R. Edwin Raj

Aluminum Melt Foam Processing for Light-Weight Structures

Aluminum foam was prepared by two routes, namely, gas injection technique and by the decomposition of TiH2 blowing agent. The foam structure can be largely controlled by the amount of degassing agent and duration of foaming. The heterogeneity in cell structure could be explained on the basis of foam stability, drainage in the cell walls, and heat transfer during quenching. The variation in cell size and drainage is negligible when the holding time is around 120 s at 750°C. The constant strain rate compression tests indicate that the Youngs modulus, plateau stress, and energy absorption capacity increases with relative density of the foam, while the densification strain reduces with increase in relative density.

Optimization of short Indian Areca fruit husk fiber (Areca catechu L.)–reinforced polymer composites for maximizing mechanical properties

ABSTRACT Natural fibers are being used as reinforcing materials for polymer composites due to their eco-friendly properties. Areca fruit husk fiber (AFHF) is one such fiber; it is currently discarded waste from the tobacco industry, but has huge potential. It is light in weight with a perforated surface that enables good bonding with a polymer matrix. In this study, comprehensive characterization of physical, chemical, thermal, mechanical, and microstructural properties was carried out on the fiber and the composite made with that fiber to optimize the fiber content. The optimum fiber content is found to be 40 wt.%, whereas beyond that, fiber pull-out and debonding reduces the load-bearing capacity of the composite. The specific properties of AFHF polymer composite are even higher than that of the popular E-glass fiber composite, which positions AFHF composite as an alternative structural material.

Cellulose powder treatment on Cissus quadrangularis stem fiber-reinforcement in unsaturated polyester matrix composites

Natural fibers from bio-renewable sources have the potential to be used as an alternate reinforcement for the perilous synthetic fibers. The hazards of prolong exposure to such fibers are quite serious, which demands scientific intervention. Natural fibers, like the one investigated – Cissus quadrangularis stem fiber (CQSF), have proven thermomechanical properties for polymer composite reinforcement. Enhancing fiber–matrix bonding through chemical treatments such as mercerization and deposition of cotton linters-based microcrystalline cellulose powder on fiber surface are comprehensively investigated. The mechanical properties of treated fiber composites reveal good bonding features through scanning electron microscopy analysis, which are further substantiated by the evaluation of mechanical property. In particular, 5 wt.% cellulose powder-treated CQSF/polyester composites showed distinguishable enrichment in mechanical and water absorption characteristics.