摘要
研究热等静压温度对定向层片组织常规铸造Ti Al合金层片分解程度和室温拉伸性能的影响,以期优选出适于定向层片组织的热等静压温度。结果表明:在1250℃热等静压处理,析出过多的等轴γ晶粒,降低了该合金的室温拉伸强度;在1290℃热等静压处理,发生层片粗化和生成随机取向二次层片,破坏了取向一致性,降低了室温拉伸性能的稳定性。在1270℃等静压处理,等轴γ晶粒析出量较少,且未见明显的层片粗化和二次层片,所得组织保持较好的层片组织完整性和取向一致性,并表现出最佳的室温强度、塑性和性能稳定性。确定适于定向层片组织铸造Ti Al合金的热等静压温度是1270℃。
The effect of hot isostatic pressing temperature on lamellar breakdown behavior and RT tensile properties was studied for a cast Ti Al based alloy with directional lamellar microstructure by conventional casting,in order to optimize the temperature of hot isostatic pressing（ HIP） for the special lamellar microstructure. After HIP at 1250 ℃,excessive equiaxed γ grains were precipitated along the colony boundary or in the colony,which resulted in reduction of tensile strength at RT. After HIP at 1290 ℃,breakdown of lamellar was occurred by coarsening of lamellar and formation of secondary lamellar with random orientation. Formation of the secondary lamellar resulted in instability of tensile properties at RT. After HIP at 1270 ℃,less equiaxed γ grains were precipitated and secondary lamellar did not generated,so the better integrality of lamellar and uniformity of lamellar orientation were kept by the microstructure obtained,and also the best tensile properties and good stability were achieved. Finally,HIP at 1270 ℃ is good for the directional lamellar microstructure.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2016年第1期7-11,共5页
Journal of Aeronautical Materials
关键词
铸造TIAL合金
定向层片
热等静压
二次层片
拉伸性能
cast TiAl alloy
directional lamellar
hot isostatic pressing
secondary lamellar
tensile properties
