Study on the Refining Behavior of Al-Si Alloys Doped with Al-Ti-C Intermediate Alloys at Different B Doping Temperatures

In this paper, a novel Al-5Ti-0.3C-0.2B intermediate alloy with an efficient refining effect on Al-Si alloys by a low-cost and high-performance fabrication process is developed. The results show that the addition of only 0.15 wt.% of Al-5Ti-0.3C-0.2B intermediate alloy is able to refine the average grain size of Al-Si alloys to 120 ± 5 μm, which is 28.7% higher than the reference value of 0.2 wt.% addition. Additionally, TiAl3 in bulk form has a faster response and more stable refinement than TiAl3 in needle form. The blocky TiAl3 generated at low temperature will turn acicular or elongated as the temperature increases, slowing the response speed and increasing the time required to achieve the ideal refinement effect. We are convinced that this work will provide a reference for developing new aluminum alloy refinement intermediate alloys.