Improving Surface Roughness of 42CrMo4 Low Alloy Steel Shafts by Applying Varying Feed in the Multi-Pass Slide Burnishing Process

Burnishing is a critical surface finishing process that uses a hard tool to apply pressure on the surface, lasting one or multiple passes to plastically deform surface asperities on high-performance alloys like 42CrMo4 steel. But the conventional method fails to efficiently enhance surface properties by selecting specifically the values of feed in all passes that follow the same path, missing uneven asperities. In this study, surfaces are burnished with multiple passes by changing the feed in each pass, hypothesizing that the approach can optimize the plastic deformation mechanism. By applying this approach, the tool’s path is deviated from its previous path to enhance the surface integrity by targeting residual surface anomalies. Controlled four levels of forces (60, 90, 120, 150 N), four feed levels (0.02, 0.08, 0.14, and 0.2 mm/rev), and three levels of passes (2, 3, 4) were applied on the proposed method and the conventional method to evaluate and compare their effects. Experimental results confirmed better surface roughness by the varying feed approach, demonstrating its efficacy in enhancing finishing quality through controlled plastic deformation. The analyzed S_a, S_sk, S_ku, S_k, S_pk, and S_vk showed changed topography by both methods, specifically 0.02 mm/rev feed in the old and feed combination in the feed-varying method, which included 0.02 mm/rev, produced smoother surfaces, but the highest elapsed time. The findings generally highlight the potential of adaptive feed strategies to overcome limitations of conventional burnishing, offering a viable solution for precision finishing of high-performance alloys.