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通过光学显微镜、扫描电镜及拉伸性能测试等方式研究了固溶温度对一种新型亚稳β钛合金(Ti-3Al-8V-4Mo-4Cr-4Zr-2Nb-2Fe)组织与拉伸性能的影响。结果表明,在660~720℃范围内,随着固溶温度的升高,实验合金组织中的初生α相数量减少,β基体尺寸增大,抗拉强度降低,塑性升高。合金经460℃低温时效处理后,组织中的次生α相以短棒状和长针状两种形态析出,前者在初生α相密集区析出,后者在β晶内析出。随着固溶温度的升高,次生α相的厚度增加,长宽比减小,致密度降低,形态由针状向短棒状转变,同时,初生α相的含量不断减少;当固溶温度升至740℃时,晶内已无初生α相析出。合金经720℃×30 min/AC+460℃×12 h/AC处理后,具有良好的强韧性匹配。720℃为该合金的最佳固溶温度。
The effects of solution temperature on the microstructure and tensile properties of a new metastable β-titanium alloy (Ti-3Al-8V-4Mo-4Cr-4Zr-2Nb-2Fe) were investigated by optical microscopy, scanning electron microscopy and tensile testing. influences. The results show that in the range of 660-720 ℃, as the solution temperature increases, the amount of primary α phase decreases, the size of β matrix increases, the tensile strength decreases and the plasticity increases. After the alloy was aged at 460 ℃, the secondary α phase precipitated in the form of short rod and long needle. The former precipitated in the primary α phase and the latter precipitated in the β crystal. As the solution temperature increases, the thickness of the secondary α phase increases, the aspect ratio decreases, the densification decreases, and the morphology changes from acicular to short rod. At the same time, the content of primary α phase decreases. Raised to 740 ℃, the crystal has no primary α-phase precipitation. After 720 ℃ × 30 min / AC + 460 ℃ × 12 h / AC, the alloy has good toughness matching. 720 ℃ for the alloy solution temperature.