Optimization of Machining Parameters for Stress Concentration in Microdrilling of Titanium Alloy

This study employed a Taguchi-based experimental design to determine the experimental layout and optimal machining parameters for stress concentration in the microdrilling of titanium alloy. The finite element method (FEM) was used to analyze the characteristics of stress concentration in microdrilled holes. The signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to determine the optimal levels and the order of significance of the identified critical parameters affecting stress concentration. The critical control parameters in this study included rotational speed (rpm), feed rate (mm/min), cutting fluid, and holding length (mm). Results show that finite element simulation can effectively analyze the stress concentration of microholes. The stress concentration factor in a specimen is related to its microhole quality. The maximum stress concentration factor of the drilled hole was 4.46 times that of an ideal hole.