In order to obtain better quality TA10 pipes, the Boring and Trepanning Association (BTA) deep-hole drilling process is used. However, this type of machining leads to difficult chip removal, tool wear, and poor hole-surface quality. In this study, a deep-hole drilling experiment was conducted on TA10 workpieces using the designed tool with different process parameters, and the process parameters were optimized by machining results with multiple objectives such as chip morphologies, tool wear, hole-axis deflection, and hole surface roughness. The results show that different process parameters have a great impact on the cutting process, with a higher feed resulting in smoother chip removal and a lower spindle speed resulting in lighter tool wear and less hole axis deflection. When the spindle speed is 145 r/min and the feed is 0.12 mm/r, the machined TA10 pipe meets both the accuracy requirement of roughness and the machining efficiency.

In this study, the cutting parameters for machining deep bottle holes (deep holes with complex profiles and length-to-diameter ratio greater than 10) were optimized based on cutting simulation, a regression analysis genetic algorithm, and experimental validation. The influence of cutting parameters on cutting force and cutting temperature was analyzed using the response surface method (RSM), and the regression prediction model of cutting parameters with cutting force and most cutting temperature was established. Based on this model, multi-objective optimization of cutting force F_x and material removal rate Q was carried out based on a genetic algorithm, and a set of optimal cutting parameters (v = 139.41 m/min, a_p = 1.12 mm, f = 0.27 mm/rev) with low cutting force and high material removal rate were obtained. Finally, based on the optimal cutting parameters, the machining of TC4 deep bottle holes with a length-to-diameter (L/D) ratio of 36.36 and a roughness of Ra 3.2 µm was accomplished through a deep hole boring experiment, which verified the feasibility of the selected cutting parameters and provided a certain reference for the machining of this type of parts.

There is a growing interest in developing an advanced technique to manufacture titanium alloy for larger holes in the aviation and marine industries. While the application of larger holes is limited due to the low machinability and high cost. The deep-hole trepanning is investigated to manufacture the titanium alloy in a high-efficient low-cost manner, and the technical challenges during the deep-hole trepanning process are studied in this article. Designs of the deep-hole trepanning tool and experiments under different cutting speeds and feed are carried out. Chip morphology, axial cutting force, and tool wear are analyzed. The optimal process parameters are achieved. This study provides a practical solution to process titanium alloy for potential industrial applications.