Sliding performance of machined grey cast iron surfaces after compliant abrasive surface polishing

Abstract

Currently, linear sliding guideways are fabricated using machining centers for roughing and drilling while grinding machines are used for finishing operations. As a consequence, large and heavy machine tool castings must be transferred back and forth multiple times between the different equipment. In an effort to eliminate workpiece transfers and reduce production costs, an alternative manufacturing process that utilizes hard milling followed by fine-finishing with a spindle mounted abrasive filament tool is proposed. The goal of the current paper is to determine process settings for the filament tool optimized for sliding friction coefficients between PTFE slider and cast iron slideway. Areal function parameters Sk, Spk, Svk and load bearing ratio were used to evaluate the surface texture after polishing with various filament tools. A two-level partial factorial experiment with five factors was conducted friction coefficients were measured to calculate the significant main effects and second-order interactions. The dynamic sliding performances of five types of surfaces (ground, milled, milled + polished) were tested at sliding speeds from 80 to 2000 mm/s. It was found that the filament tools with the largest grit and thickest bristles have the greatest impact on surface quality, the alternative polishing method results in lower static and dynamic friction coefficients and the new process is not expected to increase machining time based on theoretical cycle time analysis.