Investigation of Deformation Gradients in Surface Zone of Mechanically Surface Treated CuZn30
The deformation degrees in near-surface zones and related microstructural changes in CuZn30 were determined after shot peening and ball-burnishing. The induced depths of plastic deformation increase with Almen intensity and rolling pressure in shot peening and ball-burnishing, respectively. As the ball size in burnishing increases, the depth of plastic deformation also increases. The local degrees of cold work within the affected depths were estimated by comparing micro-hardness values, penetration depths of induced slip bands as well as X-ray diffraction peak widths with those measured in blanks cold rolled to fixed degrees of plastic strain. The results clearly indicate that very high local deformation degrees above 80% are typically induced by mechanical surface treatments in areas very close to the surface with this deformation degree gradually decreasing with increasing distance to the surface. Depending on the intensity of ball-burnishing, deformation degrees still of the order of 10% were observed in regions having distances to the surface of as large as 1000 (m.
Young Won Chang, Nack J. Kim and Chong Soo Lee
S. B. Yi et al., "Investigation of Deformation Gradients in Surface Zone of Mechanically Surface Treated CuZn30", Materials Science Forum, Vols. 561-565, pp. 2229-2232, 2007