【摘要】 在Ｈ～８００透射电子显微镜上，利用双倾技术和双束条件下ｇ·ｂ＝０不可见判据，研究了Ｔｉ３Ａｌ－Ｎｂ合金中具有Ｄ０１９结构的α２相在室温和高温时的拉伸变形机理。结果表明，ａ型位错在基面｛０００１｝上形成六角位错网络，在柱面｛１０１０｝上滑移是α２相的主要变形模式，合金高温下塑性的提高与α２相中ｃ＋ａ／２型位错对的开动有关。更多还原

【Abstract】 The mechanism of tensile deformation of α 2 phase (D0 19 in Ti 24Al 14Nb 3V 0 5Mo alloy at room temperature and 700℃ was investigated in accordance with g·b =0 invisibility criterion in a H 800 TEM equipped with a side entry gonimeter stage capable of ±45° tilt on the X or Y axis operating under two-beam conditions The results indicate that a type edge dislocations forming hexagonal dislocation networks on basal planes {0001}and slip of a type dislocations on prismatic planes {1010} are mainly deformation modes of α 2-phase, higher plasticity of the alloy at 700℃ is connected with the slip of c+a /2 type dislocation in α 2 phase更多还原