Structural and mechanical properties of Al-SiC-ZrO2 nanocomposites fabricated by microwave sintering technique

Abstract

In the present study, Al-SiC-ZrO2 nanocomposites were developed and characterized. Towards this direction, the aluminum (Al) matrix was reinforced with nano-sized silicon carbide (SiC) and zirconium dioxide (ZrO2), and the mixture was blended using ball milling technique. The blended powder was compacted and sintered in a microwave sintering furnace at 550? C with a heating rate of 10? C/min and a dwell time of 30 min. The amount of SiC reinforcement was fixed to 5 wt.%, while the concentration of ZrO2 was varied from 3 to 9 wt.% to elucidate its effect on the microstructural and mechanical properties of the developed nanocomposites. Microstructural analysis revealed the presence and uniform distribution of reinforcements into the Al matrix without any significant agglomeration. The mechanical properties of Al-SiC-ZrO2 nanocomposites (microhardness and compressive strength) were observed to increase with the increase in the concentration of ZrO2 nanoparticles into the matrix. Al-SiC-ZrO2 nanocomposites containing 9 wt.% of ZrO2 nanoparticles demonstrated superior hardness (67 ± 4 Hv), yield strength (103 ± 5 MPa), and compressive strength (355 ± 5 MPa) when compared to pure Al and other compositions of the synthesized composites. Al-SiC-ZrO2 nanocomposites exhibited the shear mode of fracture under compression loadings, and the degree of deformation was restricted due to the work hardening effect. The appealing properties of Al-SiC-ZrO2 nanocomposites make them attractive for industrial applications. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.