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利用放电等离子烧结技术(SPS)制备了生物医用Ti-24Nb-4Zr-8Sn合金,研究了固溶温度对合金显微组织和力学性能的影响。结果表明:合金在相变点下(750℃)固溶后,显微组织主要由β相、初生α相和次生α″相组成,当固溶温度升至相变点附近(775℃)时,β晶粒尺寸显著增大,晶界初生α相厚度和数量均明显减小,β晶粒上弥散分布着大量细针状与颗粒状的次生α″相;随着固溶温度的进一步升高,晶界α相厚度和数量减小并逐渐连续呈网状,β晶粒内部次生α″相不均匀析出且数量逐渐减少;与烧结态相比,合金强度和弹性模量随固溶温度的提高呈先升高后降低趋势,而塑韧性逐渐提高。
Biomedical Ti-24Nb-4Zr-8Sn alloy was prepared by spark plasma sintering (SPS), and the effect of solution temperature on the microstructure and mechanical properties of the alloy was investigated. The results show that the microstructure of the alloy is mainly composed of β phase, primary α phase and secondary α phase after solution treatment at 750 ℃. When the solution temperature rises to near the transformation point (775 ℃) , The grain size of β increased significantly, the thickness and number of primary α phase in grain boundaries decreased obviously, and a large number of fine acicular and granular secondary α “phases dispersed on β grains. With the increase of solution temperature Further increasing, the thickness and amount of the α phase in the grain boundary decreased and gradually became reticular, the secondary α ”phase in the β grain was non-uniformly precipitated and the number decreased gradually. Compared with the sintered state, the strength and the elastic modulus of the alloy The increase of solution temperature first increases and then decreases, while the plasticity and toughness gradually increase.