Ti_2AlNb合金近β等温锻造组织与性能研究  

Microstructure and Properties of the Near-β Isothermally Forged Ti_2AlNb Based Alloy

作　　者：张建伟[1] 梁晓波[1] 程云君[1] 曾卫东[2] 薛强 

机构地区：[1]钢铁研究总院,北京100081 [2]西北工业大学,陕西西安710072 [3]中航工业宏远锻造厂,陕西三原713801

出　　处：《稀有金属材料与工程》2014年第5期1157-1160,共4页Rare Metal Materials and Engineering

摘　　要：对成分为Ti-22Al-25Nb(at%)的Ti2AlNb合金在近β等温锻造与锻后热处理过程中的组织转变规律及其对力学性能的影响进行了研究。结果表明,经近β等温锻造/空冷后,合金获得由少量均匀分布的α2相等轴颗粒和转变B2相基体(基体中含有排列杂乱的细小O相板条)构成的双态组织。锻后经960℃及其以上温度处理/水冷的合金再经时效处理后,依然具有双态组织;而经940℃及其以下温度处理/水冷的合金再经时效处理后,则获得由少量均匀分布的α2相等轴颗粒、粗大和细小两种尺寸的O相板条以及B2相基体构成的三态组织。三态组织中的粗大板条造成合金的强度有所下降,但塑性、持久、断裂韧性和疲劳性能均有不同程度的提高,其各项力学性能的匹配好于双态组织。The microstructure evolution and mechanical property of Ti-22Al-25Nb （at%） alloy after near-fl isothermal forging and heattreatment were studied. The results indicate that the duplex microstructure, which is consisted of a small amount of equiaxed a2 particlesand B2 matrix （containing fine lath O） appears after near-p isothermal forging and then air cooling. And this kind of duplex microstructurestill exists after 960 ℃ solution treatment with water cooling and then aging. However, when the alloy is treated at 940 ℃ followed bywater cooling and then aged, the tri-morphology microstructure, which is consisted of a small amount of equiaxed a2 particles, coarse andfine lath O and B2 matrix, occurs. The strength of the alloy is reduced owing to the coarse lath O, while the ductility, endurance, fracturetoughness and fatigue behavior are all improved which is of better matching than the duplex microstructure.

关 键 词：Ti2AlNb合金 近Β锻造 三态组织 性能匹配 

分 类 号：TG319[金属学及工艺—金属压力加工]