Microstructural characteristics of spray formed zircon sand reinforced LM13 composite

Aluminum metal matrix composites (MMC) are one of the attractive light weight substance which find their application in automotive and aerospace industries. In the present work spray forming technique has been used to prepare zircon sand reinforced LM13 alloy. The spray formed composite and base alloy were characterized using optical and scanning electron microscopes. The thermal analysis of the base alloy, zircon sand particles and reinforced composite has been done with differential thermal analyzer and dilatometer to see its applicability at high temperature. The microstructural features and hardness of spray formed LM13/zircon sand composite revealed equiaxed morphology with nearly uniform distribution of zircon sand particles in the middle of preform as well as good particle/matrix interfacial bonding. The linear expansion coefficient of base alloy is found to be 8.67 x 10-6 K-1 and for spray formed composite is 8.38 x 10-6 K-1 (5% Vf of zircon sand) and 9.11 x 10-6 K-1 (15% Vf of zircon sand) in 25-465 oC temperature limit, which is quite comparable indicating good interfacial bonding.