粉末冶金医用超细晶β型Ti28Nb2Zr8Sn合金的显微组织与力学性能

发布时间：2018-06-09 14:11

  本文选题：粉末冶金 + β型-Ti合金　； 参考：《稀有金属材料与工程》2017年03期

【摘要】：采用机械球磨+放电等离子烧结的方法制备出高强度低模量的超细晶β型Ti28Nb2Zr8Sn合金。XRD和SEM结果表明,60 h球磨后的终态合金粉末经放电等离子烧结后,获得的超细晶块体合金为完全的bcc结构;TEM分析表明,超细晶块体合金中bcc结构的β-Ti晶粒为等轴状,其尺寸为500~1000 nm,远小于铸造法制备同类合金几十微米的晶粒尺寸;力学性能测试表明,随升温速率增大或保温时间缩短,超细晶块体合金的抗压缩强度逐渐增大,弹性模量逐渐减小。在烧结温度为900℃、升温速率为150℃/min且保温时间为0 min的条件下,得到的超细晶块体合金晶粒最细小,其压缩强度达到最大(2675 MPa),对应的断裂应变也最大(0.54),且其弹性模量最低(31.6 GPa);同时,该合金试样的加工硬化指数0.073远高于Ti6Al4V合金,这说明其加工硬化和塑性变形能力远远优于Ti-6Al-4V合金,故能够承受更大的载荷和经历更大的变形,可作为一种优异的生物医用候选材料。
[Abstract]:Ultrafine 尾 -type Ti28Nb2Zr8Sn alloy with high strength and low modulus was prepared by mechanical ball milling spark plasma sintering. The results of XRD and SEM showed that the final alloy powder after 60 h ball milling was sintered by spark plasma. Tem analysis shows that the 尾 -Ti grains of the bcc structure in the ultrafine crystal bulk alloy are equiaxed, and the size is 500 ~ 1000nm, which is much smaller than the grain size of dozens of microns of the same alloy prepared by casting method. The mechanical properties test showed that the compressive strength and elastic modulus of the superfine bulk alloy increased gradually with the increase of the heating rate or the shortening of the holding time. When the sintering temperature is 900 鈩，

本文编号：1999998