Development and machining of Aluminium Hybrid Metal Matrix Composite

Abstract

Different industries have explicit applications of Aluminum Metal Matrix Composites (AMMCs). However, porosity, wettability and Ultimate Tensile Strength (UTS) are important factors that need to consider while fabricating AMMCs. This study focuses on identification of most significant parameters for stir casting process, optimization of machining parameters for surface roughness, study of cutting tools and chips during machining process and corrosion study of newly developed composite material. Significant as well as non-significant factors have been identified from the literature survey and trial experiments. Without considering the significance of given responses, identified factors have been represented graphically by the c. FMEA (Failure Mode and Effect Analysis) was used to find out significant parameters from all the parameters that represented by fishbone diagram. Afterwards, Plackett-Burman design was used to screen the most significant parameters out of the significant parameters. Stirring speed, stirring time, preheating temperature and reinforcement amount was found the most significant parameters to attain high UTS and low porosity. However, because of the unfavourable combination of parameters % porosity increased beyond 7% during screening design based experiments. Subsequently, these parameters have been optimized by factorial design. The result shows optimized parameters stirring speed 650 rpm and stirring time 12 minutes that provides low porosity and high UTS. UTS improved up to 310 MPa due to an optimized range of stirring speeds and stirring time. However, porosity increased beyond 3% due to excess stirring in cast composites during factorial design based experiments. Moreover, studies have been carried out to understand the effect of stirring, fluxing, degassing and moulding methods on porosity, UTS, clustering and surface finish of the cast composite. It was observed from a supplementary study that permanent mould reduces surface roughness below 3and#956;m, compared to t