Research on the influence of materials on surface quality in oscillating smoothing process

Abstract

This article studies the influence of materials on the surface quality of machine parts after vibratory burnishing. The surface quality of the parts after burnishing is evaluated by measuring roughness, hardness, residual stress, microhardness, and grain structure. The research results show that the surface of the parts after vibratory burnishing with different materials reduces roughness (Ra) by 4 to 7 times; the softer the material, the greater the reduction in roughness after burnishing. Compressive residual stress is formed at the surface layer, while tensile residual stress occurs near the center region, with the maximum compressive residual stress located 1 to 1.5 mm from the surface of the part. Grain size changes only occur in the surface layers, with an average reduction of 33 to 40% along the axial direction of the sample and 35 to 41% towards the center. The microhardness of the surface layer after vibratory burnishing increases by 14 to 23%, and the depth of the surface hardening process of the part is 0.35 to 0.60 mm, with greater hardening depth for softer materials.