Ti-5.8Al-4.8Sn-2Zr-1Mo-0.35Si-0.70Nd合金中富钕稀土相研究

发布时间：2018-05-08 19:19

  本文选题：快速凝固 + 粉末冶金　； 参考：《稀有金属材料与工程》2015年01期

【摘要】：针对Ti-5.8Al-4.8Sn-2Zr-1Mo-0.35Si-0.70Nd粉末冶金高温钛合金中富钕稀土相的形成、尺寸、分布、形态、长大及结构特征进行了系统研究。结果表明:快速凝固态高温钛合金粉末中稀土相为液态析出相,其尺寸大部分在50~250 nm之间,弥散分布在基体中;晶内稀土相多为球状,晶界稀土相多为椭球状,其长轴平行于晶界;TEM观察到的稀土相的尺寸和分布与理论计算相符合;快速凝固高温钛合金粉末经过700~1000℃/110 MPa/0.5 h热等静压成形后,快速凝固过程中已析出的稀土相尺寸变化不大;同时细小的稀土相从过饱和的基体中大量固相析出;经过1200℃/140 MPa/3 h热等静压成形后,稀土相颗粒尺寸大部分在150~500 nm之间,有明显长大;稀土相的高分辨图像及同心衍射环花样表明,快速凝固高温钛合金粉末中的稀土相由5~10 nm的纳米晶组成,经过1200℃热等静压成形处理后的稀土相仍由纳米晶组成,而且纳米晶的尺寸没有明显变化;但是稀土相的"基体"上明显出现富Sn元素的"第二相"颗粒,结构变得复杂。
[Abstract]:The formation, size, distribution, morphology, growth and structural characteristics of neodymium rich rare earth phase in Ti-5.8Al-4.8Sn-2Zr-1Mo-0.35Si-0.70Nd powder metallurgy high temperature titanium alloy were systematically studied. The results show that the rare earth phase is liquid precipitated phase in solidified solid high temperature titanium alloy powder, and its size is mostly between 50 ~ 250 nm and dispersed in the matrix, the rare earth phase in crystal is mostly spherical, and the rare earth phase in grain boundary is ellipsoid. The size and distribution of rare earth phase observed by TEM with long axis parallel to grain boundary are in agreement with the theoretical calculation, and the rapidly solidified high temperature titanium alloy powder is formed by hot isostatic pressing at 700 鈩，

本文编号：1862711