稀土对AZ91镁合金阻燃性和机械性能的影响

Effects of RE on Ignition-Proof and Mechanical Properties of AZ91 Magnesium Alloy

针对应用最广的镁铝锌锰系镁合金AZ91,探讨了La的加入对其阻燃性和机械性能的影响。在自制覆盖剂保护下,按照AZ91镁合金化学计量比备料,熔铸了3种不同稀土含量(0,0.2%,0.4%)的样品。对样品进行燃点、硬度测定和金相观察。结果表明,富La稀土不仅可有效地提高镁合金的燃点(在AZ91系镁合金中添加0.4%的富镧稀土可使燃点提高15℃),还可细化晶粒,显著提高了镁合金的硬度,合金的布氏硬度由不含稀土时的548.8MPa提高到656.6MPa。

Taking AZ91 alloy which is widely used into account, the effects of adding RE rich in La on the ignition-proof and mechanical properties of the alloy were investigated. In the coverage of home-made protection course, three kinds of sample with RE content of 0, 0.2% and 0.4% were prepared in accordance with the composition ratio of magnesium alloy AZ91, whose Ignition and hardness was determined and the microstructure observed by metalloscope. The results show that the La-rich rare-earth could not only effectively raise the ignition point of magnesium alloy, but also refine grains and significantly increase the hardness of magnesium alloy, which in content of 0.4% can rise the ignition by 15c, and the hardness from 548.8 MPa to 656.6 MPa.