Production and Functional Characteristics Enhancement of AZ91 Alloy Composite by Mixing a PAN-Based Carbon Fiber and Nano Silicon Carbide Particles
摘要
The magnesium alloy (AZ91) composites were developed by using nano ceramic particles via a liquid-state process, which showed better grain refinement, improved load-carrying capacity, and higher hardness. However, higher ceramic particles in magnesium alloy lead to a significant enhancement in hardness, resulting in crack propagation and limiting the overall functional properties, including ultimate tensile strength, yield strength, and impact toughness of the composites. This research addresses the above research gap and enhances the overall mechanical properties of the AZ91 alloy composite by using a 2 wt% short Polyacrylonitrile (PAN)-based carbon fiber and various wt% of nano silicon carbide (SiC) particles via ultrasonic-assisted semisolid stir cast production. The argon gas was supplied throughout the process to limit oxide formation. The effectiveness of the composite processing and contribution of hybrid reinforcement on microstructure, grain size, porosity, and mechanical properties of the AZ91 alloy composites is evaluated. The ultrasonic-assisted semisolid stirrer process breaks the dendrite boundary layer, restricting the grain boundary growth, and leads to homogeneous reinforcement distribution. Moreover, nano-SiC leads to a number of nucleation sites, and PAN-based carbon fiber makes a strong interaction with the base matrix, enhancing the ductility (6.3%). According to the findings, the AZ91/2 wt% carbon fiber/5 wt% SiC shows a grain reduction of 26 µm, a significant improvement in tensile strength of 319 MPa, better enhancement in hardness, and impact toughness of 95 HV0.1, 87 kJ/m2 and provides a better wear and corrosion resistance, which meets the requirements of structural applications.