| During mechanical alloying(MA) of ductile materials, it is often found that either welding or fracturing becomes so dominant that both very fine layered structure and homogeneously alloyed powder can not be obtained. For this reason, it is necessary to add an appropriate amount of process control agent(PCA). However, it has not been reported yet how PCA affects the MA process. Hence, the present work investigated the precise role of PCA during MA process. The results showed that carbon atoms in PCA molecules suppress the welding of powders and thereby increase the fracturing as the amount of PCA or the number of carbon atoms in PCA increases. On the other hand, the oxygen atoms in PCA seem to delay the phase transformation kinetics. Therefore, the amount of PCA necessary in mecahnical alloying should be added so that PCA suppresses only severe welding and increases the hardness of soft materials. |
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