J Mater Sci Technol ›› 1999, Vol. 15 ›› Issue (05): 423-426.

• Research Articles • Previous Articles     Next Articles

Phase Structure Change of Mo-Si System during Mechanical Alloying

Shaojun LIU, Xuanhui QU, Zhijiang LIU, Baiyun HUANG   

  1. State Key Laboratory for Powder Metallurgy, Central South University of Technology, Changsha 410083, China
  • Received:1998-08-07 Revised:1998-12-14 Online:1999-09-28 Published:2009-10-10
  • Contact: Shaojun LIU

Abstract: The structure of Mo-15.16 Si, Mo-30 Si and Mo-36.3 Si (wt pct) elemental powder mixture during mechanical alloying was studied using electron microscopy and X-ray diffraction. It had been found that, in all the systems under study, silicon disappeared initially during mechanical alloying (MA). In the Mo-Si systems all products were in form of amorphous state after long time milling, but there were different intermediate products. MoSi2 and Mo5Si3 intermetallic compounds in the Mo-30Si and Mo-36.3Si (wt pct) were directly synthesized from elements through inter-diffussion process. The high density of defects and interface of nano-crystallines induced by ball milling would promote the reaction process. Only in the Mo-15.16Si (wt pct) system was Mo(Si) supersaturated solid solution formed as an intermediate product. Schematic free-energy diagram of Mo-Si system based on the thermodynamics was used to analyze the difference among the intermediate state products.

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