【摘要】 研究了两种不同组织的ＴｉＡｌ合金在较低温度下的超塑性行为。结果表明， 原始显微组织对ＴｉＡｌ基合金的超塑性有很大影响， 其中非平衡的热变形态组织在１０７５℃，８×１０－ ５ｓ－ １ 条件下获得了５１７％ 的延伸率，远高于平衡双态组织（３３３％ ）。分析认为， 非平衡态组织中的高的位错密度使其在高温变形过程中容易发生位错缠结， 由此产生的硬化效应能促使缩颈转移， 从而获得高延性。更多还原

【Abstract】 The superplastic behavior of a Ti 46 7Al 2 2Cr(at%) alloy with two different microstructure was investigated under lower temperature(1075℃) The elongation obtained in hot deformed material (517%) was much higher than that in duplex material (333%), which shows that the initial microstructure has great influence on the superplasticity of TiAl based alloy Dislocation network is easy to form in hot deformed material during superplastic deformation because of the high density of initial dislocation and thus strengthened the material In this way, the local necking will be transformed to other area and thus the uniformity of deformation is preserved更多还原