Alumina containing Cr3C2 of different sizes and compositions of was pressurelessly sintered at 1550°C for 2 h in 1 atm Ar atmosphere. The fracture toughness values of Al2O3/Cr3C2 composites were consistently observed to be higher than that of monolithic alumina. An optimum toughness of 5.9 MPa m1/2 was obtained for the 30 vol.% Cr3C2(2 μm) / Al2O3 composite. Small Cr3C2 (2 μm) particles had a more positive toughening effect than did large Cr3C2 (7 μm) particles. Cracks were observed to radiate from the Cr3C2 particles. Coalescence and necking of Cr3C2 were observed in composites with high Cr3C2 contents. Pores due to the pull out of Cr3C2 particles were also observed. The observed toughening effects were attributed to the mechanisms of crack deflection and microcracking. Theoretical toughness was calculated and compared with the experimental results.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics