Fabrication and fracture analysis of
MoSi2 matrix composites by mechanical alloying
MoSi2 matrix composites by mechanical alloying
(1. School of Materials Science & Engineering, Gansu University of Technology,
Lanzhou 730050, P.R.China;
2. Department of Materials and Process Engineering, University of Waikoto，
Hamilton 3150, New Zealand)
Lanzhou 730050, P.R.China;
2. Department of Materials and Process Engineering, University of Waikoto，
Hamilton 3150, New Zealand)
Abstract: Four composites, MoSi2+ZrO2, MoSi2+ZrO2(Y2O3), MoSi2+ZrO2+SiC and MoSi2+ZrO2(Y2O3)+SiC are fabricated by mechanical alloying. It is clear that cracks produced on the MoSi2 matrix composites during hardness testing belong to the Palmquist crack system. The value of highest fracture toughness of MoSi2+ZrO2+SiC composite is 7.58?MPa·m1/2, which is nearly three times that of monolithic MoSi2. This can be attributed to well-distributed ZrO2 and SiC particles along the boundaries of very fine MoSi2 grains.
Key words: mechanical alloying; composites; fracture toughness; MoSi2; ZrO2; Y2O3