operation. 
     Power supply  8  may control the current density in a variety of ways including applying two or more, three or more or four or more different average current densities to the workpiece as it moves through the electrodeposition cell(s). In one embodiment the power supply can control the current density in a time varying manner that includes applying an offset current, so that the workpiece remains cathodic when it is moved through the electrodeposition cell and the electrode remains anodic even though the potential between the workpiece and the electrode varies. In another embodiment the power supply varies the current density in a time varying manner which comprises varying one or more of: the maximum current, baseline current, minimum current, frequency, pulse current modulation and reverse pulse current modulation. 
     The workpiece may be introduced to the electrolyte by immersion in said electrolyte or by spray application of the electrolyte to the workpiece. The application of the electrolyte to the workpiece may be modulated. The rate by which the workpiece is moved through the electrolyte may also be modulated. 
     Mixing of electrolyte in the elecrodeposition cell is provided by solution circulation, a mechanical mixer and/or ultrasonic agitators. While bulk mixing can be provided by the mixer  3 , which can be controlled or configured to operate at variable speeds during the electrodeposition process, the apparatus may optionally include one or more ultrasonic agitators which are shown schematically as blocks  5  in the apparatus of  FIG. 19 . The ultrasonic agitators of the apparatus may be configured to operate independently in a continuous or in a non-continuous fashion (e.g., in a pulsed fashion). In one embodiment the ultrasonic agitators may operate at about 17,000 to 23,000 Hz. In another embodiment they may operate at about 20,000 Hz. Mixing of the electrolyte may also occur in a separate reservoir and the mixed electrolyte may contact the workpiece by immersion or by spray application. Instead of one or more salts of a metal to be electroplated, the electrolyte may comprise two or more, three or more or four or more different salts of electrodepositable metals. 
     The apparatus may include a location from which the workpiece material is supplied (e.g., a payoff reel) and a location where the coated workpiece is taken up (e.g., a take-up reel, which may be part of a strip puller for conveying a workpiece through the apparatus). Accordingly, the apparatus may comprise a first location  6 , from which the workpiece is moved to the electrodeposition cell and/or a second location  7  for receiving the workpiece after it has moved through the electrodeposition cell. Location  6  and location  7  are shown as spindles with reels in  FIG. 19 , however, they may also consist of racks for storing lengths of materials, folding apparatus, and even enclosures with one or more small openings, from which a workpiece (e.g., a wire, cable, strip or ribbon) is withdrawn or into which a coated workpiece is inserted. 
     In one embodiment the first and/or second location comprises a spool or a spindle. In such an embodiment the apparatus may be configured to electrodeposit a nanolaminate coating on a continuum of connected parts, wire, rod, sheet or tube that can be wound on the spool or around the spindle. 
     The apparatus may further comprise an aqueous or a non-aqueous electrolyte. The electrolyte may comprise salts of two or more, three or more or four or more electrodepositable metals. 
     In addition to the above-mentioned components, the apparatus may comprise one or more locations for treatment of the workpiece prior or subsequent to electrodeposition. In one embodiment the apparatus further includes one or more locations, between the first location and the electrodeposition cell, where the workpiece is contacted with one or more of: a solvent, an acid, a base, an etchant, and/or a rinsing agent to remove the solvent, acid, base, or etchant. In another embodiment the apparatus further includes one or more locations between the electrodeposition cell and a second location, where the coated workpiece is subject to one or more of: cleaning with solvent, cleaning with acid, cleaning with base, passivation treatments and rinsing. 
     3.0 Electrodeposition Process for the Continuous Application of Nanolaminated Coatings on Workpieces 
     The disclosure provided in this section is equally applicable to the apparatus and methods described in sections 2.1 and 2.2. 
     3.1 Workpieces 
     Workpieces may take a variety of forms or shapes. Workpieces may be, for example, in the form of wire, rod, tube, or sheet stock (e.g., rolls or folded sheets). Workpieces may be metal or other conductive strip, sheet or wire. Workpieces may also comprise a series of discrete parts that may be, for example, affixed to a sheet or webbing (e.g., metal netting or flexible screen) so as to form a sheet-like assembly that can be introduced into the electrodeposition cell in the same manner as substantially flat sheets that are to be coated with a nanolaminate by electrodeposition. Workpieces which are a series of discrete parts connected to form a strip must be connected by a conductive connector. 
     Virtually any material may be used as a workpiece, provided it can be rendered conductive and is not negatively affected by the electrolyte. The materials that may be employed as workpieces include, but are not limited to, metal, conductive polymers (e.g., polymers comprising polyaniline or polypyrrole), or non-conductive polymers rendered conductive by inclusion of conductive materials (e.g., metal powders, carbon black, graphene, graphite, carbon nanotubes, carbon nanofibers, or graphite fibers) or electroless application of a metal coating. 
     3.2 Continuous Electrodeposition of Nanolaminate Coatings 
     Nanolaminate coatings may be continuously electrodeposited by a method comprising:
         moving a workpiece through an apparatus comprising one or more electrodeposition cell(s) at a rate, where the electrodeposition cell(s) each comprise an electrode and an electrolyte comprising salts of one or more metals to be electrodeposited; and   controlling the mixing rate and/or the current density applied to the workpiece in a time varying manner as the workpiece moves through the cell(s), thereby electrodepositing a nanolaminate coating.       

