Cutting force modeling in high-speed machining of selective laser melted Ti6Al4V alloys based on a modified constitutive model considering thermally activated effect

The thermally activated effect can produce a vital influence on the mechanical property and cutting force of metal materials in the machining process. An insight can be gained into the action criteria of the thermally activated effect on the cutting force, which provides a solid basis of the research of material performance and machinability. In this study, a cutting force model of selective laser melted (SLMed) Ti6Al4V alloy is proposed by introducing the modified constitutive model with thermally activated effects and the analytical model of the deformation zone into the cutting force model. The anisotropic properties of SLMed Ti6Al4V alloy under different scanning strategies (0 degrees, 67.5 degrees, and 90 degrees) are explored by combining with the cutting force model, constitutive model and analytical model of deformation zone (primary deformation and tool-chip contact area). The action of thermally activated effects on the cutting force, primary deformation and tool-chip contact zone is also researched in detail. Milling experiments and predictions of SLMed Ti6Al4V alloy under different scanning strategies have been implemented to reveal the effectiveness of this new model. The comparison results indicate that the proposed milling force model can effectively predict milling force and reflect well on the anisotropy of SLMed Ti6Al4V alloy. In addition, this proposed force model can well analyze the action mechanism of the thermally activated effect on the milling force of SLMed Ti6Al4V alloy, which is significantly essential for the machining mechanism research in terms of a microscopic perspective.