Experimental and simulation analyses of superplastic forming of A16063/SiCp composites

Abstract

Superplasticity is the ability of a material to exhibit very long neck free elongation prior to its failure. If the percentage of elongation is more than 200% then the material has superplastic forming capability and if the percentage of elongation is less than 200% then it is referred as extended plasticity. The material having high strain rate sensitivity index has more elongation. The advantage of superplastic forming is that, near net shape components can be produced which reduces the cost and weight. Superplastic forming has applications in the field of aerospace, automobile, architecture industries and medical applications. In recent days the superplastic forming was done in aluminium metal matrix composites. Aluminum based particulate Metal Matrix Composites have combined properties of metallic and ceramic. The properties of Aluminium Metal Matrix composites are high specific strength and stiffness, low thermal expansion coefficient, improved tribological properties and better high temperature strength. The composites were prepared by stir casting process. Aluminium 6063 alloy, as matrix was used for production of Metal Matrix Composites and SiC particles as reinforcement. Composites were prepared with 5%, 8% and 10% volumetric percentages of SiC particles. To refine the grains, thermomechanical treatment was performed in the cast components. Thermomechanical treatment has Solutionizing, warm rolling and natural ageing processes. The cast composites were solution treated at a temperature of 520 C and water quenched. Quenched composites were warm rolled at a temperature of 400 C. The thickness was reduced from 5 mm to 2.5 mm. The components were naturally aged for three days. Equiaxed grains were formed through thermomechanical treatment and it improved the superplastic forming. After thermomechanical treatment, the SiC particles were distributed uniformly throughout the matrix material. The properties of the composites were tested by Tensile test and Hardness test.