Microstructure and mechanical properties of hot isostatically pressed Cr2O3/5 vol% Mo composites

Dense Cr2O3/5 vol% Mo composites (99.3% of theoretical) consisting of fine Cr2O3 matrix grains (∼0.35 μm) have been fabricated by hot isostatic pressing (1200°C/2 h/196 MPa) using a mixture of sol-gel-derived Cr2O3 and commercially available Mo powders. Nanoscale Mo particles are dispersed either in the boundaries of grains or in the matrix, while submicrometer-sized particles are located in the grain boundaries. They are a strengthening and toughening agent. The strength and toughness of the composites are 620 MPa and 4.6 MPa·m1/2, respectively.