Improving the polishing process for Rockwell hardness test block

Abstract

Inefficiencies in a Rockwell hardness test block manufacturing process were analyzed. The polishing stage was identified to be the bottleneck with a high reworking rate. An understanding based on the physics of polishing was the first step. Then a DOE analysis was implemented to find the optimum parameters of polishing process. A range of solutions were implemented and improvements were observed. Adding compliance, introducing two stages of polishing and using a different pad and slurry were key elements in improving the polishing process. Various quality control factors were assessed. Early analysis of those optimized parameters appeared promising; where the average polishing cycle times for brass and steel were reduced from 20 minutes to less than 2 minutes and 4 minutes, respectively. Meanwhile the quality of surface finish was improved significantly.