Effect of Cooling Rate on the Mechanical Properties of Ceramic Reinforced Aluminium Based Metal Matrix Composite for Marine and Offshore Engineering Applications

Abstract

This paper examines how the cooling rate influences the microstructural and mechanical characteristics of hybrid metal matrix composite made of Al 7075 reinforced with silicon carbide (SiC) and boron carbide (B4C) in regard to marine and offshore applications. The composite was created by stir casting and allowed to solidify under four conditions of moulds to have varying cooling rates. A K-type thermocouple was used to record the thermal histories and specimens were assessed by tensile, hardness, impact and microstructural analysis. Findings indicate that faster cooling rates yield finer grain structures and better distribution of reinforcement resulting in higher yield strength, hardness and impact energy, and slower cooling rates yield better ductility. Tensile behaviour was analysed using finite element analysis that was found to be in good agreement with the experimental findings with an error of less than 5%. The research proves that the use of controlled cooling can be effective to customise composite properties towards lightweight marine structures under dynamic loading.