Microstructure and phase transformation behavior of Mo–MoSi_2 gradient material  

作　　者：Ying-Yi Zhang Yun-Gang Li Yong-Hong Qi Xue-Feng Shi 

机构地区：[1]State Key Laboratory of Advance Steel Processes and Products,Central Iron and Steel Research Institute [2]College of Metallurgy and Energy, Hebei Union University

出　　处：《Rare Metals》2015年第11期808-813,共6页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. 50474079);Hebei Natural Science Foundation of China (No. E2010000945)

摘　　要：Mo-MoSi2gradient coating on Mo substrate was prepared by siliconizing process,using the polysilicon as silicon atoms.The gradient layer was analyzed by the experimental results,theoretical analysis,and thermodynamic calculation.The silicon,molybdenum content of gradient coating shows a gradual change regulation.The reaction between silicon and molybdenum is most likely to generate Mo5Si3,then MoSi2,finally Mo3Si,but when the silicon content is excessive,the Mo5Si3and Mo3Si will react with silicon and generate MoSi2.The gradient layer is mainly constituted by Si and MoSi2,only about 1/10 gradient layer is constituted by Mo5Si3and Mo3Si,and the stable existences of Mo5Si3and Mo3Si are mainly determined by the silicon content.Along the Mo substrate to the surface of the coating,the phase composition of gradient coating changes as follows:Mo → transition layer,Mo（main phase） + Mo3Si + Mo5Si3→intermediate layer,and MoSi2（main phase） + Mo5Si3+Si→surface layer MoSi2（main phase） + Si,and the experimental temperature has no effect on phase composition of gradient coating.Mo-MoSi2gradient coating on Mo substrate was prepared by siliconizing process,using the polysilicon as silicon atoms.The gradient layer was analyzed by the experimental results,theoretical analysis,and thermodynamic calculation.The silicon,molybdenum content of gradient coating shows a gradual change regulation.The reaction between silicon and molybdenum is most likely to generate Mo5Si3,then MoSi2,finally Mo3Si,but when the silicon content is excessive,the Mo5Si3and Mo3Si will react with silicon and generate MoSi2.The gradient layer is mainly constituted by Si and MoSi2,only about 1/10 gradient layer is constituted by Mo5Si3and Mo3Si,and the stable existences of Mo5Si3and Mo3Si are mainly determined by the silicon content.Along the Mo substrate to the surface of the coating,the phase composition of gradient coating changes as follows:Mo → transition layer,Mo（main phase） + Mo3Si + Mo5Si3→intermediate layer,and MoSi2（main phase） + Mo5Si3+Si→surface layer MoSi2（main phase） + Si,and the experimental temperature has no effect on phase composition of gradient coating.

关 键 词：SILICONIZING Mo–MoSi2 Characteristic of gradient c 

分 类 号：TG174.4[金属学及工艺—金属表面处理]