FRICTION STIR PROCESSING OF ALUMINUM ALLOY AND EFFECT OF NUMBER OF PASSES

Abstract

Friction stir processing is a newly developed solid state processing technique in which a rotating tool is inserted in a work piece for localized micro-structural modification for specific property enhancement. Alloys like aluminium, magnesium, copper etc. are most suitable for friction stir processing. Friction stir processing increases the super plasticity of material. It modifies the microstructure, increases micro-hardness and tribological properties like tensile strength, wear behavior etc. are improved. The aluminium alloy (grade 1050 have major alloying elements as iron and silicon. In this study we obtain optimum traverse and rotational speeds are 25 m/min and 1600rpm after a number of trails. The square pin profiled tool produced defect free FSP region compare to other pin profiles and obtain defect free micro and macrostructure in friction stir processing region at D/d ratio 3. These are fixed based on the literature review. In this study we processed the aluminium alloy (AA1050) with square pin profile of H-13 tool material at 1600rpm rotational speed and 25mm/min traverse speed by friction stir processing. Final results shows 9 percent increase in tensile strength compare to base alloy and hardness of processed sample increase compare to base material sample and tensile elongation decrease as number of passes increase. Wear loss of processed specimen also reduced due to increase in hardness of processed sample.