     By controlling the current density applied to the workpiece in a time varying manner, nanolaminate coatings having layers varying in elemental composition and/or the microstructure of the electrodeposited material can be prepared. In one set of embodiments, controlling the current density in a time varying manner comprises applying two or more, three or more or four or more different current densities to the workpiece as it moves through the electrodeposition cell(s). In another embodiment, controlling the current density in a time varying manner includes applying an offset current, so that the workpiece remains cathodic when it is moved through the electrodeposition cell(s) and the electrode remains anodic, even though the potential between the workpiece and the electrode varies in time to produce nanolamination. In another embodiment controlling the current density in a time varying manner comprises varying one or more of: the baseline current, pulse current modulation and reverse pulse current modulation. 
     Nanolaminated coatings may also be formed on the workpiece as it passes through the electrodeposition cell(s) by controlling the mixing rate in a time varying manner. In one embodiment, controlling the mixing rate comprises agitating the electrolyte with a mixer (e.g., impeller or pump) at varying rates. In another embodiment, controlling the mixing rate comprises agitating the electrolyte by operating an ultrasonic agitator in a time varying manner (e.g., continuously, non-continuously, with a varying amplitude over time, or in a series of regular pulses of fixed amplitude). In another embodiment, controlling the mixing rate comprises pulsing a spray application of the electrolyte to the workpiece. 
     In another embodiment, the nanolaminate coatings may be formed by varying both the current density and the mixing rate simultaneously or alternately in the same electrodeposition process. 
     Regardless of which parameters are varied to induce nanolaminations in the coating applied to the workpiece as it is moved through the electrodeposition cell(s), the rate at which the workpiece passes through the cell(s) represents another parameter that can be controlled. In one embodiment rates that can be employed are in a range of about 1 to about 300 feet per minute. In other embodiments, the rates that can be employed are greater than about 1, 5, 10, 30, 50, 100, 150, 200, 250 or 300 feet per minute, or from about 1 to about 30 feet per minute, about 30 to about 100 feet per minute, about 100 to about 200 feet per minute, about 200 to about 300 feet per minute, or more than about 300 feet per minute. Faster rates will alter the time any portion of the workpiece being plated remains in the electrodeposition cell(s). Accordingly, the rate of mass transfer (rate of electrodeposition) that must be achieved to deposit the same nanolaminate coating thickness varies with the rate the workpiece is moved through the cell(s). In addition, where processes employ variations in current density to achieve nanolamination, the rate the variation in current density occurs must also be increased with an increasing rate of workpiece movement through the electrodeposition cell(s). 
     In one embodiment, the electrodeposition process may further include a step of moving the workpiece from a first location to the electrodeposition cell or a group of electrodeposition cell(s) (e.g., two or more, three or more, four or more, or five or more electrodeposition cells). In another embodiment, the electrodeposition process may further include a step of moving the workpiece from the electrodeposition cell or a group of electrodeposition cells to a second location for receiving the workpiece after electrodeposition of the nanolaminate coating. In such embodiments, the apparatus may have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or more electrodeposition cells that may each have separate power supplies for conducting electrodeposition in their respective cell. As such, the method may further comprise both moving the workpiece from a first location to the electrodeposition cell(s) and moving the workpiece from the electrodeposition cell to the second location. 
     3.3 Nanolaminate and Fine Grain Coating and Electrolyte Compositions for their Electrodeposition 
     Continuous electrodeposition of nanolaminate coatings can be conducted from either aqueous or non-aqueous electrolytes comprising salts of the metals to be electrodeposited. 
