【摘要】 研究TG6钛合金在3种显微组织条件下的600℃蠕变变形行为,在600℃,200 MPa的测试条件下,粗晶的网篮组织具有最强的蠕变抗力,而细晶的等轴组织具有最弱的蠕变抗力,双态组织介于中间。经过600℃长期热暴露后,TG6钛合金网篮组织的蠕变抗力有所下降,而双态组织和等轴组织的蠕变抗力反而得以提高,这归因于α₂相和硅化物沉淀析出对蠕变抗力的作用,均匀析出的α₂相可以提高合金的蠕变抗力,而硅化物的析出会使得α基体贫Si,减弱了Si原子气团对位错攀移的阻碍作用,从而导致蠕变抗力的下降。TG6钛合金在600℃,200 MPa下的稳态蠕变变形主要受位错攀移机制的控制。更多还原

【Abstract】 The creep behaviors of three microstructures of TG6 titanium alloy disc forgings at 600℃were studied. Under the condition of 600℃and 200 MPa,the coarse-grain basketweave structure has the highest creep resistance, fine-grain equiaxed structure has the lowest creep resistance,and the duplex structure has a moderate creep resistance. After a long thermal exposure at 600℃,the creep resistance of basketweave structure reduces.On the contrary,the creep resistances of duplex and equiaxed structures improve,which may be due to the different roles ofα₂ phase and silicide precipitation on the creep resistance.The homogeneous precipitatedα₂ phase may improve the resistance,while the silicide precipitation may result in reduction of creep resistance due to the depletion of Si inαmatrix.The steady state creep deformation of TG6 titanium under 600℃and 200 MPa is mainly controlled by dislocation climbing.更多还原