Formation mechanism of MoSi2 in presence of copper by combustion synthesis: study in thermal explosion mode

The effect of copper addition on the formation mechanism of MoSi 2 through combustion synthesis (thermal explosion mode) from elemental powder mixtures was evaluated. It was proposed that in the presence of copper, the reaction starts by forming a low melting point and eutectic melt of Cu-Si, and proceeds by the dissolution of Mo in the melt. The effect of copper addition on the ignition and combustion temperatures was also investigated. It was found that by increasing the copper amount, the ignition temperature decreases but the combustion temperature increases. This effect was also attributed to the formation of low temperature eutectic melt which causes the initiation of the reaction at lower temperatures. This melt also increased the mass and heat transfer rate, which leads to a higher reaction rate and combustion temperature.