Study on the Machinability of Cryogenic Milling for Compacted Graphite Iron; CGI 주철 소재 극저온 밀링 공정 절삭성 분석 연구

초록

Compacted graphite iron (CGI) has been widely used in the automobile industry because of its good mechanical properties. CGI has better strength as compared to grey iron due to its internal structure. It includes graphite particles, which enhance the adhesion between graphite and iron. However, the material characteristics can negatively affect the machinability. In this study, cryogenic milling was performed for CGI450. It is well known that cryogenic machining is effective in improving the machinability. The process included spraying liquid nitrogen as a cryogenic coolant, and the influences on machinability were experimentally investigated with a focus on the cutting force and surface roughness. When liquid nitrogen was sprayed, the cutting force was slightly increased due to the cold-strengthening effect. On the other hand, surface roughness was dramatically decreased by 44.7% as compared to dry milling because brittleness of work material was increased by cryogenic coolant spraying. © © The Korean Society for Precision Engineering

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