关键词: 超声铣削, 铝合金, 粗糙度, 疏水性

Abstract: To address the phenomenon that ultrasonic-assisted machining might improve the microstructural properties of high-strength aluminum alloy surfaces by forming micro-scoring surfaces on the workpiece surfaces, an experimental study on the microstructure of surfaces milled by single-excitation rotary ultrasonic longitudinal torsion composite milling was conducted: the effects of machining parameters on the water contact angle were analyzed based on the water contact angle theory and the kinematic theory of longitudinal torsion milling; secondly, a single-excitation ultrasonic longitudinal torsion milling test platform was built, and the orthogonal method was used to study the effects of different machining parameters on the surface roughness, milling forces and surface wetting performances. The results show that the surface quality is best when the ultrasonic amplitude is as 4 μm, and the cutting speed and feed are positively correlated with the surface roughness and water contact angle; the surface water contact angle under ultrasonic machining mode is larger than that of the normal mode, and the surface water contact angle machined by low amplitude is larger than that of high amplitude during ultrasonic machining. And the differences between the surface water contact angle machined by high amplitude and low amplitude are not significant when the speed reaches a certain amount. Suitable machining parameters under the ultrasonic longitudinal twist processing method may reduce the roughness of the machined surfaces and change the wettability of the surfaces.

Key words: ultrasonic milling, aluminum alloy, roughness, wettability