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采用溶胶喷雾干燥-热还原法制备了50W-35Ni-15Fe(质量分数,%,下同)纳米晶复合粉末。利用X射线衍射及微区组织的能谱(EDAX)分析,揭示了纳米晶W-Ni-Fe复合粉末及其烧结过程中的固溶特性。研究发现:纳米晶50W-35Ni-15Fe复合粉末中,W在γ-(Ni,Fe)相中的固溶度达到了15%,Ni、Fe元素在W中的固溶度达到了2.4%,形成了超饱和固溶体;随着温度的升高,W的超饱和固溶体W(Ni,Fe)发生Ni、Fe元素的脱溶。而W在γ-(Ni,Fe)相中的固溶度随温度的升高而进一步增加,在1300℃以后基本维持在29%左右;稀土La的加入在低温阶段对W在γ-(Ni,Fe)相中的固溶度影响不大,在1200℃以上使固溶度有一定的降低。
50W-35Ni-15Fe (mass fraction,%, same below) nanocrystalline composite powder was prepared by sol-gel spray drying-thermal reduction method. X-ray diffraction and EDAX analysis revealed that the nanocrystalline W-Ni-Fe composite powder and its solid solution during sintering process. The results show that the solid solubility of W in γ- (Ni, Fe) phase reaches 15% in nanocrystalline 50W-35Ni-15Fe composite powder, and the solubility of Ni and Fe in W reaches 2.4% Forming a supersaturated solid solution. With the increase of temperature, W, Ni and Fe elements dissolve in the supersaturated solid solution W (Ni, Fe). However, the solid solubility of W in γ- (Ni, Fe) phase increases further with the increase of temperature and remains about 29% after 1300 ℃. The addition of rare earth La , Fe) phase has little effect on the solid solubility, above 1200 ℃ to make a certain degree of decrease in solid solubility.