Ultrasound treatment of centrifugally atomized 316 stainless steel powders.
Rawers-JC; McCune-RA; Dunning-JS
Metall Trans, A, Phys Metall Mater Sci 1991 Dec; 22A:3025-3033
The U.S. Bureau of Mines is studying the surface characteristics of rapidly solidified powders and the potential for surface modification of fine powders prior to consolidation. The surface modification and work hardening of fine powders were accomplished by applying high-energy ultrasound to centrifugally atomized austenitic 316 stainless steel powders suspended in liquid media. Cavitation implosion changed the surface morphology, hammering the surface and occasionally fretting off microchips of work-hardened metal. Ultrasound cavitation work-hardened metal powder surfaces, producing a strained, duplex austenite face-centered cubic (fcc)-martensite body-centered tetragonal (bct) phase structure. The amount of work hardening depended upon the quantity of ultrasound energy used, considering both power level and experimental time. Work hardening was relatively independent of the liquid media used.
OP; Journal Article
Metallurgical Transactions. A. Physical Metallurgy and Materials Science