TITLE:
Study of Microstructure and Mechanical Behavior of Aluminum/Garnet/Carbon Hybrid Metal Matrix Composites (HMMCs) Fabricated by Chill Casting Method
AUTHORS:
M. G. Anantha Prasad, Nityanand Bandekar
KEYWORDS:
Aluminum, Chill Casting, Garnet, Hardness, Microstructure, Stir Casting
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.3,
March
12,
2015
ABSTRACT: HMMCs are significantly influenced by the reinforcements. Composites with two or more reinforcements
and finer grain structures are extensively used due to improved mechanical and tribological
properties. The evolution of finer and uniform microstructures is strongly dependent on
the cooling rate during solidification. In this investigation stir cast hybrid composites of aluminum
alloy LM13 was fabricated with garnet and carbon particulate reinforcements. Chills of various
materials such as copper, steel, iron and silicon carbide was used to accelerate the solidification.
Combination of dispersoid varies from 3 wt% to 12 wt% in steps of 3 wt% garnet and 3 wt% carbon
particulates. Microstructure characterization and mechanical properties such as hardness
and ultimate tensile strength of reinforced hybrid composites were examined. The test specimens
are prepared and tested as per American society for testing and materials (ASTM) standard. Vickers
hardness measurement was carried out to study the hardness of the composite. The effect of
chill and reinforcement characteristics was presented and compared with the hybrid composite
without chill material. The results confirm the positive relationship between mechanical behavior
and the dispersiod content. The copper chill cast composite with 9 wt% garnet and 3 wt% carbon
was found to increase mechanical properties.