Commercial-grade Si3N4-TiN composites with 0, 10, 20, and 30 wt% TiN content have been characterized. Submicrometer grain-size Si3N4 was reinforced with fine TiN grains. Density, Young's modulus, coefficient of thermal expansion, and fracture toughness increased linearly with TiN content. Increased strength was observed in the Si3N4+20 wt% TiN, and Si3N4 + 30 wt% TiN composites. Fractography was used to characterize the different types of fracture origins. Improvements in toughness and strength are due to residual stresses in the Si3N4 matrix and the TiN particles. A threefold improvement in dry wear resistance of the Si3N4 + 30 wt% TiN composite over the Si3N4 matrix was observed.