二元合金超微粉末中化合物相生成规律的研究

Formation Regularities of Compound Phases in Ultrafine Powders of Binary Alloys with Simple Phase Diagram

采用感应加热式的气相蒸发法制备了 Mg- Sb,Bi- Mg,Pb- Mg,Mg- Zn和 Sb- Zn五种合金的超微粉末 ,研究了超微粉末中的相生成规律及粉末粒子的形貌和组织特征 .在 5种合金的超微粉末中均未出现在其合金相图上不存在的化合物相或固溶体相 .在 Mg- Sb合金超微粉末中生成了β-Mg3Sb2 高温相 ,在 Bi- Mg合金超微粉末中生成了 γ- Mg3Bi相 ,在 Mg- Zn合金超微粉末中生成了ε- Mg Zn2相 ,在 Sb- Zn合金超微粉末中生成了 Sb Zn,Sb3Zn4 和 Zn3Sb2 化合物相 ;对于在相图上同时存在固溶体相和化合物相的 Pb- Mg合金 ,超微粉末中只生成了β- Mg2 Pb相 ,未发现固溶体相 .各种合金超微粉末粒子的形貌与相应的纯金属超微粉末的形貌不同 ,形状不规则 ,表面粗糙 ,含有化合物相的粒子衬度不均匀 。

The ultrafine powders of five alloy systems with simple phase diagram,Mg Sb,Bi Mg,Pb Mg,Mg Zn and Sb Zn were prepared by gas evaporation process with induction current as the heating source. The formation regulation of the phases in the as prepared ultrafine powders and the morphology and structure of the particles were investigated. The results show that there didn't form new phases which don't appear at the phase diagram. The high temperature compound phase β Mg 3Sb 2 is formed in the ultrafine powder of Mg Sb alloy; for Bi Mg alloy, compound phase γ Mg 3Bi is formed; for Mg Zn alloy, compound phase ε MgZn 2 is formed; for Sb Zn alloy,compound phasesSbZn,Sb 3Zn 4 and Zn 3Sb 2 are formed.For Pb Mg alloy with both solid solution phases and compound phase in its phase diagram, only compound phase ε Mg 2Pb is formed in its ultrafine powders. The morphology of the as prepared ultrafine powders are irregular with rough surface, which is different from that of the corresponding pure metals. There is inhomogeneous diffraction contrast in the particles with compound phase.