TC18钛合金的微观组织和力学性能

Microtructure and mechanical properties of TC18 Titanium alloy

摘要:

本研究使用真空自耗炉制备出Ti-5Al-5Mo-5V-1Fe-1Cr钛合金，然后进行了热机加工和热处理。本文对热处理后材料的微观组织和力学性能进行了研究。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。拉伸试验中试样表现出了良好的强度和塑性，不过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。

Abstract:

Ti-5Al-5Mo-5V-1Fe-1Cr Ti alloy is fabricated via consumable vacuum arc-remelting furnace in this work, and then is subjected to thermo-mechanical processing and heat treatment. The microstructural characteristics and tensile properties of the heat-treated material are investigated. Primary α dispersing in β phase shows as spheroidization, near equiaxed, plate-shaped and rod-shaped after heat treatment. This is associated with boundary segregation of α grain. The material has a good combination of strength and plasticity during tensile test. However, the value of σy /σb of the material reaches 0.95. It is suggested that the grain boundary absorb dislocations during tensile test. Therefore, the dislocation strengthening increases very slowly. This is the primary reason for the material to obtain high value of σy /σb.