Mechanisms of material-oriented ultraprecision diamond cutting

Abstract

<p indent="0mm">The fabrication of ultrasmooth surfaces by ultraprecision single-point diamond cutting has important applications in the cutting-edge fields of defense and aerospace. The promotion of the machining capability of diamond cutting has been severely impeded by the lack of a fundamental understanding of the underlying machining mechanisms. While diamond cutting is a highly coupled process between the cutting tool and the workpiece material, the workpiece material properties have a substantial impact on the machining process. This paper presents the mechanisms of diamond cutting of typical materials with different properties and microstructures. First, the heterogeneous machining mechanisms in the diamond cutting of polycrystalline copper are studied, with an emphasis on the effect of grain boundaries on the surface formation and the suppression strategy of the grain boundary surface step. Second, the brittle-to-ductile transition mechanisms in the diamond cutting of single-crystal silicon and single-crystal silicon carbide are investigated, with an emphasis on the improvement of the machinability of hard, brittle materials by employing the ultrasonic elliptical vibration-assisted cutting technology. Third, the cooperative deformation mechanisms of individual phases in the diamond cutting of reaction-bonded silicon carbide and silicon carbide reinforced-aluminum metal matrix composite are studied, with an emphasis on the influence of vibration assistance and cutting path on the surface formation. The findings reported herein provide a theoretical basis for the fabrication of the ultrasmooth surfaces of different materials using the ultraprecision diamond cutting technique.