【摘要】 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。更多还原

【Abstract】 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.更多还原