半个世纪来,钠(或钠块)一直是共晶铝硅合金用得最普遍的变质剂.但是,钠变质存在容易失效(仅30~45分钟)、不能重熔、吸气严重、浸蚀坩埚等一些缺点.所以,近十年国内外都在寻找新变质剂.锶(Sr)、锑(Sb)、钙(Ca)、碲(Te)、 铋(Bi)、铈(Ce)、镧(La)及混合稀土都有不同的变质能,其中,又以锶的变质特性最好.与钠相比,锶变质有长效作用,也能重熔.不过,锶来源困难、价格昂贵,不利推广使用. For half a century, sodium (or sodium) has been the most commonly used modifier for eutectic Al-Si alloys. However, sodium deteriorates readily (only 30-45 minutes), can not be remelted, and has a severe inspiratory, Etc .. Therefore, nearly 10 years are looking for new modifiers at home and abroad.Stride, Sb, Ca, Te, Bi, Ce, Lanthanum (La) and mischmetal have different metamorphic energies, among which strontium has the best metamorphism characteristic. Compared with sodium, strontium metamorphism has a long-term effect and can also be remelted. However, the source of strontium is difficult and expensive , Unfavorable promotion use.