
Effect of multi-pass friction stir processing on thermal distribution and mechanical properties of AZ91
Author(s) -
Hoda Agha Amini Fashami,
Nasrollah Bani Mostafa Arab,
M. Hoseinpour Gollo,
B. Nami
Publication year - 2020
Publication title -
mechanics and industry
Language(s) - English
Resource type - Journals
eISSN - 2257-7777
pISSN - 2257-7750
DOI - 10.1051/meca/2020042
Subject(s) - friction stir processing , materials science , ultimate tensile strength , microstructure , indentation hardness , creep , composite material , alloy , scanning electron microscope , metallurgy
In this paper, the effect of multi-pass friction stir processing on mechanical properties of AZ91 alloy has been studied. For this purpose, the microhardness, tensile, and creep tests were conducted at several temperatures. Optical microscopy and scanning electron micrograph were used to study the microstructure of the processed samples. The experimental results indicated that at room temperature, the microhardness, tensile, and creep strength of the processed samples as compared to the unprocessed ones increased by 23%, 29%, and 38%, respectively. Also, after friction stir processing, the tensile and creep strength of the samples at 210 °C increased by 31% and 47%. In addition, a three-dimensional model was developed to simulate two-pass friction stir processing using ABAQUS/Explicit software. This model involved the Johnson-Cook models for defining material behavior during the process and identifying the fracture criterion. To control the mesh distortion during consecutive passes, the Arbitrary Lagrangian-Eulerian technique was used. Using the developed model, the peak temperature, thermal distribution, and residual stress field during multi-pass friction stir processing on AZ91 have been studied. The empirical results indicated the beneficial influence of the multi-pass friction stir processing on the microstructure and high-temperature mechanical properties of AZ91 alloy.