Enhanced Mechanical Characteristics of Metal Alloys by the Ultrasonic Nanocrystal Surface Modification

Author:  Pyoun, Suh, Cho, Kim, Amanov
Source:  Conf Proc 2011: ICSP-11 South Bend, IN USA (pgs. 207-212)
Doc ID:  2011034
Year of Publication:  2011
Abstract:  
Abstract Ultrasonic nanocrystal surface modification (UNSM) technology is a surface enhancement technology analogous to shot peening, laser shot peening (LSP), ultrasonic peening (UP), deep rolling (DR) and low plasticity burnishing (LPB). The UNSM utilizes ultrasonic vibration energy to maximize coverage and stress-field density. In this process, a tool-steel, tungsten carbide or ceramic ball is attached to an ultrasonic device and strikes the surface of a workpiece 20,000 to 40,000 times per second and 1,000 to 100,000 shots per square millimeter. The UNSM treatment induces deep compressive residual stress comparable to LSP and DR, but improves surface roughness not like other technologies and also produces a uniformly distributed micro dimples on the surface. Steel alloys, Cu alloys, Ti alloys and Al alloys are treated by UNSM and their mechanical properties are analyzed and compared before and after UNSM treatment. Keywords: UNSM (Ultrasonic Nanocrystal Surface Modification) technology, Surface technology, Fatigue, Wear, Friction