热处理对高铌TiAl基合金组织与性能的影响  

Influences of Heat Treatment on Microstructure and Performance of Ti-45Al-8Nb-0.5W-0.8B-0.2Si Alloy

作　　者：赵成志[1] 张贺新[1] 金天文 余娇娇[1] 姜铸航 

机构地区：[1]哈尔滨工程大学材料科学与化学工程学院,超轻材料与表面技术教育部重点实验室

出　　处：《特种铸造及有色合金》2016年第5期452-455,共4页Special Casting & Nonferrous Alloys

基　　金：哈尔滨市科技成果转化项目(2013DB4AG009)

摘　　要：高铌TiAl合金的铸态组织,粗大不均匀,有少量B_2相,长条状硅化物和硼化物沿晶界析出,使合金的室温塑性强度和断裂韧度降低。研究了均匀化处理和循环热处理等热处理方式对Ti-45Al-8Nb-0.5W-0.8B-0.2Si组织的影响。结果表明,采取均匀化处理,随炉加热到1 200℃,保温24h,空冷,再循环热处理,快速加热到1 150℃,保温4h,空冷,循环3次可获得理想的显微组织。The as cast microstructure of high-Nb contained TiAl-based alloys exhibits coarse and inhomogeneous,and there exists a little of B2 phase and long strip silicide and boride precipitated along the grain boundaries,resulting in the degradation of alloy plasticity,strength and fracture toughness at room temperature.The influences of different heat treatments on the structure of Ti-45Al-8Nb-0.5W-0.8B-0.2Si alloy were investigated,and homogenization heat treatment and cycle heat treatment were adopted to eliminate segregation,improve phase composition and refine layer microstructure.The results show that desirable microstructure can be observed in the alloy by the homogenization process along with the furnace heated to 1 200℃for 24 h,and then air cooling and then recycle heat treatment with rapidly heated to 1 150 ℃for 4h,air cooling,repeating the process three times.

关 键 词：Ti-45Al-8Nb-0.5W-0.8B-0.2Si 热处理 显微组织 

分 类 号：TG166[金属学及工艺—热处理] TG146.23[金属学及工艺—金属学]