Optimization of process parameters in rotary ultrasonic-assisted drilling of quartz

Abstract Processing hard and brittle quartz glass using traditional production methods is challenging. Thus, ultrasonic machining is the recommended method for working with these types of materials. This paper explores the machining of quartz material through rotary ultrasonic drilling (RUD) using a trepanning tool. The study investigates the effect of ultrasonic power, tool rotational speed, feed rate, and pecking drilling depth parameters on chipping area (CA), material removal rate (MRR), and surface roughness (SR). The design of the experiments utilized response surface methodology (RSM) with the Box-Behnken design. The optimal process parameters (26th) were determined by ranking the gray relational grade (GRG) in gray relational analysis (GRA) based on the results of all 27 experiments. The settings of the 26th experiment were as follows: ultrasonic power ( P ) was set to 90%, tool rotational speed ( n ) to 1300 rpm, feed rate ( V f ) to 30 mm/min, and pecking drilling depth (dp) to 0.75 mm, and the results were CA = 56.96 mm 2 , SR = 1.222 µm and MRR = 162.68 mm 3 /s. The optimum parameters ( P = 60%; n = 1600 rpm; V f = 30 mm/min; dp = 0.40 mm) were determined by calculating the average GRG for each parameter level using GRA. The desirability approach in multi-response optimization was used to determine the optimum values for the parameters ( P = 61.52%; n = 1478.79 rpm; V f = 28.18 mm/min; dp = 0.69 mm). The RSM analysis revealed that these settings resulted in a minimum CA of 55.93 mm 2 , a minimum SR of 0.938 µm, and a maximum MRR of 147.63 mm 3 /s. Additional experiments were conducted with the RUD and CD (conventional drilling) method with the ideal configuration. As per the GRA analysis, the parameter of rotating speed of the tool had the most influence on its results of CA, SR, and MRR. ANOVA analysis revealed that the factors with the most effect were P for SR, n for CA, and V f for MRR.