The High-Temperature Creep Behavior of In-Situ TiB2 Particulate Reinforced Al12Si4Cu2NiMg Composite

Abstract

In the present work, the in-situ TiB2/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, TiB2 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.% TiB2/Al-12Si composite (T5), as compared with that in the 4 wt.% TiB2/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.% TiB2/Al-12Si composite was controlled by the climb of dislocations in the aluminum alloy matrix.