采用扫描电子显微镜对β锻TC17钛合金的时效析出行为进行研究,并以拉伸性能和断裂韧度试验表征不同时效处理对其力学性能的影响.研究结果表明:经两相区固溶+不同时效温度热处理后,α相在β相基体上析出、形核、长大.随着时效温度的升高,次生α相含量逐渐降低且分布不弥散,抗拉强度线性下降,塑性升高,断裂韧度线性升高.经630℃不同保温时间的时效,短时间次生α相呈针状,随着保温时间的延长,次生α相厚度d从42nm粗化至138nm,含量ωa从12.6%下降至4.5%.抗拉强度Rm与次生α相厚度、含量呈Rm=1.01ωa-0.95d+1274.1关系变化.次生α相的厚度降低和含量增加均能使抗拉强度提高,塑性和断裂韧度降低.%Scanning electron microscopy was employed to investigate the aging precipitation behavior of beta process TC17 titanium alloy. Tensile properties and fracture toughness were used to characterize the effect of different aging treatment on mechanical property. The results show that the secondary α phase was nucleated, precipitated and grew on the β phase ma-trix. The fraction of secondary α phase and tensile strength decreased, secondary α phase did not diffuse and fracture toughness increased with the increase of aging temperature after solution in two phase region. The tensile strength linearly decreased, plasticity reduced and fracture toughness linearly increased. The secondary α phase was acicular after aging in a short time at 630℃. The thickness of secondary α phase (d) was coarsened from 42nm to 138nm and fraction (ωa) decreased from 12.6% to 4.5% which can increase the tensile strength, reduce the plasticity and fracture toughness. The relationship between the ten-sile strength Rmand the thickness and fraction of secondary α phase was Rm=1.01ωa-0.95d+1274.1.
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