A Study on the Effect of Co Addition on the Microstructure and Mechanical properties of A356 Alloy Cast in Permanent Mould

Abstract

Aluminium alloys have found application in many areas like automobile, aerospace and in fighter jets. The main problem for these alloys are the lack of mechanical properties and wear properties. These mechanical properties have huge effect from the microstructure. For analyzing the performance of the aluminium alloys, a study is carried out to examine the effect of cobalt addition on the hypoeutectic aluminium alloy microstructure. Pure cobalt of varying weight % were added into a clay- graphite crucible containing Al ingot. The melting was conducted by using an electric arc furnace at a temperature of 850°C±20°C and were poured into a permanent mould to obtain cast specimens. Solutionisation and aging were performed at a temperature of 525°C for 12hrs and 155°C for 1, 2,3,4,5 hrs.. The hardness of the developed alloy was found to increase with an increase in the Co addition. The UTS and YS was found to be increased with an increase in the addition of cobalt and the ductility was found to reduce with increase in the cobalt percentage.