增材制造钛合金超声振动辅助车削性能研究OA

Additive manufacturing of titanium alloys is widely used in aerospace,medical,and high-end equipment due to its high design freedom,high material utilization,and excellent mechanical properties.However,due to issues such as insufficient surface quality and accuracy,further machining is required.Studies have shown that two-dimensional ultrasonic vibration turning can effectively improve the surface roughness,surface hardness,and tool life of machined materials.The work aims to conduct turning experiments on titanium alloys additively manufactured with two-dimensional ultrasonic vibration-assisted turning technology under different feed rates and machining environments,followed by a comprehensive analysis of cutting force,surface roughness,surface hardness,and tool adhesion.The cutting forces under different machining conditions were measured by a Kistler 9257B dynamometer.Surface morphology under different feed rates was observed with a Super Viewer surface profiler to compare conventional turning and two-dimensional ultrasonic vibration turning(Fig.4),and then surface roughness was measured(Fig.5 and Fig.6).In addition,based on different dry and wet environments,surface hardness under different feed rates in conventional and two-dimensional ultrasonic vibration-assisted machining was measured with a digital micro-Vickers hardness tester TMVS-1(Fig.7),and the reasons for higher surface hardness under ultrasonic vibration in different environments were analyzed.Tool surface adhesion and EDX composition of adhered materials under different machining methods were analyzed(Fig.8),and the effects of two-dimensional ultrasonic vibration turning on tool adhesion were discussed.Under dry cutting conditions,compared to conventional turning,two-dimensional ultrasonic vibration turning could reduce the main cutting force by up to 25.50%at a feed rate of 0.05 mm/r.Under wet cutting conditions,the main cutting force in two-dimensional ultrasonic vibration turning could decrease by as much as 22.73%compared to conventional turning.However,when the feed rate increased to 0.15 mm/r,the difference in main cutting force between two-dimensional ultrasonic vibration turning and conventional turning was minimal for both dry and wet cutting,and this gap further narrowed with the increasing feed rate.The surface textures of workpieces processed by conventional turning and two-dimensional ultrasonic vibration turning showed clear differences.The surface after conventional turning exhibited a"ploughing"texture,while the surface after two-dimensional ultrasonic vibration turning showed a"fish scale"pattern.Two-dimensional ultrasonic vibration turning reduced surface roughness by 21.28%to 37.11%under dry cutting,and by 14.68%to 38.63%under wet cutting,compared with conventional turning.The average hardness of additively manufactured titanium alloys was higher in two-dimensional ultrasonic vibration turning than in conventional turning,because two-dimensional ultrasonic vibration effectively reduced cutting temperature,mitigating high-temperature softening.Due to ultrasonic vibration,adhesion on the tool's rake face was less during two-dimensional ultrasonic vibration turning than during conventional turning.Under wet cutting conditions,tool surface adhesion was lower than under dry cutting for both methods.Under the same turning parameters,compared with conventional turning,two-dimensional ultrasonic vibration turning better reduces the main cutting force and surface roughness,while providing higher workpiece surface hardness and improved anti-adhesion performance on the tool surface.