Study on the effect of frequency tracing in ultrasonic-assisted drilling of titanium alloy

Drilling titanium alloys are difficult because of the inherent material properties, particularly the low thermal conductivity and high chemical reactivity. This paper presents the design of a frequency tracing system and the experimental investigation in ultrasonic-assisted drilling (UAD) of titanium alloy. In order to realize the degree of influence between developed frequency tracing system and cutting parameters (frequency tracing, operating voltage, drill diameter, feed rate, and spindle speed) in UAD of titanium alloy, a L-18 (2 x 3(7)) orthogonal array was employed. Based on the experimental results, the importance of drill diameter, feed rate, and spindle speed in assessing thrust force is highlighted. On the other hand, average thrust force reduction of 3.2% was realized with frequency tracing compared to without the frequency tracing counterpart in UAD of titanium alloy. Moreover, the best combination to get lower thrust force in UAD of titanium alloy is A(2)B(2)C(3)D(1)E(3) (i.e., frequency tracing = YES, operating voltage = 500 V, drill diameter = 3 mm, feed rate = 10 mm/min, and spindle speed = 1,000 rpm) within the selected test range.