高温钛合金Ti-60粉末的制备和表征

采用感应熔炼气体雾化法制备了掺杂稀土Nd的高温钛合金Ti--60粉末。 结果表明, 在制备过程中合金元素几乎没有烧损, 增氧量小于100×10^-6; 粉末的平均粒度(d₅₀)约为100 μm, 满足正态分布, 雾化气体的压力增大则粉末的粒度减小; 粉末的形貌大多呈球形, 只有少量的形状不规则; 部分粉末是空心的, 其比例随着粉末粒度的增加而增大; 粉末表面有明显的凝固特征, 具有清晰的二次枝晶; 随着Nd含量的增加, 粉末表面富Nd稀土相的析出增加; 粉末由针状 α' 马氏体组织构成, 当真空退火温度超过700℃时马氏体开始微量分解, 当温度升高到850℃时马氏体大量分解。

Preparation and Characterization of High Temperature Titanium Alloy Ti–60 Powders

The high temperature titanium alloy Ti–60 powder was prepared by Electrode Induction Melting Gas Atomization (EIGA) method. The variation in chemistry between nominal composition and powder was minimal and the increment of oxygen during gas atomization was less than 100×10⁻⁶, which insured the alloy composition and purity of the powder. The powder size distribution followed Gaussian distribution and the medium diameter (d50) was about 100 μm, which was decreased with the increasing of argon gas pressure during atomization process. The powder was nearly spherical and some powder particles were irregular. Some powders were hollow and the percentage of the hollow powder increased with the increase of powder diameter. The powder surface showed an obvious characteristic of solidification with distinct secondary dendrite and the rich–neodymium phase became apparent with the increase of neodymium content. The powder microstructure was composed of α martensite phase formed upon the high rate solidification process, which decomposed at 700^oC  micro–contently and at 850^oC heavily.