EMG activity analysis of expert skills on handheld grinding work for metallographic sample

Abstract

Carburizing is the most common heat treatment process for hardening ferrous alloy. The quality assurance of carburizing process requires metallographic analysis of case depth, retained austenite, intergranular oxidation, and carbide network by means of metallographic sample. Metallographic preparation consists of sectioning, mounting, plane grinding, polishing to mirror surface. It is difficult for non-expert to prepare metallographic sample with global mirror surface because preparation skill needs long time experience in this field. In this study, the difference of EMG activity during handheld grinding motion for metallographic specimen between expert and nonexpert execution was analyzed. The expert’s abductor pollicis brevis, extensor carpi radialis brevis, and triceps brachii were working activity than the other muscles. We considered that these muscle activity balance by the expert contribute to the stable grinding conditions and good surface finish.