热处理对Nb-10Si合金显微组织的影响  

Effect of heat-treatment on microstructures of the Nb-10Si alloy

作　　者：曲士昱[1] 王荣明[1] 韩雅芳[1] 

机构地区：[1]北京航空材料研究院,北京100095

出　　处：《航空材料学报》2001年第3期9-12,共4页Journal of Aeronautical Materials

基　　金：国防科技预研基金 ( 99J1 2 .1 .5 HK5 1 0 2 )

摘　　要：采用真空电弧熔炼法制备了 Nb-1 0 Si ( at% )合金 ,并在 1 85 0℃和 1 5 5 0℃温度氩气保护下进行了 2～ 1 0 0 h的热处理。综合通过 X射线衍射、透射电子显微术、扫描电子显微术及 X射线能谱对合金的显微组织进行了研究。结果表明 ,铸态 Nb-1 0 Si合金由连续的 Nb3 Si基体与均匀分布的 Nb相组成 ,1 85 0℃温度下热处理 2 h后 ,Nb晶粒明显长大 ;而在 1 5 5 0℃热处理后 ,Nb晶粒尺寸基本不变 ,Nb3 Si逐渐转变为 Nb和 Nb5Si3 相 ,且它们之间存在着一定的取向关系。1 5 5 0℃热处理 1 0 0 h后可以获得稳定的 Nb+ Nb5Si3 双相显微组织 。The Nb-10Si (at. %) alloy has been fabricated using the vacuum arc-melting method and heat-treated at 1850 C and 1550 C temperature for 2∼100 hours in Ar atmosphere. The effect of heat-treatment on microstructures of the alloy has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with X-ray energy dispersive spectrum (EDS) and transmission electron microscopy (TEM). The results show that 1550 C/100h is the optimum heat-treatment to acquire the equilibrium Nb+Nb5Si3 two-phase microstructure. The microstructure of Nb-10Si alloy in the as-cast condition consists of the continuous Nb3Si matrix and the dispersed Nb particles, which implies that the alloy is in the metastable equilibrium state. In the case of 1850 C/2h heat-treatment the Nb particles coarsen evidently, however, in the case of heat-treatment at 1550 C for 25 to 100 hours the growth of Nb particles is unconspicuous. After heat-treatment at 1550 C, Nb3 Si phase transforms the equilibrium Nb5Si3 and Nb phase with increase of heat-treatment time gradually. TEM observations reveal that there are certain orientation relationships between the niobium silicide and Nb phase.

关 键 词：Nb-10Si 显微组织 热处理 铌硅合金 X射线衍射 Nb3Si基体 铌相 

分 类 号：TG146.416[一般工业技术—材料科学与工程] TG15[金属学及工艺—金属材料]