Multi Response Optimization of Friction Stir Process Parameters on AA2024 / SiC Composite Fabricated Using Friction Stir Processing

Abstract

Friction Stir processing is used to modify the mechanical properties of the metal by refining the grain structure, which is proven to be effective for selective surface modification and also retaining the properties of bulk. In this present work Aluminium Alloy 2024 is used as a matrix material, which possess poor corrosion resistance and the softness of the material leads to high wear rate. Silicon Carbide (SiC), which has high hardness, high corrosion resistance and withstands high temperature is used as the reinforcement material. The present work aims to enhance the mechanical properties by refining the grain structure, and improvement in the corrosion behavior of AA2024 through surface composite (AA2024/SiC) fabricated using FSP. The Aluminium Metal Matrix Composite is fabricated using Friction Stir Processing by varying the volume fraction of SiC, rotational speed and traverse speed. The process parameters used in this experiment are rotational speed of 1200 rpm, 1500 rpm & 1800 rpm, traverse speed of 44 mm/min, 60 mm/min & 72 mm/min and volume fractions 8%, 16% & 24% of SiC. The experiment is conducted using Taguchi’s L9 Orthogonal array considering three factors at three different levels. A square pin tool of H13 steel with hardness of 60 HRC is designed and fabricated to provide better material flow of the reinforcement particles. The Silicon Carbide (SiC) particulate reinforced Aluminium Metal Matrix Composite (MMC) has been successfully fabricated through single pass FSP. The tensile test were carried out using universal testing machine as per ASTM E8 standards to determine the elongation and the ultimate tensile strength (UTS) of FSPed AA2024/SiC composites and the corrosion rate were evaluated using immersion corrosion testing method by weighing the before and after weights of the samples as per ASTM G31-72, 2004. Grey Relational Analysis (GRA) is performed on the multiple response test results to find the optimum friction stir process parameters. Analysis of Variance (ANOVA) is performed to determine the most significant contributing friction stir process parameters at a 95% confidence level.