Mechanical Property Evaluation of Heat Treated Insitu Al- TiB2 Composite after Severe Plastic Deformation

Abstract

Nano composites have been attracted the materials community since last decade and a lot of emerging technologies have been developed to refine the grain size to nano and submicron level. Metal matrix composites are promising materials for number of applications in the field of aerospace, defence and automobile industries for their good strength and better structural properties. Further aluminum metal matrix composites have been widely used for their light weight and possessing sufficient mechanical properties which can be tailored to the demands of different industrial applications by suitable combinations of matrix, reinforcement and processing route. In recent years sufficient amount of work has been carried out on composite subjected to severe plastic deformation techniques to down size the grain size to submicron level. Amongst various techniques under severe plastic deformation, Equal channel angular pressing is one such promising technique which is employed on composite materials to obtain the expected outcomes viz. ultrafine grains and better mechanical properties. Enormous amount of plastic strains are incorporated in the bulk material to refine the grain size and enhance the strength of the composite. Conventionally processed metals have the grain size between 10-100 micrometers. Severe plastic deformation techniques helps in reducing this to 1 micrometer or even less which enhances the yield strength to more than 100%. This paper highlights the effect of ECAP and its influence on mechanical property of a heat treated insitu aluminum titanium boride composite. The heat treated composite subjected to SPD through ECAP exhibited a better mechanical property than the composite subjected to SPD without heat treatment. The Microstructural analysis revealed that the grain structure of heat treated composite obtained fine grains compared to composite without heat treatment. According to hall Petch equation the grain refinement would be the reason behind enhanced strength in heat treated composite subjected to ECAP.