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在扫描电镜和Ｈ－８００透射电子显微镜上，研究了Ｔｉ３Ａｌ－Ｎｂ（Ｔｉ－２４Ａｌ－１４Ｎｂ－３Ｖ－０．５Ｍｏ）（ａｔ．％）合金不同组织状态下的室温拉伸变形机制。利用双倾技术和双束条件下ｇ．ｂ＝０不可见判据，分析了合金中具有Ｄ０１９结构的α２相和ｂｃｃ结构的Ｂ２相在拉伸变形后的位错类型和滑移系。结果表明，初生α２相体积分数高时，α２相内部出现致密且平行的滑移带，ａ型位错在基面｛０００１｝上形成大量亚晶界和六角位错网络，使初生α２晶粒产生形变，并且协调了晶界的变形。另外，还有ａ型刃位错及少量ｃ型位错在柱面｛１０１０｝上滑移，初生α２相体积分数低时，基体Ｂ２相上形成宽而长的滑移带，ａ／２〈１１１〉刃型位错在｛１１０｝面上滑移是Ｂ２相的主要变形模式。
The tensile deformation mechanism of Ti3Al-Nb (Ti-24Al-14Nb-3V-0.5Mo) (at.%) Alloy under different microstructures was investigated by SEM and H-800 transmission electron microscopy. Using double dip technology and double beam conditions g. b = 0 invisible criterion, the dislocation types and slip systems of B2 phase with α2 phase and bcc structure with D019 structure in the alloy after tensile deformation were analyzed. The results show that dense and parallel slip bands occur in the α2 phase when the volume fraction of primary α2 phase is high, and a-type dislocations form a large number of subgrain boundaries and hexagonal dislocation networks on the base {0001} Produce deformation, and coordinate the deformation of grain boundaries. In addition, a type of edge dislocation and a small amount of c-type dislocation glide on the cylinder {1010}, the volume fraction of the primary α2 phase is low, the matrix B2 phase to form a wide and long slip band, a / 2 < 111> edge dislocation Slip on the {110} plane is the major deformation mode of the B2 phase.