粉末冶金工艺参数对新型医用TiMoTaNbZr合金热变形行为的影响  

Effect of Powder Metallurgy Process Parameters on Thermal Deformation Behavior of New Medical TiMoTaNbZr Alloy

作　　者：胡威威 李伟[1] 马琳[1] 赵丰停 刘琪 HU Weiwei;LI Wei;MA Lin;ZHAO Fengting;LIU Qi(College of Material and Metallurgy,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学材料与冶金学院,贵阳550025

出　　处：《有色金属工程》2019年第1期5-12,共8页Nonferrous Metals Engineering

基　　金：贵州省科学技术基金项目(黔科合J字[2013]2102号)~~

摘　　要：以各合金元素粉末为原料,通过混料、冷等静压及真空烧结制备了新型医用Ti-14Mo-2. 1Ta-0. 9Nb-7Zr合金。通过改变压制压力、烧结保温时间等工艺参数制备合金,然后在变形量为60%、变形温度为900℃、变形速率为0. 01 s-1的条件下对合金进行高温热变形处理。利用X射线衍射(XRD)、光学显微镜(OM)及真应力-真应变曲线,表征分析了粉末冶金制备工艺参数对合金热变形行为的影响。结果表明,合金热变形后组织沿变形方向成纤维状,形成流线;粉末冶金法制备的合金强塑性好,且保温时间越长、制备压力越大,合金强塑性越好;合金在高温变形的条件下,发生动态回复和动态再结晶。动态回复阶段流变应力随着应变量的增加而增加,动态再结晶阶段则相反,再结晶完成后,合金进入稳态流变阶段。A new medical Ti-14Mo-2.1Ta-0.9Nb-7Zr alloy is prepared from alloy elements powder by mixing, cold isostatic pressing and vacuum sintering.The alloy was prepared by changing the pressing pressure and sintering holding time, and then the alloy was subjected to high temperature thermal deformation at the deformation amount of 60%, the deformation temperature of 900 ℃, and the deformation rate of 0.01 s -1 . The effects of powder metallurgy preparation parameters on thermal deformation behavior of the alloy were characterized by X-ray diffraction (XRD), optical microscopy (OM) and true stress-true strain curves. The results show that microstructure of the alloy is fibrillated along the deformation direction after the thermal deformation of the alloy, and the flow line is formed.The alloy prepared by powder metallurgy process has good strength and plasticity, and the longer the holding time,the higher the preparation pressure, the better the alloy's strong plasticity. Under the condition of high temperature deformation, the alloy can be dynamically recovered and recrystallized. In the dynamic recovery stage, the flow stress increases with the increase of strain, while the dynamic recrystallization stage is reversed. After the recrystallization is completed, the alloy enters the steady rheological stage.

关 键 词：粉末冶金 钛合金 工艺参数 热变形 真应力-真应变曲线 

分 类 号：TG146.2[一般工业技术—材料科学与工程]