Dry sliding wear behavior of SiC-B4C reinforced AZ80 hybrid composites fabricated through a semi-solid stir casting process

• Homogeneous distribution of ceramic particulates in the Mg matrix is achieved by a low-cost semi-solid stir-casting process. • The present research focuses on the impact of wear testing conditions and amount of reinforcement quantity on the dry sliding wear performance of AZ80 alloy and AZ80/SiC-B 4 C composites. • Among the developed composites, the (AZ80 + 9% SiC + 3% B 4 C) composite exhibits superior wear resistance. • The worn surface morphology of the AZ80 alloy and the hybrid composites reveals a series of grooves, abrasion, delamination and plastic deformation at different tested conditions. The wear behavior of AZ80 alloy and the hybrid composites reinforced with varying SiC (3, 6, and 9 wt.%) along with 3 wt.% B 4 C was examined under different applied loads (10–20 N) and sliding speeds (0.05–0.2 m/s). Due to a uniform distribution of SiC and B 4 C particles in the composite, microhardness evaluations show that the composite's hardness increases as reinforcement content increases. Maximum hardness achieved for (AZ80 + 6% SiC + 3% B 4 C) composites is 96.60 HV. Worn surface analyses of unreinforced and hybrid composites were examined to identify the dominant wear mechanisms according to the wear conditions and the reinforcement content. This was accomplished by recording wear rates and friction coefficients throughout the wear tests, as well as characterizing the worn surfaces through investigations using energy dispersive X-ray spectroscopy and scanning electron microscopy. Under a 10 N load, AZ80 exhibits a coefficient of friction of 0.70, while the (AZ80 + 9% SiC + 3% B₄C) composite showed the lowest coefficient of 0.48 among all the hybrid composites. Results showed that oxidation, abrasion, delamination and plastic deformation were the dominant mechanisms caused by thermal softening and melting. The wear rate of unreinforced alloy and the composites increases at different normal loads of (10–20 N) due to the increase in microhardness according to Archard’s law. On the other hand, the wear rate decreased at various speeds (0.05–0.2 m/s) is also due to the transition from abrasion to plastic deformation. Among the developed composites, (AZ80 + 9% SiC + 3% B 4 C) exhibits excellent wear resistance at various load and sliding speeds. Current work indicates that hybrid Mg matrix composites can be considered as an outstanding material where high strength and wear-resistant components are used primarily in the aerospace and automotive engineering sectors.