Machined Surface Quality For High-Speed Milling

High-speed machining (HSM) is one of the advanced manufacturing technologies in the last two decades, which is characterized by high speed, high feed rate and high precision. It is a cost-effective manufacturing process to produce parts with higher surface quality and can adapt to the keen competition and rapid change of the market. HSM technology has already been applied in many manufacturing industries. In practical operations, there are numerous new problems arising for both technical and theoretical aspects which need to be urgently solved. Surface quality is one of the most important factors in evaluating machining productivity and cutting performance, which is a significant design specification known to have considerable influence on parts properties such as wear resistance, ductility, tensile, and fatigue strength. However, the shortages of researches on surface quality predication and controlling techniques limit the development and reasonable application of the HSM technology, especially in studying the formation mechanisms of the machined layer affected by the non-uniform thermo-mechanical coupling intense stress fields in high speed cutting zones. Consequently, the surface integrity of the machined layer for high-speed milling is investigated based on the high-speed machining theory, thermo-elastic-plastic deformation theory and Finite Element Method (FEM) in the paper. The theory for the non-uniform thermo-mechanical coupling intense stress fields in high speed cutting zones is presented and applied to the analysis of the formation mechanisms of surface roughness, residual stresses and surface hardening. It is an important fundamental subject to promoting HSM technology development and application, which has a very important theoretical and practical significance to exploit HSM potential energy further. The modeling and analysis for the non-uniform thermo-mechanical coupling intense stress fields in high speed cutting zones are conducted on the basis of the thermo-elastic-plastic deformation theory and FEM techniques. The stress-strain constitutive equation of plastic materials in large plastic deformations is presented to follow the Prandtl-Reuss flow rule and the Von Mises yield criterion, possessing isotropically strain hardening characteristics. Meanwhile the flow stress is taken as a function of strain, strain rate and temperature. A new orthogonal cutting model for HSM is constructed according to Oxley's machining theory. The applicability of Oxley's machining theory is extended to the HSM. FE simulations are performed by using...