     In one embodiment, electrodepositing a nanolaminate coating comprises the electrodeposition of a layered composition comprising one or more, two or more, three or more or four or more different elements independently selected from Ag, Al, Au, Be, Co, Cr, Cu, Fe, Hg, In, Mg, Mn, Mo, Nb, Nd, Ni, P, Pd, Pt, Re, Rh, Sb, Sn, Pb, Ta, Ti, W, V, Zn and Zr, wherein each of said independently selected metals is present at greater than about 0.1, about 0.05, about 0.01, about 0.005 or about 0.001% by weight. In one such embodiment, electrodepositing a nanolaminate coating comprises electrodeposition of a layered composition comprising two or more different elements independently selected from Ag, Al, Au, Be, Co, Cr, Cu, Fe, Hg, In, Mg, Mn, Mo, Nb, Nd, Ni, P, Pd, Pt, Re, Rh, Sb, Sn, Pb, Ta, Ti, W, V, Zn and Zr, wherein each of said independently selected metals is present at greater than about 0.005 or about 0.001% by weight. In another such embodiment, electrodepositing a nanolaminate coating comprises the electrodeposition of layers comprising two or more different metals, where the two or more different metals comprise: Zn and Fe, Zn and Ni, Co and Ni, Ni and Fe, Ni and Cr, Ni and Al, Cu and Zn, Cu and Sn, or a composition comprising Al and Ni and Co (AlNiCo). In any of those embodiments the nanolaminate coating may comprise at least one portion consisting of a plurality of layers, wherein each of said layers has a thickness in a range selected independently from: about 5 nm to about 250 nm, from about 5 nm to about 25 nm, from about 10 nm to about 30 nm, from about 30 nm to about 60 nm, from about 40 nm to about 80 nm, from about 75 nm to about 100 nm, from about 100 nm to about 120 nm, from about 120 nm to about 140 nm, from about 140 nm to about 180 nm, from about 180 nm to about 200 nm, from about 200 nm to about 225 nm, from about 220 nm to about 250 nm, or from about 150 nm to about 250 nm. 
     In another embodiment, the electrodeposited nanolaminate coating compositions comprise a plurality of first layers and second layers that differ in structure or composition. The first layers and second layers may have discrete or diffuse interfaces at the boundary between the layers. In addition, the first and second layers may be arranged as alternating first and second layers. 
     In embodiments where the electrodeposited nanolaminate coatings comprise a plurality of alternating first layers and second layers, those layers may comprise two or more, three or more, four or more, six or more, eight or more, ten or more, twenty or more, forty or more, fifty or more, 100 or more, 200 or more, 500 or more, 1,000 or more, 1,500 or more, 2,000 or more, 3,000 or more, 5,000 or more or 8,000 or more alternating first and second layers independently selected for each multilayer coating. 
     In one embodiment each first layer and each second layer comprises, consists essentially of, or consists of two, three, four or more elements independently selected from: Ag, Al, Au, Be, Co, Cr, Cu, Fe, Hg, In, Mg, Mn, Mo, Nb, Nd, Ni, P, Pd, Pt, Re, Rh, Sb, Sn, Pb, Ta, Ti, W, V, Zn and Zr. In another embodiment, each first layer and each second layer comprises, consists essentially of, or consists of two, three, four or more elements independently selected from: Ag, Al, Au, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Sb, Sn, Mn, Pb, Ta, Ti, W, V, and Zn. In another embodiment, each first layer and each second layer comprises, consists essentially of, or consists of two, three, four or more elements independently selected from: Al, Au, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Sn, Mn, Ti, W, V, and Zn. 
     In one embodiment each first layer comprises nickel in a range independently selected from about 1% to about 5%, about 5% to about 7%, about 7% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 30%, about 30% to about 40%, about 40% to about 50%, about 50% to about 55%, about 55% to about 60%, about 60% to about 65%, about 65% to about 70%, about 70% to about 75%, about 75% to about 80%, about 80% to about 85%, about 85% to about 90%, about 90% to about 92%, about 92% to about 93%, about 93% to about 94%, about 94% to about 95%, about 95% to about 96%, about 96% to about 97%, about 97% to about 98% or about 98% to about 99%. In such an embodiment, each second layer may comprise cobalt and/or chromium in a range independently selected from about 1% to about 35%, about 1% to about 3%, about 2% to about 5%, about 5% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 25%, about 25% to about 30% or about 30% to about 35%. 
