混粉超声振动对电火花加工Ti-6Al-4V表面结构及力学特性的影响  

Effect of Mixed Powder Ultrasonic Vibration on Surface Structure and Mechanical Properties of Ti-6Al-4V in Electro-Discharge Machining

作　　者：张云鹏[1] 孙广标[1] 张安洲[1] 

机构地区：[1]西北工业大学,陕西西安710072

出　　处：《稀有金属材料与工程》2014年第1期189-193,共5页Rare Metal Materials and Engineering

基　　金：大连理工大学精密与特种加工教育部重点实验室研究基金(JMTZ201103)

摘　　要：研究混粉超声振动对电火花加工Ti-6Al-4V表面结构及力学特性的影响,对传统电火花加工、混粉电火花加工及混粉超声振动电火花加工后Ti-6Al-4V试件的表面粗糙度、表面残余应力和显微硬度进行了测量,采用SEM对3种加工方法的加工试件表面重熔层及微裂纹进行了观察,采用能谱分析仪对加工表面进行了能谱分析,探讨了Al粉、SiC磨料超声振动对电火花加工表面结构和力学性能的影响机理。结果表明:在混粉电火花加工基础上,工作液中加入20 g/L的SiC颗粒,电极施加轴向超声振动,可使电火花加工表面粗糙度值Ra降低0.5μm、重熔层厚度减薄40μm、表面残余应力降低50 MPa、表面显微硬度由7650 MPa提高到9870 MPa。The effect of mixed powder ultrasonic vibration on the surface structure and the mechanical properties of Ti-6A1-4V in Electro-Discharge Machining （EDM） were studied. The surface roughness, the residual stress and the micro hardness of Ti-6A1-4V simples machined by conventional EDM, powder mixed EDM （PMEDM） and combination process of powder mixed EDM with ultrasonic machining （PMEDM＋USM） were measured, respectively. The recast layers and the surface cracks of samples machined by EDM, PMEDM and PMEDM＋USM were observed by SEM, the quantitative analysis of each element of samples machined by PMEDM and PMEDM＋USM was performed by energy spectrum analyzer. The effect mechanism of added A1 and SiC powder in kerosene and ultrasonic vibration of electrode on the surface structure and the mechanical properties of Ti-6AI-4V machined by PMEDM＋USM were also discussed. The results show that the surface structure and the mechanical properties of Ti-6A1-4V are improved by PMEDM＋USM. With under the effects of the electrode ultrasonic vibration and SiC added in kerosene, the surface roughness decreases by Ra 0.5 btm, the recast layer reduces by 40 p.m, the surface residual stress decreases bv 50 MPa. and the surface hardness increases from 7650 to 9870 MPa than PMEDM.

关 键 词：钛合金 超声振动 表面结构 残余应力 显微硬度 

分 类 号：TG661[金属学及工艺—金属切削加工及机床]