Article ID Journal Published Year Pages File Type
1599630 Intermetallics 2016 9 Pages PDF
Abstract

•DS MoSi2/Mo5Si3/Mo5Si3C composites exhibit a fine script lamellar microstructure.•Mo5Si3C forms interconnected networks and divides MoSi2 matrix into small regions.•The orientation relationship is selected to effectively accommodate lattice misfits.•Three-phase composites have higher yield strength than two-phase counterpart.

The microstructures, orientation relationships, and high-temperature deformation behavior of directionally solidified (DS) ingots of MoSi2/Mo5Si3/Mo5Si3C three-phase eutectic composites were investigated. The DS three-phase composites exhibit a fine and homogeneous script lamellar microstructure. Mo5Si3 and Mo5Si3C individually form interconnected networks that extend in the growth direction (GD) of the MoSi2 matrix and maintain [11¯0]MoSi2, [001]Mo5Si3[001]Mo5Si3, and [0001]Mo5Si3C[0001]Mo5Si3C approximately parallel to the GD. High-temperature strength is higher in the DS three-phase composite than in the binary two-phase counterpart, especially below 1200 °C. This is mainly because of MoSi2 matrix refinement and the presence of the strengthening phase Mo5Si3C. The observed orientation relationship between component phases is discussed in relation to lattice misfits.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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