TC18钛合金的微观组织和力学性能（英文）

Microstructure and Mechanical Properties of TC18 Titanium Alloy

使用真空自耗电弧炉制备了Ti-5Al-5Mo-5V-1Fe-1Cr(TC18)钛合金,然后进行了热加工和热处理。对热处理后材料的微观组织和力学性能进行了研究。结果表明,TC18合金热处理后,初生α相呈现出球形、近似等轴、盘状以及短棒状等多种形貌,这和α的晶界偏析有关。拉伸试验中合金表现出了良好的强度和塑性,而材料的屈/强比值却高达0.95。这说明拉伸过程中试样位错强化增长相对缓慢。研究认为,拉伸过程中晶界吸收了增殖的位错,这是导致材料高屈/强比的首要原因。

Ti-5Al-5Mo-5V-1Fe-1Cr Ti alloy（TC18） was fabricated via a consumable vacuum arc-remelting furnace, and then subjected to thermo-mechanical processing and heat treatment. The microstructural characteristics and mechanical properties of the heat-treated alloy were investigated. Results show that primary α phase exhibits spherical, near equiaxed, plate- and rod-shaped morphologies after heat treatment. This is associated with boundary segregation of α grain. The alloy presents a good combination of strength and plasticity during tensile test. However, the value of σy/σb of the alloy reaches 0.95. It is suggested that the grain boundaries absorb dislocations during tensile test; therefore, the dislocation strengthening increases very slowly. This is the primary reason for the high value of σy/σb.