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采用第一滴气泡法和减压凝固法 ,研究稀土镧对铝硅合金 (Al+ 11.2 %Si)中氢的作用 ,结果表明 :添加一定量的稀土镧 ,铝合金液体中溶氢量显著减少 ,铸件的针孔缺陷明显改善 ;稀土的去氢机理 ,认为稀土除氢效果不形成镧化氢 ,而主要是稀土镧减少氢在铝合金液体中的活度 ,降低铝合金液体中氢的析出压力 ,在凝固过程中增加氢在铝固溶体中有效分配系数。从热力学角度分析在铝液中形成镧化氢的条件。
The effects of rare earth lanthanum on the hydrogen in Al-Si alloy (Al + 11.2% Si) were investigated by the first droplet bubble method and the decompression solidification method. The results showed that the amount of hydrogen dissolved in the rare earth lanthanum and aluminum alloy significantly decreased, The pinhole defects of the castings are obviously improved. The mechanism of dehydrogenation of rare earths is that the effect of rare earth dehydrogenation does not form lanthanum hydride, but mainly the rare earth lanthanum reduces the activity of hydrogen in the aluminum alloy liquid and reduces the pressure of hydrogen precipitation in the aluminum alloy liquid , Increasing the effective partition coefficient of hydrogen in aluminum solid solution during solidification. The thermodynamic analysis of the formation of lanthanum hydride in molten aluminum conditions.