(上海交通大学 材料科学与工程学院，上海 200030)
摘 要: 研究了一种含有稀土化合物的铝合金新型熔剂JDN-I。结果表明，该熔剂通过发生一系列的物理和化学反应，不仅可使A356合金熔体720 ℃时的含氢量由大于0.30 mL/100 g(Al)下降到0.10 mL/100 g(Al)以下，除气效果显著，并使A356合金的室温抗拉强度提高7.27%，延伸率提高85.58%。该熔剂还具有细化晶粒和变质的作用，分析了该熔剂发生作用的机理，提出了有效稀土量和临界有效稀土量的概念。
关键字: 铝合金； 稀土熔剂； 除氢除杂； 有效稀土量； 临界有效稀土量
（College of Materials Science and Engineering，
Shanghai Jiaotong University， Shanghai 200030，P.R.China）
Abstract: A new flux—JDN-I including rare earth compounds for aluminium and its alloys was introduced. With complex physical and chemical effect， function of degassing， drossing， covering， refining and modification was excellent. The hydrogen content could be decreased greatly with JDN-I in A356 aluminium meltfrom >0.30 mL/100 g(Al) to <0.10 mL/100 g(Al),σb be increased by 7.27% and δ be increased by 85.5%. At the meantime， with JDN-I the mechanical properties of A356 could be increased. The mechanism of JDN-I improving properties and microstructure was discussed. The concepts of effective rare earth quantity and critically effective rare earth quantity were proposed also.
Key words: aluminum alloys; rare earth flux; degassing hydrogen and drossing; effective rare earth quantity; critically effective rare earth quantity
