Taguchi analysis of heat treatment variables on the mechanical behavior of alumina/aluminum metal matrix composites

Alumina-reinforced aluminum 6061 alloy composites containing 10, 15 and 20 volume percentage particulates were tested using the standard tensile and Charpy impact toughness tests. A statistical approach, known as the Taguchi method, was implemented to identify heat treatment conditions for improved tensile and impact toughness properties. Modulus of elasticity, yield strength, and ultimate tensile strength all increased while impact toughness decreased as a function of the volume percentage of reinforcement for the alumina/aluminum composites in the T6 heat treated condition. Taguchi analysis results indicate that, on average, a 4% increase in yield strength and a 7% increase in ultimate tensile strength over the standard T6 heat treatment can be attained using a heat treatment of 6 h of solutionizing at 529°C and 12–18 h of aging at 160°C. Similarly, using a heat treatment of 2 h of solutionizing at 529°C and 12 h of aging at 127°C results in an impact toughness improvement of more than 87% over the standard T6 heat treatment.