     In one embodiment each first layer comprises nickel in a range independently selected from about 1% to about 5%, about 5% to about 7%, about 7% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 30%, about 30% to about 40%, about 40% to about 50%, about 50% to about 55%, about 55% to about 60%, about 60% to about 65%, about 65% to about 70%, about 70% to about 75%, about 75% to about 80%, about 80% to about 85%, about 85% to about 90%, about 90% to about 92%, about 92% to about 93%, about 93% to about 94%, about 94% to about 95%, about 95% to about 96%, about 96% to about 97%, about 97% to about 98% or about 98% to about 99%, and the balance of the layer comprises cobalt and/or chromium. In such an embodiment, each second layer may comprise cobalt and/or chromium in a range selected independently from about 1% to about 35%, about 1% to about 3%, about 2% to about 5%, about 5% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 25%, about 25% to about 30% or about 30% to about 35%, and the balance of the layer comprises nickel. In such embodiments, first and second layers may additionally comprise aluminum. 
     In one embodiment each first layer comprises nickel in a range independently selected from about 1% to about 5%, about 5% to about 7%, about 7% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 30%, about 30% to about 40%, about 40% to about 50%, about 50% to about 55%, about 55% to about 60%, about 60% to about 65%, about 65% to about 70%, about 70% to about 75%, about 75% to about 80%, about 80% to about 85%, about 85% to about 90%, about 90% to about 92%, about 92% to about 93%, about 93% to about 94%, about 94% to about 95%, about 95% to about 96%, about 96% to about 97%, about 97% to about 98% or about 98% to about 99%, and the balance of the layer comprises aluminum. In such an embodiment, each second layer may comprise aluminum in a range selected independently from about 1% to about 35%, about 1% to about 3%, about 2% to about 5%, about 5% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 25%, about 25% to about 30% or about 30% to about 35%, and the balance of the layer comprises nickel. 
     In one embodiment each first layer comprises nickel in a range independently selected from about 1% to about 5%, about 5% to about 7%, about 7% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 30%, about 30% to about 40%, about 40% to about 50%, about 50% to about 55%, about 55% to about 60%, about 60% to about 65%, about 65% to about 70%, about 70% to about 75%, about 75% to about 80%, about 80% to about 85%, about 85% to about 90%, about 90% to about 92%, about 92% to about 93%, about 93% to about 94%, about 94% to about 95%, about 95% to about 96%, about 96% to about 97%, about 97% to about 98% or about 98% to about 99%, and the balance of the layer comprises iron. In such an embodiment, each second layer may comprise iron in a range independently selected from about 1% to about 35%, about 1% to about 3%, about 2% to about 5%, about 5% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 25%, about 25% to about 30% or about 30% to about 35%, and the balance of the layer comprises nickel. 
     In one embodiment each first layer comprises zinc in a range independently selected from about 1% to about 5%, about 5% to about 7%, about 7% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 30%, about 30% to about 40%, about 40% to about 50%, about 50% to about 55%, about 55% to about 60%, about 60% to about 65%, about 65% to about 70%, about 70% to about 75%, about 75% to about 80%, about 80% to about 85%, about 85% to about 90%, about 90% to about 92%, about 92% to about 93%, about 93% to about 94%, about 94% to about 95%, about 95% to about 96%, about 96% to about 9′7%, about 9′7% to about 98%, about 98% to about 99%, about 99% to about 99.5%, about 99.2% to about 99.7%, or about 99.5% to about 99.99%, and the balance of the layer comprises iron. In such an embodiment, each second layer may comprise iron in a range independently selected from about 0.01% to about 35%, about 0.01% to about 0.5%, about 0.3% to about 0.8%, about 0.5% to about 1.0%, about 1% to about 3%, about 2% to about 5%, about 5% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 25%, about 25% to about 30% or about 30% to about 35%, and the balance of the layer comprises zinc. 
     In any of the foregoing embodiments the first and/or second layers may each comprise one or more, two or more, three or more, or four or more elements selected independently for each first and second layer from the group consisting of Ag, Al, Au, Be, Co, Cr, Cu, Fe, Hg, In, Mg, Mn, Mo, Nb, Nd, Ni, P, Pd, Pt, Re, Rh, Sb, Sn, Pb, Ta, Ti, W, V, Zn and Zr. 
