Optimizing Processing Parameters and Surface Quality of TC18 via Ultrasonic-Assisted Milling (UAM): An Experimental Study

Abstract

This study conducted longitudinal ultrasonic-assisted milling (UAM) tests and optimized a combination of milling technological parameters to achieve high-quality machining of TC18 titanium alloy. The motion paths of the cutter under the coupled superposition states of longitudinal ultrasonic vibration and end milling were analyzed. Based on the orthogonal test, the cutting forces, cutting temperatures, residual stresses, and surface topographical patterns of TC18 specimens under different UAM conditions (cutting speeds, feeds per tooth, cutting depths, and ultrasonic vibration amplitudes) were examined. The differences between ordinary milling and UAM in terms of machining performance were compared. Using UAM, numerous characteristics (including variable cutting thickness in the cutting area, variable cutting front angles of the tool, and the lifting of the cuttings by the tool) were optimized, reducing the average cutting force in all directions, lowering the cutting temperature, increasing the surface residual compressive stress, and significantly improving the surface morphology. Finally, fish scale bionic microtextures with clear, uniform, and regular patterns were formed on the machined surface. High-frequency vibration can improve material removal convenience, thus reducing surface roughness. The introduction of longitudinal ultrasonic vibration to the end milling process can overcome the limitations of traditional processing. The optimal combination of UAM parameters for titanium alloy machining was determined through the end milling orthogonal test with compound ultrasonic vibration, which significantly improved the surface quality of TC18 workpieces. This study provides insightful reference data for subsequent machining process optimization.

Cutting-Force Modeling Study on Vibration-Assisted Micro-Milling of Bone Materials

“…where F i p is the ploughing force of the bone material in the corresponding cutting direction; b i is the cutting width in the corresponding cutting mode; τ i MN is the frictional shear stress of the bone material along the cutting edge in the corresponding cutting mode; l i MN is the length of the ploughing area in the corresponding cutting mode; η i is the angle between the cutting slip line and the bottom cutting surface in the corresponding cutting mode; and l i MN and η i can be obtained from Equations ( 9) and (10), respectively, according to the slip theory proposed by Waldorf.…”

“…Vibration-assisted machining technology is commonly employed for precision materials that are challenging to machine, such as titanium alloys [ 10 ] and high-temperature alloys, owing to its unique material-removal mechanism. Currently, the investigation of cutting forces in vibration-assisted machining of bone materials primarily revolves around vibration-assisted turning and vibration-assisted drilling.…”

Optimization Milling Force and Surface Roughness of Ti-6Al-4V Based on Ultrasonic-Assisted Milling (UAM): An Experimental Study

“…They also have high hardness, strength, and corrosion resistance, which makes them very likely to result in cutting chip fracture and blade cracking during machining, thus significantly affecting the efficient and precise machining of Ti alloys [ 8 , 9 ]. Ultrasonic-assisted milling (UAM) is based on the conventional milling (CM) method with the integration of ultrasonic vibration, which can convert high-frequency oscillation electrical signals into mechanical vibration using an energy transducer, thereby achieving intermittent cutting effect [ 10 , 11 ]. This technique can reduce the cutting force and improve the machining quality [ 12 , 13 , 14 , 15 ].…”