Effect of mechanical alloying on combustion synthesis of MoSi2

Abstract

Characteristics of the combustion synthesis of MoSi2 using elemental Mo and Si powder mixtures prepared by mechanical alloying were investigated. The mechanical alloying resulted in powders of pseudolamellar structure and a partial conversion of the elemental powders to hexagonal MoSi2 phase. Combustion reaction of the mixture was ignited around 670 degreesC, which is much lower than that with the powder prepared by low-energy ball milling. A mathematical model was developed to demonstrate the possibility of the ignition of the combustion reaction of the lamellar structure via a solid-state diffusional process. On the basis of model, effects of mechanical alloying time on the ignition temperature and combustion temperature are discussed.