稀土和锶变质的Al—Si—Mg合金

选择理想的变质剂是制备高强韧铸造Ａｌ－Ｓｉ－Ｍｇ合金的重要手段。采用富镧混合稀土和锶对Ａ３５７合金进行了变质处理，研究了它们对合金铸态、力学性能及含量的影响。结果表明，在保证合金含铁量Ｆｅ≤０．１１％时，富镧混合稀土比锶有更理想的除氢和变质效果细化组织中共晶硅的能力和综合力学性能。

Modification Effects of La-Rich Mischmetal and Strontium Metal on A357 Alloy

Opting for desirable modifiers is an important way to obtain coast Al-Si-Mg alloys with both high strength and good toughness properties.Structures,mechanical properties and hydroden contents of as-cast and as-heattreated A357 alloy are investigated by comparing modification effections of lanthanum(La)-rich mischmetal and Strontium (Sr).It is shown from our experiments that modification effections of La-rich mischmetal is better than that of Sr as Fe content in the alloy is lower than 0.11% in the aspects of removal of hydrogen from the alloy,refinement of entectic silicons and improvement of mechanical properties,therefore,La-rich mischmetal is a desirable modifier for Al-Si-Mg alloy.