Articles from microarc processes and methods of manufacturing same

Abstract

Disclosed articles as results of a microarc oxidation process, or plurality thereof, which are not limited by size, specifically by certain dimensions of their size, such as their length. Different sections or surfaces of articles of the invention may be subjected to a microarc oxidation process at any given time, such as by gradually subjecting a surface of an article to a microarc oxidation process, or such as by sequentially subjecting different sections of an articles to a microarc oxidation process. Further-more, disclosed are methods for manufacturing of articles of the invention, or otherwise for subjecting articles of the invention to a microarc oxidation process, or plurality thereof. In some examples, tubes of above 6 meter in length may be coated according to methods of the invention. The coating of said tubes may be beneficial for desalination applications. In other examples, only grooves of pulleys are coated. Further disclosed are articles which underwent a microarc oxidation process, or plurality thereof, which included different solution, optionally by utilizing a solution modulator.

1 . A method of providing plasma electrolytic oxide coating to a valve metal article, comprising the steps of:
 a) exposing a first section of the entire surface area of said valve metal article to an electrolyte by at least one of i) inserting the first section into a first electrolyte bath and ii) inserting a second electrolyte bath inside said valve metal article;   b) inducing a first localized plasma reaction;   c) extracting at least a part of said first section of the entire surface area from said electrolyte and exposing a second section of the entire surface area of said valve metal article to said electrolyte by at least one of i) removing at least a part of the first section from the first electrolyte bath and inserting at least a part of the second section into the first electrolyte bath and ii) moving the second electrolyte bath inside said metal valve article; and   d) inducing a second localized plasma reaction on the exposed second section.   
     
     
         2 . The method of  claim 1 , wherein said exposing of said second section is sequential to said exposing of said first section. 
     
     
         3 . The method of  claim 2 , wherein there is no time in between the first and the second localized plasma reactions. 
     
     
         4 . The method of  claim 1 , wherein said first section and said second section have the same length. 
     
     
         5 . The method of  claim 1 , wherein said first section and said second section have the same surface area. 
     
     
         6 . The method of  claim 1 , wherein said first section and said second section have a common area. 
     
     
         7 . The method of  claim 1 , wherein the structure comprises end panels which form the closed space together with the first section during induction of the first localized plasma reaction. 
     
     
         8 . The method of  claim 1 , further comprising adding new solution into the first and/or second electrolyte bath through a first pipe and draining used solution from the first and/or second electrolyte bath through a second pipe. 
     
     
         9 . The method of  claim 8 , further comprising altering the first and/or second electrolyte bath between the first and the second localized plasma reactions by adding and/or removing a solvent and/or solute via a solution modulator. 
     
     
         10 . The method of  claim 9 , further comprising obtaining information about the first and/or second electrolyte bath via a monitor of the solution modulator and at least one of: adjusting temperature of the first and/or second electrolyte bath, adjusting pH of the first and/or second electrolyte bath, and adding a substance to the first and/or second electrolyte bath via the solution modulator. 
     
     
         11 . The method of  claim 1 , wherein exposing the first section to the electrolyte comprises inserting the valve metal article into a container containing the first electrolyte bath and wherein extracting at least a part of said first section from said electrolyte comprises inserting the valve metal article further into the container such that a part of said first section of the valve metal article emerges out of the container. 
     
     
         12 . The method of  claim 1 , wherein the container comprises a first side port into which the valve metal article is inserted from outside the container, the first side port pressing against an outer surface of said valve metal article after insertion and forming a first seal preventing leakage of the first electrolyte bath, and a second side port into which the valve metal article is inserted from inside the container, the second side port pressing against an outer surface of said valve metal article after insertion and forming a seal preventing leakage of the first electrolyte bath. 
     
     
         13 . The method of  claim 1 , wherein the valve metal article is a tube. 
     
     
         14 . A method of providing plasma electrolytic oxide coating to a valve metal article, comprising the steps of:
 a) exposing a first section of the entire surface area of said valve metal article to an electrolyte by at least one of i) inserting the first section into a first electrolyte bath and ii) inserting a second electrolyte bath inside said valve metal article;   b) inducing a first localized plasma reaction;   c) extracting at least a portion of said first section of the entire surface area from said electrolyte and exposing a second section of the entire surface area of said valve metal article to said electrolyte by at least one of i) removing at least a portion of the first section from the first electrolyte bath and inserting at least a portion of the second section into the first electrolyte bath and ii) moving the second electrolyte bath inside said metal valve article; and   d) inducing a second localized plasma reaction on the exposed second section;   wherein exposing the first section to the electrolyte comprises inserting a structure inside said valve metal article that, in combination with the valve metal article, forms a closed space holding the second electrolyte bath inside said valve metal article and wherein extracting at least a portion of said first section from said electrolyte comprises moving the closed space holding the second electrolyte bath inside said valve metal article.   
     
     
         15 . The method of  claim 14 , wherein the valve metal article is a tube. 
     
     
         16 . A method of providing plasma electrolytic oxide coating to a valve metal article, comprising the steps of:
 a) exposing a first section of the entire surface area of said valve metal article to an electrolyte by at least one of i) inserting the first section into a first electrolyte bath and ii) inserting a second electrolyte bath inside said valve metal article;   b) inducing a first localized plasma reaction;   c) extracting at least a portion of said first section of the entire surface area from said electrolyte and exposing a second section of the entire surface area of said valve metal article to said electrolyte by at least one of i) removing at least a portion of the first section from the first electrolyte bath and inserting at least a portion of the second section into the first electrolyte bath and ii) moving the second electrolyte bath inside said metal valve article; and   d) inducing a second localized plasma reaction on the exposed second section;   wherein exposing the first section to the electrolyte comprises rotating the valve metal article about an axis and wherein extracting at least a portion of said first section from said electrolyte comprises rotating the valve metal article about the axis.