     In one embodiment, electrodepositing a “fine-grained” or “ultrafine-grained” metal comprises electrodepositing a metal or metal alloy having an average grain size from 1 nm to 5,000 nm (e.g., 1-20, 1-100, 5-50, 5-100, 5-200, 10-100, 10-200, 20-200, 20-250, 20-500, 50-250, 50-500, 100-500, 200-1,000, 500-2,000, or 1,000-5,000 nm based on the measurement of grain size in micrographs). In such embodiments, the fine-grained metal or alloy may comprise one or more, two or more, three or more, or four or more elements selected independently from the group consisting of Ag, Al, Au, Be, Co, Cr, Cu, Fe, Hg, In, Mg, Mn, Mo, Nb, Nd, Ni, P, Pd, Pt, Re, Rh, Sb, Sn, Pb, Ta, Ti, W, V, Zn and Zr. Fine-grained metals and alloys, including those comprising a high degree of twinning between metal grains, may remain ductile while having one or more properties including increased hardness, tensile strength, and corrosion resistance relative to electrodeposited metals or alloys of the same composition with a grain size from 5,000 to 20,000 nm or greater. 
     In one embodiment, the coefficient of thermal expansion of the nanolaminate coating layers and/or the fine grain coating layers is within 20% (less than 20%, 15%. 10%, 5%, or 2%) of the workpiece in the direction parallel to workpiece movement (i.e., in the plane of the workpiece and parallel to the direction of workpiece movement). 
     3.4 Pre- and Post-Electrodeposition Treatments 
     Prior to electrodeposition, or following electrodeposition, methods of continuously electrodepositing a nanolaminate coating may include further steps of pre-electrodeposition or post-electrodeposition treatment. 
     Accordingly, the apparatus described above may further comprise one or more locations between the first location and the electrodeposition cell(s), and the method may further comprise contacting the workpiece with one or more of: a solvent, an acid, a base, an etchant, or a rinsing solution (e.g., water) to remove said solvent, acid, base, or etchant. In addition, the apparatus described above may further comprise one or more locations between the electrodeposition cell(s) and a second location, and the method may further comprise contacting the workpiece with one or more of: a solvent, an acid, a base, a passivation agent, or a rinse solution (e.g., water) to remove the solvent, acid, base or passivation agent. 
     4.0 Nanolaminated Articles Prepared by Continuous Electrodeposition 
     The disclosure provided in this section is equally applicable to the apparatus and methods described in sections 2.1 and 2.2 
     The process and apparatus described herein may be adapted for the preparation of articles comprising, consisting essentially of, or consisting of nanolaminated materials by the use of a workpiece to which the coating applied during electrodeposition does not adhere tightly. The article may be obtained after removal of the workpiece from the electrodeposition process by separating the coating from the workpiece. In addition, where the workpiece is not flat, 3-dimensional articles may be formed as reliefs on the contoured surface of the workpiece. 
     5.0 Certain Embodiments 
     1. An apparatus for electrodepositing a nanolaminate coating comprising: 
     at least a first electrodeposition cell and a second electrodeposition cell (e.g., two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen fifteen, sixteen or more electrodeposition cells) through which a conductive workpiece is moved at a rate, each electrodeposition cell containing an electrode (e.g., an anode); and 
     a rate control mechanism that controls the rate the workpiece is moved through the electrodeposition cell(s); wherein each electrodeposition cell optionally comprises a mixer for agitating an electrolyte in its respective electrodeposition cell during the electrodeposition process; 
     wherein each electrodeposition cell optionally comprises a flow control unit for applying an electrolyte to the workpiece; and 
     wherein each electrodeposition cell has a power supply (e.g., a power supply for each cell or groups of cells comprising two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen or fifteen cells) controlling the current density and/or voltage applied to the workpiece in a time varying manner as it moves through each electrodeposition cell. 
     2. The apparatus of embodiment 1, wherein controlling the current density in a time varying manner comprises applying two or more, three or more or four or more different current densities to the workpiece as it moves through at least one electrodeposition cell (e.g., two or more, three or more, four or more, five or more, or each electrodeposition cell).
 
