Effects of alloying elements on plastic deformation of single crystals of MoSi2

Effects of alloying elements on the compression deformation behavior of single crystals of MoSi2 have been investigated in the temperature range from room temperature to 1500°C. The alloying elements studied include V, Cr, Nb and Al that form a C40 disilicide with Si and W and Re that form a C11b disilicide with Si. The addition of Al is found to decrease the yield strength of MoSi2 at all temperatures while the additions of V, Cr and Nb are found to decrease the yield strength at low temperatures (below 800°C) and to increase the yield strength at high temperatures (above 1300°C). In contrast, the additions of W and Re (C11b formers) are found to increase the yield strength at all temperatures. Of the ternary elements investigated, Al and Nb seem to be the most effective in improving the low-temperature deformability of MoSi2 while Re and Nb seem to be the most effective in improving the high-temperature strength, judging from the observed yield strength.