对１０２０、９５０和９００℃空冷的ＴＣ４合金在－１９６～３５０℃间进行了热循环试验，测定了热循环前后的拉伸性能。结果表明：经１０００次热循环后强度上升，塑性下降，合金中的位错密度增大，形变孪晶的数量增多，其中９５０℃空冷合金的强度上升幅度最大，剩余塑性也最大 The TC4 alloy at 1020, 950 and 900 ℃ air-cooled was subjected to thermal cycling at -196 ~ 350 ℃. The tensile properties before and after thermal cycling were measured. The results show that after 1000 cycles of thermal cycling, the strength increases and the plasticity decreases. The dislocation density increases and the amount of deformation twins increases. The strength of 950 ° C air-cooled alloy increases most and the residual plasticity reaches the maximum