Summary: | In the present work, the in-situ TiB<sub>2</sub>/Al12Si4Cu2NiMg (denoted as ‘Al-12Si’) composites were successful synthesized through the salt-metal reaction route. The influences of weight fraction (0, 4, and 9 wt.%) and heat treatment (T5 and T7) on the tensile creep deformation were studied at ≥623 K under constant load in air. At the investigated temperature and stress condition, TiB<sub>2</sub> particles increased creep deformation resistance, as compared to the unreinforced alloy, while the composites presented similar strength when the weight fraction of reinforcement increased from 4% to 9%. It was found that the steady-state creep rate was lower in the 4 wt.% TiB<sub>2</sub>/Al-12Si composite (T5), as compared with that in the 4 wt.% TiB<sub>2</sub>/Al-12Si composite (T7). The result has been rationalized by using the load-partitioning model and relative to the evolution of the rigid phase. The creep deformation of the 4 wt.% TiB<sub>2</sub>/Al-12Si composite was controlled by the climb of dislocations in the aluminum alloy matrix.
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