Abstract
Several challenges stand in the way of the production of metal matrix composites (MMCs) such as higher processing temperatures, particulate mixing, particulate–matrix interface bonding issues, and the ability to process into desired geometrical shapes. Although there are many studies showing composites with single particulate reinforcements, studies on composites with multiple reinforcing agents (hybrid composites) are found to be limited. Development of a hybrid particulate composite with optimized mechanical and tribological properties is very significant to suit modern engineering applications. In this study, Al–Si hypereutectic alloy (A390) was used as the matrix and silicon carbide (SiC), graphite (Gr), and molybdenum di-sulphide (MoS2) were used as particulates. Particulate volume (wt %) was varied and sample test castings were made using a squeeze casting process through a stir casting processing route. The evaluation of the mechanical testing indicates that the presence of both the hard phase (SiC) and the soft phase had distinct effect on the properties of the hybrid aluminum matrix composites (HAMCs). Composite samples were characterized to understand the performance and to meet the tribological applications. The 3D profilometry of the fractured surfaces revealed poor ductility and scanning electron microscopy fractography study indicated an intra-granular brittle fracture for HAMCs. Also, the dry sliding wear tests indicated that the newly developed HAMCs had better tribological performance compared to that of A390 alloy.
Highlights
Aluminum matrix composites (AMCs) have received great attention in the market of modern engineering materials which mainly focus on cost, quality and durability, styling and performance, emission and fuel economy, and recyclability [1]
Considering A390 alloy as a “quasi-binary alloy”, it belongs to a hyper-eutectic group of Al–Si alloy systems
There were a few defects, such as cold shut, due to decreased fluidity of melt added with silicon carbide (SiC) particles and raining due to improper melt pouring
Summary
Aluminum matrix composites (AMCs) have received great attention in the market of modern engineering materials which mainly focus on cost, quality and durability, styling and performance, emission and fuel economy, and recyclability [1]. A literature review indicates the dominance of particulate reinforced AMCs due to their ease of manufacturing and process competitiveness This type of composite is produced by (i) solid-state processing such as powder metallurgy techniques, physical vapor deposition, diffusion bonding, etc. Monolithic materials are either incapable of satisfying the desired design requirements or are too expensive to meet superior tribological performance whereas HAMCs may be designed to meet this desired performance This investigation is focused on the study of composites using A390 aluminum cast alloy, as this alloy has wide acceptance in tribological applications such as cylinder blocks, transmission pump and air compressor housings, small engine crankcases, and air conditioner pistons [19]. The experimental observations in the production and characterization of HAMCs is expected to serve as a qualitative and quantitative guide to understand the effect of particulates in rendering various properties
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
