Effects of fluid condition and material on surface damage in ultrasonic wet peening

Author:  Weingaertner, Kienzler, Hoffmeister, Schulze
Source:  Conf Proc 2011: ICSP-11 South Bend, IN USA (pgs. 399-404)
Doc ID:  2011067
Year of Publication:  2011
Abstract:  
Abstract Cavitation in solid-water mixtures generated by ultrasonic waves can be used to modify the topography of metallic surfaces. During ultrasonic irradiation two kinds of processes occur in the liquid: (a) material removal by bubble formation plus collapse and the resulting micro jets; (b) material removal by colliding or sliding of accelerated particles due to bubble formation plus collapse. Both processes allow the removal of burrs after micro milling. However high impact forces by bubble collapse often cause erosion pits on the surface which are detrimental to further processing. The aim of this research was to avoid the creation of erosion pits on metal surfaces which often lead to increased surface roughness. Therefore these investigations focus on reducing this effect by the variation of material properties of the workpiece and fluid conditions. Distilled water or a solution of sodium chloride both mixed with alumina grains of a mean diameter of 25