US 9,809,893 B2
Surface mechanical attrition treatment (SMAT) methods and systems for modifying nanostructures
Christohper Michael Lee, Kowloon (HK); Yang Yang Li, Kowloon (HK); and Jian Lu, Kowloon (HK)
Assigned to CITY UNIVERSITY OF HONG KONG, Kowloon (HK)
Filed by City University of Hong Kong, Kowloon (HK)
Filed on Feb. 26, 2015, as Appl. No. 14/632,864.
Prior Publication US 2016/0250773 A1, Sep. 1, 2016
Int. Cl. B06B 1/10 (2006.01); C25D 11/00 (2006.01); C25D 11/26 (2006.01); C23C 18/16 (2006.01); C23C 16/56 (2006.01); C23C 16/44 (2006.01)
CPC C25D 11/005 (2013.01) [C23C 16/4415 (2013.01); C23C 16/56 (2013.01); C23C 18/1666 (2013.01); C25D 11/26 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method, comprising:
anodizing a surface of an initial material to generate porous nanostructures extending into the surface, resulting in an anodized surface;
applying a surface mechanical attrition treatment (SMAT) to the anodized surface to generate an anodized material comprising the anodized surface and an enhanced charge trapping property as compared to the initial material, wherein the SMAT comprises:
arranging a ball between the anodized surface of the anodized material and an ultrasonic horn connected to an ultrasonic transducer configured to convert an electrical signal into an oscillating wave, wherein the ultrasonic horn is configured to emit a first wave at a specified frequency upon an oscillation of the ultrasonic horn;
emitting, by the ultrasonic horn, the first wave at the specified frequency;
inducing movement, by the first wave, of the ball, wherein the movement of the ball is induced to occur at a target ball speed selected to achieve a reorganization of atoms of the anodized material in a lattice structure, and wherein the target ball speed is selected to be a speed at which more than the reorganization of the atoms does not substantially occur; and
colliding the ball, at the target ball speed with the anodized surface of the anodized material to achieve the reorganization of the atoms of the anodized material to comprise a lattice strain, of the anodized surface resulting in the enhanced charge trapping property of the anodized material.