Microstructures of PM Ti-45Al-10Nb alloy fabricated by reactive sintering  

反应烧结制备Ti-45Al-10Nb合金的显微组织（英文）

作　　者：孙宏飞[1] 李学问[2] 房文斌[1,2] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001 [2]哈尔滨理工大学材料科学与工程学院,哈尔滨150040

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第5期1454-1459,共6页中国有色金属学报（英文版）

摘　　要：Powder metallurgy Ti-45Al-10 Nb alloys was successfully fabricated by reactive sintering of milled powders at 1350 °C for 2 h in vacuum. The microstructure, in particular, constituent phases, grain size, precipitates of the product was investigated in detail. The results indicate that a double phase γ＋α2 microstructure containing Ti2 Al C precipitate is obtained under the sintering condition, and the alloy exhibits a fine and homogenous microstructure compared with traditional Ti Al base. In fine grain structure, the average grain sizes for the γ and α2 phases are（2.3±0.05） and（5.6±0.05） μm, respectively. Additionally, numerous dislocations are observed in the alloy, and the dislocation density in γ phase is significantly higher than that in α2 phase. The formation mechanisms of the dislocation in the present alloy were also discussed in detail.对球磨后的粉末在1350°C保温2 h进行反应烧结,制备Ti-45Al-10Nb合金。对烧结坯料的显微组织,尤其对相组成,晶粒尺寸及颗粒的分布进行细致研究。结果表明,在此烧结条件下,材料的显微组织主要由Ti2Al C颗粒强化的双相γ+α2组织组成,相对于传统Ti Al基合金,该合金呈现出细小、均匀的显微组织。在细晶区,γ相和α2相的平均晶粒尺寸分别为(2.3±0.05)和(5.6±0.05)μm。此外,合金中存在大量位错,且γ相中的位错密度远高于α2相中的位错密度,对位错形成机理进行分析。

关 键 词：high Nb-TiAl alloy powder metallurgy microstructure DISLOCATION 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TF124[金属学及工艺—金属材料]