Al-Al_4C_3-TiC中间合金对Mg-Al系合金的晶粒细化

Grain refinement of Mg-Al based alloys by a new Al-Al4C3-TiC master alloy

通过熔体原位反应法制备了一种Al-Al4C3-TiC中间合金。在该中间合金中,Al4C3颗粒被TiC颗粒包围,Al4C3颗粒和TiC颗粒尺寸分别在2.5~8.0μm和0.5~1.5μm之间。试验表明,该中间合金对AZ31有良好的细化作用。当加入1%的中间合金时,AZ31的晶粒尺寸由原来的1050μm减小到260μm。Al4C3颗粒或者Al4C3颗粒团簇充当了α-Mg的异质形核核心,这导致了明显的晶粒细化。

A type of Al-Al4C3-TiC master alloy was fabricated by melt in-situ reaction. In the master alloy, Al4C3 particles with a size of 2.5-8 μm were surrounded by TiC particles with a size of 0.5-1.5μm. Grain refinement experiments reveal that the master alloy can refine AZ31 efficiently. After addition of 1wt.% Al-Al4C3-TiC master alloy, the grain size of AZ31 was decreased from 1 050 μm to 260μm. Al4C3 particles or Al4C3 particle clusters act as the nucleation sites leading to the evident grain refinement.