摘要
Ti-1023合金中初生α相(α_p)的体积分数对材料性能影响较大:在固溶(ST)条件下,α_p相体积分数减少,材料强度降低;在固溶时效(STA)条件下,α_p相体积分数减少,材料强度和断裂韧度(K_(IC))呈升高趋势,但后者增加的趋势没有前者明显.α_p相对材料性能的影响与其体积分数的变化改变亚稳β晶粒内溶质原子浓度和亚稳β晶粒尺寸有关.时效过程中析出的次生α相(α_s)可明显影响材料的力学性能,随α_s的长大和数量的减少强化效应减弱,但K_(IC)和塑性明显提高.对Ti-1023合金,减少α_p相的体积分数、控制合适的α_s相数量和尺寸并尽可能减少连续晶界α相数量与尺寸,可以获得较高的强韧性匹配.
The volume fraction of primary α phase （αp） in Ti-1023 alloy plays the main role in influencing the mechanical properties. Under solution heat treatment （ST） condition, tensile strength decreases with the decrease of the volume fraction of αp; Under solution and aging heat treatment （STA） condition, both the strength and fracture toughness （KIC） exhibit the increase tendency with the decrease of the αp volume fraction, but the increase amplitude for Kic was far less than that for strength. The above results can be explained by the decrease of the αp volume fraction caused the increases of the solute concentration in metastable β phase and the growth of β grain size. The secondary α phase （αs） has obvious effect on improving mechanical strength. With the growth of αs size and the decrease of its amount, the strengthening effect of αs was decreased, but fracture toughness and tensile ductility were obviously improved. The better combination of fracture toughness and tensile strength can be achieved by lowering αp volume fraction, controlling appropriate αs amount and its size and reducing the amount and size of continuous grain boundary α phase.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第11期1129-1137,共9页
Acta Metallurgica Sinica
关键词
TI-1023合金
初生Α相
次生α相
拉伸
断裂韧性
Ti-1023 alloy, primary α phase, secondary α phase, tensile property, fracture toughness