3. The apparatus of embodiment 2, wherein controlling the current density in a time varying manner comprises applying an offset current, so that the workpiece remains cathodic when it is moved through at least one electrodeposition cell (e.g., one or more, two or more, three or more, four or more, five or more, or each electrodeposition cell) and the electrode remains anodic.
 
4. The apparatus of any of embodiments 1 or 2, wherein the time varying manner comprises one or more of: varying the baseline current, pulse current modulation and reverse pulse current modulation.
 
5. The apparatus of any of the preceding embodiments, wherein one or more of the electrodeposition cells further comprises an ultrasonic agitator.
 
6. The apparatus of embodiment 5, wherein each ultrasonic agitator independently operates continuously or in a pulsed fashion.
 
7. The apparatus of any of the preceding embodiments, wherein at least one electrodeposition cell (e.g., one or more, two or more, three or more, four or more, five or more, or each electrodeposition cell) comprises a mixer that operates independently to variably mix an electrolyte placed in its respective electrodeposition cell(s).
 
8. The apparatus of any of the preceding embodiments, further comprising a first location, from which the workpiece is moved to the electrodeposition cells, and/or a second location, for receiving the workpiece after it has moved through one or more of the electrodeposition cells.
 
9. The apparatus of embodiment 8, wherein the first and/or second location comprises a spool or a spindle.
 
10. The apparatus of embodiment 9, wherein the workpiece is a wire, rod, sheet, chain, strand, or tube that can be wound on said spool or around said spindle.
 
11. The apparatus of any of the preceding embodiments, wherein any one or more of said electrodeposition cell(s) (e.g., one or more, two or more, three or more, four or more, five or more, or each electrodeposition cell) comprises (contains) an aqueous electrolyte.
 
12. The apparatus of any of embodiments 1-10, wherein any one or more of said electrodeposition cell(s) (e.g., one or more, two or more, three or more, four or more, five or more, or each electrodeposition cell) comprises (contains) a non-aqueous electrolyte.
 
13. The apparatus of any preceding embodiment, wherein each electrolytes comprises salts of two or more, three or more or four or more electrodepositable metals, which are selected independently for each electrolyte.
 
14. The apparatus of any of the preceding embodiments further comprising one or more locations between the first location and the electrodeposition cells, where the workpiece is contacted with one or more of: a solvent, an acid, a base, an etchant, and a rinsing agent to remove said solvent, acid, base, or etchant.
 
15. The apparatus of any of the preceding embodiments further comprising one or more locations between the electrodeposition cells and said second location, where the coated workpiece is subject to one or more of: cleaning with solvent, cleaning with acid, cleaning with base, passivation treatments, or rinsing.
 
16. A method of electrodepositing a nanolaminate coating comprising:
 
     providing an apparatus comprising at least a first electrodeposition cell and a second electrodeposition cell (e.g., two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or more electrodeposition cells); 
     wherein each electrodeposition cell has a power supply (e.g., a power supply for each cell or groups of cells comprising two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen or fifteen cells) controlling the current density applied to the workpiece in a time varying manner as it moves through each electrodeposition cell; 
     where each electrodeposition cell comprises an electrode and an electrolyte comprising salts of two or more, three or more, or four or more different electrodepositable metals selected independently for each electrolyte; and 
     moving a workpiece through at least the first electrodeposition cell and the second electrodeposition cell of the apparatus at a rate and independently controlling the mixing rate and/or the current density applied to the workpiece in a time varying manner as it moves through each electrodeposition cell, thereby electrodepositing a coating comprising nanolaminate coating layers and/or one or more (e.g., two or more, three or more, four or more, or five or more) fine-grained metal layers. 
     17. The method of embodiment 16, wherein controlling the current density in a time varying manner comprises applying two or more, three or more, or four or more different current densities to the workpiece as it moves through at least one electrodeposition cell (e.g., two or more, three or more, four or more, or five or more electrodeposition cells).
 
18. The method of embodiment 16 or 17, wherein controlling the current density in a time varying manner comprises applying an offset current, so that the workpiece remains cathodic when it is moved through at least one electrodeposition cell (e.g., two or more, three or more, four or more, or five or more electrodeposition cells) and the electrode remains anodic.
 
19. The method of embodiments 16 or 17, wherein the time varying manner comprises one or more of: varying the baseline current, pulse current modulation and reverse pulse current modulation.
 
20. The method of any of embodiments 16-19, wherein one or more electrodeposition cells comprises a mixer, wherein each mixer is independently operated at a single rate or at varying rates to agitate the electrolyte within its respective electrodeposition cell.
 
21. The method of any of embodiments 16-20, wherein one or more electrodeposition cells comprises an ultrasonic agitator, wherein each agitator is independently operated continuously or in a non-continuous fashion to control the mixing rate.
 
