Micro-turning of hard steel by single-grain ceramic cutter based on numerical simulations

To predict the evolutions of turning forces, temperatures and tool wears, finite element method (FEM) models for micro-turning by using cubic and spherical single-grain ceramic tools have been established. Single-grain ceramic tools with different grain sizes and shapes have been investigated. Initial and boundary conditions of numerical simulations have been adopted and the coefficients of archard models for different grain sizes have been obtained by reciprocating friction tests. The results are summarized as follows. Wear depths of spherical ceramic tools with size 1 μm are bigger than those caused by cube ceramic tools with the same conditions. The predicted maximum turning forces for globular single-grain tools are bigger than those of cube single-grain tool. Also, turning forces of three directions for cube single-grain ceramic tools with size 10 μm are significantly higher than those of single-grain ceramic tools with 1 μm. Wear depths increase sharply with the increase of single-grain ceramic tool sizes, and wear depths of cube single-grain ceramic tools with size 10 μm are bigger than those of 1 μm cube single-grain tool with the same turning condition. The obtained results would provide the fundamental and practical guidelines of single-grain ceramic tools choice for the hard micro-turning.