Numerical Investigation of Tool Stirring Speed in Friction Stir Processing of AA7075 Using Smoothed-Particle Hydrodynamics

Abstract

Friction Stir Process (FSP) is considered one of the most convenient, effective, and environmental friendly manufacturing processes. In these processes, a tool involves a pin that blends the material around it and a shoulder that creates frictional heat. On the other hand, the pin mixes the soft material to refine the grain structure. This paper aims to investigate a thermal model using Altair to numerically simulate the temperature distribution profiles of 7075 Aluminum Alloy material using FSP. Using a novel technique called Smoothed-Particle Hydrodynamics (SPH), we extracted the temperature distribution in the Stir Zone (SZ) for 900 RPM, 1200 RPM, and 1500 RPM Tool Rotational Speed (TRS) with constant Tool Traverse Speed (TTS). The temperature results obtained are incremental with increasing TRS. As a result, the temperature achieved from 900 RPM to 1500 RPM has increased by 21.20%. In addition, the obtained temperature is almost 50% of the melting point. The material flow on both Advancing Side (AS) and Retreating Side (RS) shows the thorough material mixing. The SPH technique helps to investigate the proper material flow modeling by dividing the AS and RS nodes and it was observed that they have thoroughly been mixed near the FSP tool pin.