22. The method of any of embodiments 16-21, further comprising controlling the rate the workpiece is moved through the electrodeposition cells.
 
23. The method of any of embodiments 16-22, wherein the apparatus further comprises a first location, from which the workpiece is moved to the first electrodeposition cell and the second electrodeposition cell (e.g., the electrodeposition cells), and/or a second location for receiving the workpiece after it has moved through the first electrodeposition cell and the second electrodeposition cell (e.g., the electrodeposition cells), the method further comprising moving the workpiece from the first location to the first electrodeposition cell and the second electrodeposition cell and/or moving the workpiece from the first electrodeposition cell and the second electrodeposition cell to the second location.
 
24. The method of embodiment 23, wherein the apparatus further comprises one or more locations between the first location and the electrodeposition cell(s), and the method further comprises contacting the workpiece with one or more of: a solvent, an acid, a base, and an etchant, and rinsing to remove said solvent, acid, base, or etchant at one or more of the locations between the first location and the electrodeposition cell(s).
 
25. The method of embodiments 23 or 24, wherein the apparatus further comprises one or more locations between the electrodeposition cells and said second location, and the method further comprises contacting the workpiece with one or more of: a solvent, an acid, a base, a passivation agent, and a rinsing agent to remove the solvent, acid, base and/or passivation agent at one or more locations between the electrodeposition cells and said second location.
 
26. The method of any of embodiments 16-25, wherein said workpiece is comprised of a metal, a conductive polymer or a non-conductive polymer rendered conductive by inclusion of conductive materials or electroless application of a metal.
 
27. The method of any of embodiments 16-26, wherein the workpiece is a wire, rod, sheet, chain, strand, or tube.
 
28. The method of any of embodiments 16-27, wherein the electrolytes is/are aqueous electrolyte(s) (e.g., one or more, two or more, or each electrolyte is an aqueous electrolyte).
 
29. The method of any of embodiments 16-27, wherein the electrolyte(s) is/are a non-aqueous electrolyte(s) (e.g., one or more, two or more, or each electrolyte is a non-aqueous electrolyte).
 
30. The method of any of embodiments 16-29, wherein electrodepositing a nanolaminate coating or fine grained metal comprises the electrodeposition of a composition comprising one or more, two or more, three or more or four or more different elements independently selected from Ag, Al, Au, Be, Co, Cr, Cu, Fe, Hg, In, Mg, Mn, Mo, Nb, Nd, Ni, P, Pd, Pt, Re, Rh, Sb, Sn, Pb, Ta, Ti, W, V, Zn and Zr, wherein each of said independently selected metals is present at greater than 0.1, 0.05, 0.01, 0.005 or 0.001% by weight.
 
31. The method of any of embodiments 16-29, wherein electrodepositing a nanolaminate coating or fine grained metal comprises the electrodeposition of a composition comprising two or more different elements independently selected from Ag, Al, Au, Be, Co, Cr, Cu, Fe, Hg, In, Mg, Mn, Mo, Nb, Nd, Ni, P, Pd, Pt, Re, Rh, Sb, Sn, Pb, Ta, Ti, W, V, Zn and Zr, wherein each of said independently selected metals is present at greater than about 0.1, 0.05, 0.01, 0.005 or 0.001% by weight.
 
32. The method of embodiment 31, wherein said two or more different metals comprise: Zn and Fe, Zn and Ni, Co and Ni, Ni and Fe, Ni and Cr, Ni and Al, Cu and Zn, Cu and Sn, or a composition comprising Al and Ni and Co.
 
33. The method according to any of embodiments 16-32, wherein the nanolaminate coating comprises at least one portion consisting of a plurality of layers, wherein each of said layers has a thickness in a range selected independently from about 5 nm to about 250 nm, from about 5 nm to about 25 nm, from about 10 nm to about 30 nm, from about 30 nm to about 60 nm, from about 40 nm to about 80 nm, from about 75 nm to about 100 nm, from about 100 nm to about 120 nm, from about 120 nm to about 140 nm, from about 140 nm to about 180 nm, from about 180 nm to about 200 nm, from about 200 nm to about 225 nm, from about 220 nm to about 250 nm, or from about 150 nm to about 250 nm.
 
34. The method of any of embodiments 16-33, wherein the nanolaminate coating layers comprise a plurality of first layers and second layers that differ in structure or composition, and which may have discrete or diffuse interfaces between the first and second layers.
 
