Cryogenic Machining With Brittle Tools and Effects on Tool Life

Abstract

With the current popularity of finish hard turning, the need for improved productivity and tool life is of significant importance to manufacturers. The present work explores the effects of cryogenic coolants in machining hardened materials, from an industrial perspective, with emphasis on productivity and tool life improvement, environmental effects, as well as reliable performance characteristics for brittle tools. Both alumina ceramic (Al2O3) and polycrystalline cubic boron nitride (PCBN) tools show significant tool life improvement in cryomachining of hard ferrous materials, such as 52100 bearing steel and A2 tool steel. Significant productivity gains have also been observed in cryogenic machining of WC-Co rolls with polycrystalline diamond (PCD) tools. The enhanced performance of cryomachining is attributed to more efficient heat removal from the cutting insert, as well as reduction in thermal softening of the cutting tools at higher temperatures.