Mg合金スラブ品質に及ぼす鋳造条件とCa添加の影響

抄録

Products made with magnesium alloy rolled sheets, such as cases of personal computers and so on, are recently increased by the advantage of the light weight. On the other hand, Ca addition into magnesium is also focused by a lot of researchers from the metallurgical point of view. The purpose of this study is to make clear the effect of casting conditions and Ca addition on the slab qualities of magnesium alloy. The results are follows. 1. By using of water cooled mold, the cooling rate at the center of the slab is about 5 times higher than that with non-water cooled mold. The high cooling rate reduces β phases (Mg₁₇Al₁₂), refines the grain size and enhances the hot workability. 2. The using of immersion nozzle and moving mold reduce the splash of the molten metal and improve the slab surface qualities. 3. Low casting rate reduces the porosity defects inside slabs. 4. Ca addition to magnesium alloy creates Al-Ca inter-metallic precipitates in place of β phases. Moreover, it makes the hot workability worse remarkably.