Effect of two-stage aging process on mechanical properties of QAl9-4 aluminum bronze alloy

In this paper, the effects of the aging process on the microstructure and mechanical properties of QAl9-4 aluminum bronze alloy were investigated with orthogonal test. The results show that different process parameters have different effects on alloy properties, with the order of influence degree being second-order aging temperature > first-order aging temperature > first-order aging time > second-order aging time. The variance analysis of orthogonal test results showed that the optimal two-stage aging process was (150 ℃/2 h)+(500 ℃/2.5 h), and the alloy was treated by this process. Compared with the single-stage aging treatment, the compressive strength, ultimate compression ratio, and hardness of the alloy treated by the optimized two-stage aging process are increased by 14.79%, 25.59%, and 5.28%, respectively. Finally, the microstructure characterization was performed on alloys treated under different aging processes. The results reveal that the differences in properties are attributed to the alloys after two-stage aging treatment containing more dispersed enhanced phases and fewer γ₂ phases.Therefore, QAl9-4 aluminum bronze alloy can obtain better performance by two-stage aging treatment than that of single-stage aging treatment.