Mechanical properties and microstructure of Al/(TiC + TiB2) composite fabricated by spark plasma sintering

In this research, the mechanical properties and microstructure of the Al matrix composites reinforced with TiC + TiB2 particles (in contents of 10, 20, 30 and 40 vol%.) were investigated. The samples were prepared by mechanical alloying and spark plasma sintering methods under the pressure of 50 MPa and sintering temperature of 465 degrees C for holding time of 15 min. The XRD patterns showed the formation of TiC and TiB2 compounds from Ti and B4C initial powders and also demonstrated that the powders obtained from the ball milling process did not contain any additional compounds or impurities. The SEM images revealed the homogeneous distribution of particles (TiC + TiB2) in the Al matrix. The mechanical properties, such as hardness, Young's modulus, yield, and tensile strengths were measured by the nano-indention test. Nano-indention test showed that 20 vol% of reinforcement was optimum content of improved mechanical properties, so that in the content of 20 vol%, the Vickers hardness, Young's modulus, yield, and tensile strengths were improved about 135, 45, 195 and 194%, respectively.