摘要
研究了B、Hf、Y微合金化高铌TiAl基合金的铸态及热处理后的微观组织。光学显微组织观察表明,B、Hf、Y微合金化高铌TiAl合金铸态组织为近层片组织,其α2/γ层片团得到细化;XRD分析表明,除了α2和γ相,在铸态组织中还含有β(B2)、Y2O3、YAl2。扫描电镜结合能谱分析表明,β(B2)相分布在层片团的边界附近,粒状Y2O3和YAl2分布在晶内和晶界,硼化物以条状或粒状分布在晶内和晶界。经过1260℃/20h+900℃/30min/AC热处理后,得到由α2/γ细小层片团与等轴γ晶粒组成的双态组织,β(B2)相基本消除,同时YAl2相消失,形成了富Hf的Y2O3和富Nb的钛硼化物。
The as-cast and heat-treated microstructure of B, Hf, Y micro-alloyed TiAl-based alloy with high Nb content were investigated. The OM observation shows that, the as-cast microstructure of B, Hf, Y micro- alloyed TiAl-based alloy was near lamellar microstructure in which α2/γ lamellar colonies were refined. The XRD analysis shows that, besides % and ,,/phase, β（B2）, Y2O3, YA12 were also included in the as- cast microstructure. The analysis of SEM combined with EDS shows that the β（B2） phase was distributed near the lamellar colonies grain boundaries, granular Y203 and YA12, and granular or strip boride existed in grains and grain boundaries . After heat treatment at 1260℃ for 20h, at 900℃ for 30min and subsequent air-cooling, the duplex microstructures composed with thin α2/γ lamellar and γ equiaxed axis grains were obtained in the alloy, the β （B2） phase has been basically eliminated, simultaneously the YAI： has disap- peared, and meanwhile Hf-rich Y2O3 and Nb-rich titanium boride phases formed.
出处
《沈阳航空航天大学学报》
2013年第1期66-70,共5页
Journal of Shenyang Aerospace University
基金
国家自然科学基金项目(项目编号:50801047)
关键词
高铌TIAL合金
多组元微合金化
热处理
high Nb containing TiAl alloy
multi-component micro-alloying
heat treatment
