添加Nd元素对Ti-6Al-4V-2Cr合金组织细化的影响  

Effects of Nd element addition on microstructure refinement of Ti-6Al-4V-2Cr alloy

作　　者：王文焱[1,2] 黄文君[1] 邵昌 张豪胤 史士钦 谢敬佩[1,2] 黄亚波[1] 刘冀尧 

机构地区：[1]河南科技大学材料科学与工程学院,洛阳471003 [2]有色金属共性技术河南省协同创新中心,洛阳471003 [3]新疆闽龙耐磨材料有限公司,新疆833200 [4]厦门大学材料学院,厦门361005

出　　处：《粉末冶金材料科学与工程》2016年第5期760-766,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：河南省重大科技专项(102105000007)

摘　　要：采用冷等静压–真空烧结法制备Ti-6Al-4V-2Cr-1Nd合金,然后进行固溶及时效热处理,通过实验与最小错配度理论计算,研究Nd元素对该合金组织细化的影响,并分析细化机理。结果表明,添加1%(质量分数)的稀土元素Nd后,析出相Nd2O3能有效促进晶粒细化。二维错配度的计算结果证明析出相Nd2O3是有效的形核剂,可促进非均匀形核,增加形核率,从而使晶粒细化。通过对合金试样薄区进行高分辨率观察,发现另一种絮状的、非常细小的、弥散分布的Nd2Ti4O11相,由于其界面错配度较低,也可作为非均匀形核的核心,促进形核,起到细化晶粒的作用。Titanium alloy Ti-6Al-4V-2Cr-1Nd is made by the cold isostatic pressing and vacuum sintering, then the solution and aging heat treatment was carried on the prepared of titanium alloy, the effect of Nd elements on the microstructure refinement and the refinement mechanism were researched and analyzed through the experiment and theory calculation of minimum mismatch degree. The results show that the main precipitation phase Nd2O3 can effectively promote the grain refinement after adding rare earth element 1% Nd（mass fraction）. The two-dimensional mismatch degree calculation results proved that the precipitated phase Nd2O3 is the effective nucleating agents that can promote the heterogeneous nucleation and increase the nucleation rate, thus promote the grain refinement. Through the high resolution observation of thin area in the sample, another precipitated phase Nd2Ti4O11 is found, which is flocculent, dispersed and very small. Because of the low degree of interface mismatch, Nd2Ti4O11 can also be used as the core of heterogeneous nucleation and promote nucleation, which means it can also play a role in grain refinement.

关 键 词：Nd元素 Ti-6Al-4V-2Cr-1Nd合金 错配度 析出相 形核剂 细化晶粒 

分 类 号：TG166.5[金属学及工艺—热处理]