【摘要】 研究了B2单相区等温锻造Ti-22Al-25Nb(原子分数)合金经不同固溶加时效热处理工艺处理后,其显微组织的演变和力学性能的变化。研究结果表明,随着固溶温度的升高,Ti-22Al-25Nb合金组织中一次板条状O相变短变粗,体积分数减小,有球化的趋势,在随后的时效过程中会析出更多的次生针状板条O相;拉伸强度也随固溶温度升高而增加,塑性略微提高,断裂主要以沿B2晶粒的解理面解理断裂或准解理断裂为主,呈现许多近似层状的解理小刻面,其微观形貌为微孔状的韧窝。更多还原

【Abstract】 The microstructure evolution and mechanical properties of isothermally forged Ti-22 Al-25 Nb( at. %) alloy at B2-phase region during two different heat treatments were investigated. The results indicate that lamellar O phase becomes shorter and coarser, the volume fraction decreases,and tends to be spheroidized with the increasing of solution temperature. And during the subsequent aging process, more secondary O phase is precipitated. The mechanical properties of the Ti-22Al-25 Nb alloy show that the tensile strength and ductility increase with the increasing of solution temperature. The fracture mode mainly consistes of cleavage fracture or quasi-cleavage fracture along B2 grain,and the fracture surface presents a lot of approximate layered cleavage surface,whose microstructure is the micro-porous dimples.更多还原