利用透射电子显微镜研究了具有近全片层组织的Ｔｉ－４７Ａｌ－２Ｍｎ－２Ｎｂ合金在液氮（７７Ｋ）温度下变形的微观结构．结果表明：在层片内部只存在（１／２）〈１１０］普通位错，但是在γ晶粒内部除了存在（１／２）〈１１０］普通位错外，也存在〈１０１］和（１／２）〈１１２］超位错．另外，在γ晶粒内发现了位错被钉扎后形成的层错偶．说明在该温度下，合金形变不仅受超位错的运动和层错偶控制，而且受（１／２）〈１１０］普通位错的控制． The microstructure of Ti-47Al-2Mn-2Nb alloy with nearly full lamellar structure deformed at liquid nitrogen (77K) temperature was investigated by transmission electron microscopy. The results show that there are only (1/2) <110] ordinary dislocations in the interior of the ply, but there are also <101] and (1 / 2) <112] Super-dislocations. In addition, layer mismatches formed after pinning the dislocations were found in the γ grains. It shows that at this temperature, the deformation of the alloy is not only controlled by the motion of super-dislocation and the layer mismatch, but also controlled by the general dislocation of (1/2) <110].