Microstructure evolution and mechanical properties of high fraction Al3BC/Al composites fabricated by a reactive hot pressing sintering process

In this work, Al3BC/Al composite with Al3BC fraction of 50 % (50-Al composite) was fabricated by a reactive hot pressing sintering process. Microstructure evolution of the composite with different sintering parameters has been systematacially investigated. Sub-micron Al3BC particles are in situ synthesized and distributed uniformly in the Al matrix. The mechanical properties of the 50-Al composite has been characterized by nanoindentation and micropillar compression tests. The hardness and elastic modulus of the 50-Al composite can reach up to 4.79 GPa and 138.7 GPa, respectively. The micropillar compressive strength of the composite is measured to be 1234 MPa with a shrinkage rate of 17.5 %. The excellent strengthening effect of Al3BC particles on Al matrix is also revealed. The Zigzag slip bands observed on the compressed pillars indicate a impeding effect of Al3BC on the slip process, which contributes to the high mechanical properties of 50-Al composite. •High fraction Al3BC/Al composite was fabricated by a reactive hot pressing sintering.•The ultrahigh strength and modulus of the composite has been fulfilled.•The deformation behavior of the composite is revealed by micropillar compression.