Surface integrity of hard turned parts modified by ball burnishing

The purpose of this research is to test the applicability of ball burnishing for improving surface integrity produced in hard machining on parts made of high-strength, low alloy 41Cr4 steel with hardness of about 57 HRC. Machined surfaces were characterized using 2D and 3D scanning techniques. Moreover, the distribution of microhardness beneath the surface was determined and the microstucture of the sublayer was examined using SEM/EDS technique. This investigation confirms that ball burnishing allows producing surfaces with acceptable surface roughness and better service properties. The main conclusion is that this sequential technology can partly eliminate grinding operations when hard machining is not enough to produce the desired surface integrity.