High-temperature tensile properties of friction stir processed AA2024 aluminum alloy under varying in situ cooling conditions

Abstract

The study investigates the impact of in-situ cooling conditions and friction stir processing (FSP) on the high-temperature tensile properties of AA2024 alloy under various cooling conditions and regulated parameters. The tensile tests were done at strain rates of 0.0003–0.03 s⁻¹ and temperatures ranging from room temperature to 400 °C. The study found that the FSP procedure and cooling environment significantly affect the mechanical characteristics of samples at high temperatures. Under all cooling conditions, yield and ultimate strength generally decreased with increasing deformation temperature. It was found that at 325 °C with air cooling at a strain rate of 3 × 10⁻² s⁻¹, the highest yield and ultimate strengths were achieved (280 MPa and 354.9 MPa, respectively). Additionally, compared to the base sample, the FSP-treated samples showed an increase in elongation at 325 and 400 °C temperatures. In FSP samples, increasing the strain rate also increased the yield strength and ultimate strength. Also, in all three strain rates in all three cooling conditions, the total elongation has increased compared to the base metal. Overall, the results of this research demonstrate that it is feasible to give aluminum alloy 2024 the required mechanical qualities at high temperatures by selecting the right FSP and cooling process parameters.