Effects of Ultrasonic Nanocrystal Surface Modification (UNSM) on Residual Stress State and Fatigue Strength of AISI 304

Abstract

The effects of a new mechanical surface treatment method, called ultrasonic nanocrystal surface modification (UNSM), on near-surface microstructures and residual stress states as well as on the fatigue behavior of an austenitic steel AISI 304 are investigated and discussed. The results are compared with consequences of other mechanical surface treatment methods such as deep rolling or shot peening.

A systematic study of mechanical properties, corrosion behavior and biocompatibility of AZ31B Mg alloy after ultrasonic nanocrystal surface modification

“…UNSM treatment leads to the decomposition of large crystalline structures into micro-level grains. Mg alloys with refined grains have been reported to exhibit high wear resistance [39,40], which can be further improved by ECAP extrusion due to surface hardening [62]. A similar situation occurs for extruded Mg-Dy-Zn alloys [63], where the improved wear behavior results…”

“…Additionally, UNSM improves material mechanical properties significantly and adjusts the surface topography by producing homogeneous grooves with relatively uniform roughness and topography [37][38][39][40][41][42] on many metalic alloys. These patterns are beneficial to the adhesion, migration and even differentiation of cells, e.g.…”

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».…”

Effect of ultrasonic nanocrystal surface modification on the characteristics of AISI 310 stainless steel up to very high cycle fatigue

“…This produces a compressive residual stress field in the material, which can go as deep as 500 µm into the surface. The plastic deformation and compressive residual stresses help in delaying the fatigue crack initiation and improving the fatigue life of the material …”