Cutting Simulation of Titanium Alloy Drilling with Energy Analysis and FEM

Abstract

The drilling of titanium alloy has been increasing in airplane and implant industries. The surface quality is a critical issue in terms of reliability for the parts. Therefore, the surface finishes should be evaluated for the cutting parameters in the manufacturing processes. FE analysis is effective in evaluation of not only the cutting process but also the affected layer in subsurface. However, the time for analysis depends on the computer hardware. Because the drilling analysis takes a long time on the normal performance of the computer hardware, it is actually difficult to optimize the cutting parameters and the tool geometries. The paper presents a hybrid simulation of drilling to save the time for analysis. In the hybrid simulation, the FE analysis is conducted in a 2D model determined by the energy analysis for the cutting force prediction. In the energy analysis, the 3 dimensional chip flow in drilling is modeled with piling up the orthogonal cuttings in the plane containing the cutting and the chip flow directions. Then, the FE analysis is applied to the orthogonal cutting model at the end of the lips, which control the surface quality of the drill hole. The cutting forces and the plastic strains in subsurface are shown in the hybrid analysis. The hybrid analysis is applied to drilling of titanium alloy. The hardness tests were conducted to verify the damage area simulated on a nano-indentation machine. Although the presented analysis is an approximation approach, the cutting process is evaluated in a short time in terms of the surface quality.