Aging Behavior of YAl2p/Mg-14Li-1Al Composite

摘要:

采用搅拌铸造的方法制备了YAl2p/Mg-14Li-1Al复合材料，并使用硬度试验、差热分析和X射线衍射等方法对该材料的时效行为进行了研究。结果表明，基体合金及其复合材料硬度的变化均与θ-MgLi2Al相的析出和分解有关。复合材料的强化效果来自于YAl2颗粒的加入以及基体合金的析出行为。其中，加入YAl2颗粒所产生的强化效果是稳定的，而基体合金的析出强化则是不稳定的且依赖于它自身的时效行为。此外，YAl2颗粒的加入延缓了时效行为的发生。

Abstract:

YAl2p/Mg-14Li-1Al composite was made by a stir-casting technique. The aging behavior of the composite was investigated using hardness test, differential scanning calorimetry, and X-ray diffraction. The results show that the microhardness variations of both the matrix alloy and its composite are related to the precipitation and decomposition of θ-MgLi2Al phase. The strengthening of the composite is from the addition of YAl2 particulates and the precipitation in matrix alloy. The former contribution is stable, but the latter is unstable and depends on the aging behavior. The addition of YAl2 particulates delays occurring of the aging behavior of composite.