High cooling rate solidification: Promoting uniform distribution of nano TiB2-TiC particles and enhancing the high-temperature mechanical properties of Al5Cu alloy

Through high cooling rate solidification technology promotes the uniform distribution of nano TiB₂-TiC particles, significantly enhancing the high-temperature tensile properties and creep resistance behaviors of Al5Cu alloy. This technique not only can uniformly refine the grains, but also can effectively realize the diffuse distribution of TiB₂-TiC particles. The uniformly dispersed nano TiB₂-TiC particles enhance the pinning effect on grain boundaries and dislocations, enabling cooperative deformation between grains and thus improving the high-temperature mechanical properties of the Al5Cu alloy. After T6 heat treatment, the results show that the high-temperature performance of the 0.1 wt% TiB₂-TiC/Al-5Cu alloy, prepared under high cooling rate solidification, is superior to that of the original Al5Cu alloy. Its ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) are improved by 5.6 %, 11.5 %, and 26.5 %, respectively, compared to the original Al5Cu alloy. Additionally, no creep fracture occurred within 24 h under conditions of 473 K and 200 MPa. The steady-state creep rate was 1.2 × 10⁻⁶ /s, which represents a 58.6 % reduction compared to the original AlCu alloy.