Surface attrition treatment, compositions, and methods of use thereof

Abstract

The present invention relates to surface attrition treatment, compositions, and methods of use thereof.

What is claimed is: 
     
         1 . A method of producing a gradient nano-grained surface layer on an alloy comprising:
 obtaining a milling media and a base alloy;   coating the milling media in a powder; and   subjecting the base alloy to surface mechanical attrition treatment (SMAT) by impacting the alloy with the coated milling media to generate a SMAT alloy with a gradient nano-grained surface layer.   
     
     
         2 . The method of  claim 1 , wherein the base alloy is subjected to heat treatment or is not subjected to heat treatment. 
     
     
         3 . The method of  claim 2 , wherein the heat treatment comprises solutionization, aging treatment, or a combination thereof. 
     
     
         4 . The method of  claim 2 , wherein the alloy is subjected to heat treatment before SMAT, subjected to heat treatment after SMAT, or subjected to heat treatment both before and after SMAT. 
     
     
         5 . The method of  claim 1 , wherein the milling media comprises stainless steel. 
     
     
         6 . The method of  claim 5 , wherein the stainless steel comprises 440C stainless steel. 
     
     
         7 . The method of  claim 1 , wherein the base alloy comprises an aluminum alloy. 
     
     
         8 . The method of  claim 7 , wherein the base alloy comprises 7075 aluminum alloy, 2024 aluminium alloy, 5083 aluminium alloy, and 6061 aluminium alloy. 
     
     
         9 . The method of  claim 1 , wherein the powder comprises elements which do not induce more cathodic precipitates. 
     
     
         10 . The method of  claim 7 , wherein the powder comprises a metal found in the base alloy. 
     
     
         11 . The method of  claim 8 , wherein the metal comprises aluminum. 
     
     
         12 . The method of  claim 1 , wherein the powder comprises a metal not found in the base alloy, a metal found in the base alloy, an element, a combination of elements, a ceramic powder, carbide, or combination thereof. 
     
     
         13 . The method of  claim 12 , wherein the metal comprises aluminum, magnesium, magnesium, copper, iron, chromium, titanium, zinc, scandium, vanadium, cobalt, nickel, silicon, or a combination thereof. 
     
     
         14 . The method of  claim 1 , wherein the surface mechanical attrition treatment (SMAT) is performed at room temperature or liquid-nitrogen (LN 2 ) cooled temperature. 
     
     
         15 . The method of any one of  claims 1 - 14 , wherein the SMAT alloy has improved corrosion resistance compared to the base alloy. 
     
     
         16 . The method of any one of  claims 1 - 14 , wherein the SMAT alloy has improved surface resistance compared to the base alloy. 
     
     
         17 . The method of any one of  claims 1 - 11  or  14 - 16 , wherein the elemental components of the SMAT alloy are not changed compared to the base alloy. 
     
     
         18 . A SMAT alloy produced by the method of any one of  claims 1 - 17 . 
     
     
         19 . The SMAT alloy of  claim 18 , wherein the SMAT alloy has improved corrosion resistance compared to an untreated alloy. 
     
     
         20 . The SMAT alloy of  claim 18 , wherein the SMAT alloy has improved surface resistance compared to an untreated alloy. 
     
     
         21 . The SMAT alloy of  claim 18 , wherein the SMAT alloy has a higher thickness of oxide layer compared to an untreated alloy when exposed to a corrosive agent.