低温反应自熔法原位合成MgO颗粒增强镁基复合材料

In-Situ Fabricated MgO Particulate Reinforced Magnesium Matrix Composite by Low Temperature Reaction Melting

摘要:

采用低温反应自熔新工艺，由经过预氧化的Mg粉原位合成了MgO颗粒增强镁基复合材料，并对其显微组织和力学性能进行了检测。结果表明：低温反应自熔时，因Mg颗粒处于全熔或半熔状态，表面的氧化膜得到了有效地破碎、细化，并在液相熔蚀和自身表面张力的共同作用下，球化成微米和亚微米级MgO颗粒；形成的MgO颗粒不但与基体结合良好、分散均匀，而且因具有很高的强度和刚度，对基体产生了较好的增强效果。与粉末冶金法相比，采用低温反应自熔法制备的镁基复合材料的组织和性能均显示出明显优势。

Abstract:

Adopting a novel synthesizing method-low temperature reaction melting (LRM), a MgO particulate reinforced magnesium matrix composite was in-situ fabricated using pre-oxidized Mg powders. The microstructures and mechanical properties of the composite were investigated by microstructure observation and tensile tests. The results showed that, due to the melting of Mg powders during LRM treatment, the oxide film on the surface of Mg powder was effectively broken into pieces, refined and subsequently, spheroidized into particulates with micron or sub-micron sizes by the joint effect of the liquid phase Mg and the surface tension of MgO itself. Moreover, The formed MgO particulates possess not only good interfacial bonding with the matrix and uniform distribution, but also high strength and stiffness, which is beneficial to improving the reinforcement effect to the matrix. As a result, the LRM method can bring better microstructures and mechanical properties to the composite compared to powder metallurgy process.