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在７７～６２３Ｋ对淬火态ＴＣ４合金进行了热循环试验，测定了合金热循环后的硬度，并与６２３Ｋ时效合金的硬度进行了对比；还观察了拉伸试样断口形貌。结果表明：热应力能加速亚稳相的分解，使合金中的位错密度升高，层错和形变孪晶的数量增多；循环温度场作用下淬火态合金拉伸试样断口由韧窝型断裂向韧窝和撕裂棱混合型断裂转变。
The thermal cycling test was carried out on the quenched TC4 alloy at 77 ~ 623K. The hardness of the alloy after thermal cycling was measured and compared with the hardness of the 623K aging alloy. The fracture appearance of the tensile specimen was also observed. The results show that thermal stress can accelerate the decomposition of metastable phase, increase the dislocation density and increase the number of strata and deformation twins in the alloy. The fracture of the quenched alloy tensile specimen under cyclic temperature field consists of dimple Fracture to dimple and tear edge mixed fracture transition.