Effect of ball-milled MgO and Si3N4 addition on the physical, mechanical and thermal behaviour of aluminium based composite developed by hybrid casting technique

Abstract

ABSTRACTComposite material via hybrid casting techniques. Ball-milling of Si3N4 and MgO powder was carried out for 100 hours to obtain in single entity particles. MgO powder is used to enhance wettability property of composite with Si3N4 reinforcement in AA2024 aluminium alloy. However, MgO was also responsible to improve tensile strength and hardness of composite material. Microstructure results showed the fair distribution of reinforcement particles developed by the hybrid casting technique. Maximum tensile strength and hardness were found to be 219.55 MPa and 80.86 BHN for ball-milled AA2024/7.5 % Si3N4/5% MgO composite material as heat treated. Minimum thermal expansion was also found for composition AA2024/7.5% Si3N4/5% MgO composite. However, minimum corrosion loss was observed for composition AA2024/10% Si3N4/2.5% MgO composite material. Though, toughness and ductility were reduced by adding the Si3N4 and MgO particles in AA2024 aluminium alloy. XRD result showed the presence of SiO2, Mg, Al, Si3N4, Cu and MgO in ball-milled AA2024/7.5% Si3N4/5% MgO composite material.