热暴露对Nb/NbCr_2合金组织及性能的影响  

Effects of Thermal Exposure on Microstructure and Properties of Nb/NbCr_2 Alloy

作　　者：邓莉萍[1,2] 鲁世强[2] 虞文[2] 林彦[2] 

机构地区：[1]南京航空航天大学,江苏南京210016 [2]南昌航空大学,江西南昌330063

出　　处：《材料科学与工程学报》2013年第5期655-659,共5页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51074092);江西省自然科学基金资助项目(20122BAB206016)

摘　　要：采用机械合金化+热压工艺制备了成分为Cr-77.5at.%Nb的Nb/NbCr2合金。分别在800,1000,1200℃对其进行10,30,50,100h的真空热暴露实验,研究热暴露对合金组织及性能的影响。结果表明,随着热暴露温度升高和时间延长,Nb/NbCr2合金的相对密度略有增加,1200℃热暴露100h后,合金的相对密度由热暴露前的99.1%增大至99.6%。合金在整个热暴露过程中没有明显的物相变化。合金的维氏硬度随着热暴露时间的延长呈现先升后降的变化趋势;随着热暴露温度升高和时间延长,合金的断裂韧度逐渐下降;合金的室温抗压强度和塑性应变随热暴露时间的延长逐渐增大,屈服强度随热暴露时间延长先增后降。Nb/NbCr2 alloy with the composition of 77.5at. %Nb was prepared by mechanical alloying and hot pressing. To investigate the effects of thermal exposure on microstructure and properties of Nb/NbCr2 alloy,the samples were exposed to vacuum at 800℃, 1000℃ and 1200℃ for 10h, 30h, 50h and 100 h, respectively. The results show that the relative density of Nb/NbCr2 alloy increases with the thermal exposure temperature raise and time prolonging, varying from 99.1 % to 99.6% after 100 h thermal exposure at 1200℃. No obvious phase transformation can be observed during the whole thermal exposure process. Vickers hardness of Nb/NbCr2 alloy increases firstly and then decreases with the thermal exposure time. Meanwhile, fracture toughness of Nb/NbCr2 alloy decreases with the increase of thermal exposure temperature and thermal exposure time. Compressive strength and plastic strain of Nb/NbCr2 alloy increase gradually with the elapse of thermal exposure time, while the yield strength of Nb/NbCr2 alloy increases firstly and then decreases.

关 键 词：NB NbCr2合金 热暴露 组织 性能 

分 类 号：TG146.416[一般工业技术—材料科学与工程]