Characterization and evaluation of microstructure and mechanical properties of ZrO₂ reinforced Al6061 metal matrix composite using stir casting process

ABSTRACT

The stir casting technique has proved to be a well-known method for processing Metal Matrix Composites (MMCs) owing to the fact that it is an easy and cost-effective process. The current work explores themicrostructure characteristic and mechanical property of Zirconium dioxide (ZrO₂) particle reinforced with Aluminium 6061 (Al6061) matrix fabricated through the stir casting method. Casting is carried out with ZrO₂ as reinforcement phase for 2, 4, 6, 8 and 10 wt%. Specimens for different testing were prepared through machining in confirmation with ASTM standards for composites. In this study, SEM morphology is used to analyse the reinforcement distribution in a metal matrix, and it demonstrates that there is a uniform distribution of hardened particles in the metal matrix, with no cluster formation, resulting in increased strength. Tensile and hardness studies reveal that Brinell Hardness Number (BHN) and Ultimate Tensile Strength (UTS) increase with an increase in the percentage of reinforcement and maximum UTS is observed to be 223 MPa for 6% of reinforcement. Further increase in wt% of percentage of reinforcement tends to decrease the UTS and hardness property of MMCs. Overall, with the addition of reinforcement MMCs have shown 49% increase in tensile strength and 15–20% increase in hardness.

KEYWORDS:

• Metal matrix composite
• Al 6061
• Zirconium dioxide
• stir casting
• ultimate tensile strength

Disclosure statement

No potential conflict of interest was reported by the author(s).