The Concepts and Properties of Nano-Skin Materials and Components Created by Ultrasonic Nanocrystal Surface Modification

Abstract

Material surface and immediate subsurface layers can be called "skin". A novel Ultrasonic Nanocrystal Surface Modification (UNSM) technology produces uniformed micro dimples on the top surface and nanometer grain in the subsurface; increases surface hardness and induces compressive residual stress, therefore mechanical characteristics related to fatigue, wear, friction, etc. can be improved. The concepts and properties of nanoskin materials and components are proposed with their potential application.

Effect of ultrasonic nanocrystal surface modification on residual stress and fatigue cracking in engineering alloys

“…The use of mechanical work to transfer energy into materials is used widely for improvement of the surface properties and fatigue life . Surface treatment processes such as laser shock peening, shot peening, ultrasonic shot peening, and ultrasonic nanocrystal surface modification (UNSM) are now used for improvement of the fatigue, wear, and surface properties of materials .…”

“…The UNSM is a novel surface treatment process for improvement of the fatigue characteristics and wear rate of engineering materials. In comparison to shot peening, laser shock peening, and other techniques, the lower cost, better control, and ease in application of UNSM make it an ideal choice for surface treatment of engineering alloys . It is a cold working process that decomposes the surface microstructure into a nanostructured layer and hardens the target material.…”

“…The UNSM has been applied for improvement in wear and fatigue properties. Pyoun et al applied UNSM on various engineering alloys and improved their surface roughness and fatigue properties. Cao et al, Suh et al, and Wu et al used UNSM on steel alloys for improvement of their fatigue strength.…”

Research of Aisi 321 Steel Microrelief After Ultrasonic Impact Treatment With Marker Applying

“…В настоящее время многие исследователи [1][2][3][4][5][6][7][8][9], как и наш исследовательский коллектив, имеют затрудне-ния с получением полностью регулярного микрорельефа методом УУО (рис. 1).…”

“…Большое число исследователей в своих работах [1][2][3][4][5][6][7]9, 10] показали, что УУО улучшает физико-механические и триботехнические характеристики, а также усталостную прочность различных деталей и узлов трения, в том числе и благодаря наличию регулярного микрорельефа, состоящего из выступов и впадин (мик-роямочек). Синонимы для словосочетания «регулярный микрорельеф», употребляемые в научной литературе -«поверхности, текстурированные микроямочками» или «наногофрированные поверхности».…”