Papers by Keyword: Ball-Burnishing

Abstract: In this paper, we have developed a physical model to predict the forces of the ball burnishing. The models have been constructed on the basis of the plasticity theory. During the model development we have Fig.d out the dimensionless number B that characterizes the problem of plastic deformation in the ball-burnishing. The experiments performed in steel and aluminum allows to validate the model and to emphasize the correct prediction of behavior patterns that the model describes.

Abstract: In this paper the ball burnishing as a finishing process for sculptured surfaces is studied. This technique is a quick, easy and economical process for a significant improvement of high-end parts. Aiming at the burnishing of complex parts, different strategies are possible. In this case two strategies are presented: continuous burnishing (CB) using 5-axis interpolation and patch burnishing (PB) using 3+2 axis interpolation. Two parts have been previously machined in five-axis and then finished using ball burnishing techniques. The first one is an AISI 1045 hemisphere and the second one is a DIN 1.2379 part (64 HRC). Surface quality has been evaluated for both strategies obtaining a significant improvement of surface roughness and hardness.

Abstract: 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.