6TH International Congress on Technology - Engineering - Kuala Lumpur3 - Malaysia (2018-07-19)

Microstructure, Mechanical And Damping Characteristics Of Extruded Al-bn Nanocomposites

Nano-boron nitride (BN) particulates (0, 0.5, 1.0 and 1.5 vol.%) reinforced Al metal matrix composites were fabricated by powder metallurgy (PM) process employing microwave sintering and hot extrusion techniques. The effect of boron nitride (BN) concentration on physical, structural, mechanical, thermal and damping properties of extruded nanocomposites was studied using various characterizing tools. Scanning electron microscopy analysis reveals the homogenous distribution of BN nanoparticles in the aluminum (Al) matrix. Mechanical testing indicates that the hardness, elastic modulus and tensile/compression strength increases with increasing amount of BN nanoparticles in the matrix. Particularly, a significant improvement in tensile strength (36%) for Al-1.5 vol.% BN nanocomposites is noticed when compared to the matrix. This improvement strength can be attributed to the dispersion hardening of the Al matrix due to the presence of hard BN nanoparticles. Thermal analysis shows that the coefficient of thermal expansion (CTE) decreases with increasing amount of BN which may be ascribed to inherent low CTE of BN nanoparticles used as reinforcement. The addition of BN nanoparticulates enhanced the damping characteristics of pure Al with Al-1.5vol.% BN nanocomposite exhibiting the maximum damping capacity and damping loss rate with a minimum change in elastic modulus. The improved combination of properties exhibited by Al-BN nanocomposites make them potential candidates for a wide spectrum of industries especially for weight critical applications.
Abdul Shakoor, Penchal Reddy Matli, Adel Mohamed, Manoj Gupta