合金化和热处理对难熔金属硅化物基合金组织和性能影响的研究现状  

Effects of Alloying Elements and Heat Treatments on the Microstructure and Mechanical Properties of Refractory Metal Silicide-Based Alloys

作　　者：贾丽娜[1] 郭喜平[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2007年第7期1304-1308,共5页Rare Metal Materials and Engineering

基　　金：教育部新世纪优秀人才支持计划;国家自然科学基金(50271056)资助

摘　　要：综述了合金化和热处理对硅化物基合金组织和性能的影响。在铌硅化物基合金中添加Mo,W或Al后,电弧熔炼态组织中的硅化物相为βNb5Si3;添加Cr或者V后,硅化物相为αNb5Si3;加入Ti后,硅化物相是Nb3Si。添加Ti,Hf和B可提高铌硅化物基合金的室温断裂韧性,添加W或Mo后合金的高温强度显著提高,而添加Cr,Al和Ti明显改善其高温抗氧化性能。在MoSi2中加入W,Nb和Ge等合金化元素后分别形成(Mo,W)Si2,(Mo,Nb)Si2或Mo(Si,Ge)2等硅化物,但在钼硅化物基合金中添加B后生成α-Mo,Mo3Si和T2相(MoSiB2),并且T2相所占的体积百分比与B的含量成正比。α-Mo相的含量对合金的断裂韧性和抗氧化性有重要影响。Nb或Mo的硅化物基合金的热处理温度都比较高,经过再结晶退火后合金中的组成相及其所占的体积百分比均发生变化,并且组织粗化,但分布更加均匀,从而对力学性能有显著的影响。The effects of alloying elements and heat treatments on the microstructure and mechanical properties of refractory metal silicide-based alloys have been reviewed in this paper. The silicides in arc-melted Nb-Si based alloys are β NbsSi3 after adding W, Mo or Al elements, αNbsSi3 after adding Cr or V, and Nb3Si after adding Ti. The microstructure of the arc-melted Nb-Si-Ti alloys is composed of Nb3Si and Nbss. For the Nb-Si based alloys, adding Ti, Hf and B elements can improve the room temperature fracture toughness, the high temperature strength can be increased by the addition of Mo and W, and adding Cr, Al and Ti can enhance their high temperature oxidation resistance. In the MoSi2 based alloys, the silicides （Mo,W）Si2, （Mo,Nb）Si2 or Mo（Si,Ge） 2 are formed after the addition of W, Nb and Ge elements. For the Mo-Si-B alloys, the T2 phase is formed due to the addition of B, and its volume fraction increases with the increase of B content. The volume fraction of α-Mo phase plays an important role on the fracture toughness and oxidation resistance of Mo-Si-B alloys. The heat-treatment temperature is always rather higher for the refractory metal silicide based alloys. The microstructure is slightly coarser and the distribution is more uniform after heat treatments and annealing, obviously affecting the mechanical properties of alloys due to the changes of component phases and their volume fractions.

关 键 词：铌硅化物 组织 合金化元素 钼硅化物 热处理 

分 类 号：TG113[金属学及工艺—物理冶金]