35. The method of embodiment 34, wherein the first and second layers are arranged as alternating first and second layers.
 
36. The method of embodiment 35, wherein said plurality of alternating first layers and second layers comprises two or more, three or more, four or more, six or more, eight or more, ten or more, twenty or more, forty or more, fifty or more, 100 or more, 200 or more, 500 or more, 1,000 or more, 1,500 or more, 2,000 or more, 4,000 or more, 6,000 or more, or 8,000 or more alternating first and second layers independently selected for each multilayer coating.
 
37. The method of any of embodiments 34-36, wherein each first layer comprises nickel in a range independently selected from 1%-5%, 5%-7%, 7%-10%, 10%-15%, 15%-20%, 20%-30%, 30%-40%, 40%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 70%-75%, 75%-80%, 80%-85%, 85%-90%, 90%-92%, 92%-93%, 93%-94%, 94%-95%, 95%-96%, 96%-97%, 97%-98% or 98%-99%.
 
38. The method of embodiment 37, wherein each second layer comprises cobalt and/or chromium in a range independently selected from 1%-35%, 1%-3%, 2%-5%, 5%-10%, 10%-15%, 15%-20%, 20%-25%, 25%-30% or 30%-35%.
 
39. The method of any of embodiments 34-36, wherein each first layer comprises nickel in a range independently selected from 1%-5%, 5%-7%, 7%-10%, 10%-15%, 15%-20%, 20%-30%, 30%-40%, 40%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 70%-75%, 75%-80%, 80%-85%, 85%-90%, 90%-92%, 92%-93%, 93%-94%, 94%-95%, 95%-96%, 96%-97%, 97%-98% or 98%-99%, and the balance of the layer comprises, consists essentially of, or consists of cobalt and/or chromium.
 
40. The method of embodiment 39, wherein each second layer comprises cobalt and/or chromium in a range selected independently from 1%-35%, 1%-3%, 2%-5%, 5%-10%, 10%-15%, 15%-20%, 20%-25%, 25%-30% or 30%-35%, and the balance of the layer comprises, consists essentially of, or consists of nickel.
 
41. The method of any of embodiments 34-36, wherein each first layer comprises nickel in a range independently selected from 1%-5%, 5%-7%, 7%-10%, 10%-15%, 15%-20%, 20%-30%, 30%-40%, 40%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 70%-75%, 75%-80%, 80%-85%, 85%-90%, 90%-92%, 92%-93%, 93%-94%, 94%-95%, 95%-96%, 96%-97%, 97%-98% or 98%-99%, and the balance of the layer comprises, consists essentially of, or consists of iron.
 
42. The method of embodiment 41, wherein each second layer comprises iron in a range independently selected from 1%-35%, 1%-3%, 2%-5%, 5%-10%, 10%-15%, 15%-20%, 20%-25%, 25%-30% or 30%-35%, and the balance of the layer comprises, consists essentially of, or consists of nickel.
 
43. The method of any of embodiments 34-36, wherein each first layer comprises zinc in a range independently selected from 1%-5%, 5%-7%, 7%-10%, 10%-15%, 15%-20%, 20%-30%, 30%-40%, 40%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 70%-75%, 75%-80%, 80%-85%, 85%-90%, 90%-92%, 92%-93%, 93%-94%, 94%-95%, 95%-96%, 96%-97%, 97%-98%, 98%-99%, 99%-99.5%, 99.2%-99.7%, or 99.5%-99.99%, and the balance of the layer comprises, consists essentially of, or consists of iron.
 
44. The method of embodiment 43, wherein each second layer comprises iron in a range independently selected from 0.01%-35%, 0.01%-0.5%, 0.3%-0.8%, 0.5%-1.0%, 1%-3%, 2%-5%, 5%-10%, 10%-15%, 15%-20%, 20%-25%, 25%-30% or 30%-35%, and the balance of the layer comprises, consists essentially of, or consists of zinc.
 
45. The method of any of embodiments 34-36, wherein one or more of said first and/or second layers comprises one or more, two or more, three or more or four or more elements selected independently for each first and second layer from the group consisting of Ag, Al, Au, C, Cr, Cu, Fe, Mg, Mn, Mo, Sb, Si, Sn, Pb, Ta, Ti, W, V, Zn and Zr.
 
46. A product produced by the method of any of embodiments 16-45.