显微组织对近α型TG6钛合金高温蠕变变形行为的影响  

Effect of microstructure on creep deformation behavior of near-alpha titanium alloy TG6

作　　者：段锐[1] 张华 蔡建明 黄旭[1] 曹春晓[1] 

机构地区：[1]北京航空材料研究院,北京100095 [2]贵州安大航空锻造有限责任公司,安顺561005

出　　处：《中国有色金属学报》2010年第B10期11-15,共5页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2007CB613803)

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α_2相和硅化物沉淀析出对蠕变抗力的作用,均匀析出的α_2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。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 ofbasketweave structure reduces. On the contrary, the creep resistances of duplex and equiaxed structures improve, which may be due to the different roles of α2 phase and silicide precipitation on the creep resistance. The homogeneous precipitated α2 phase may improve the resistance, while the silicide precipitation may result in reduction of creep resistance due to the depletion of Si in a matrix. The steady state creep deformation of TG6 titanium under 600℃ and 200 MPa is mainly controlled by dislocation climbing.

关 键 词：高温钛合金 蠕变行为 位错攀移 

分 类 号：TG146[一般工业技术—材料科学与工程]