Modares Mechanical Engineering

Modares Mechanical Engineering

Tool's Speed effect on hardness and residual stress in friction stir welded Al 2024-T351: Experimental method and Numerical simulation

Authors
Danial Ghahremani Moghadam
Khalil Farhang Doost
Ali Rastegar Mohammadabadi
Mohammad Ramezani Moghadam
Abstract
In this study, microstructure, microhardness and residual stress in the butt jointed friction stir welded aluminum alloy 2024-T351 plates with different tool’s rotational and traverse speed is studied. According to the 2024-T351 aluminum is a heat treatable alloy, Hardness test results showed that increasing rotational speed or decreasing traverse speed of the tool reduced hardness in the weld zone. Then, using standard X-ray diffraction, which is a non-destructive method, residual stress in the welded samples is determined. A thermal model of friction stir welding process is simulated by using finite element method in the ABAQUS software. Comparison of residual stress results that obtained from the numerical solution with experimental measurements show that, the numerical model can predict the residual stress fields in friction stir welding joints reasonably. The results show that, increasing rotational speed, cause to higher residual stress in the weld zone, due to generation the higher thermal gradient and also, The higher tool traverse speed will induce a greater high-stress zone with a higher stress value in the weld, because of, a lower heat input and result in the relatively harder metal in the weld zone, causes a greater resistance to the plastic extrusion.
Keywords
Friction Stir Welding
Residual Stress
X-ray diffraction
finite element method
Aluminum Alloy 2024-T351
Modares Mechanical Engineering
Volume 15, Issue 2
April 2015
Pages 61-71