论文部分内容阅读
通过金相显微镜、电子探针、扫描电镜和能谱仪等设备分析了MgCO3对AM60B合金的细化效果与机理。结果表明:MgCO3能够明显起到晶粒细化的作用,改善了实验合金的显微组织。一方面这是由于MgCO3加入合金后释放出了CO2,其中的C与Al元素反应生成了Al4C3,为合金提供了大量异质形核,从而使合金显著细化;另一方面是由于被排斥到液固界面前沿的C与Al化合物结晶时产生了富集,从而阻止了镁与铝的扩散。
The refining effect and mechanism of MgCO3 on AM60B alloy were analyzed by metallographic microscope, electron probe, SEM and EDS. The results show that: MgCO3 can obviously play the role of grain refinement and improve the microstructure of the experimental alloy. On the one hand, this is due to the release of CO2 after the addition of MgCO3 into the alloy, in which C reacts with Al to form Al4C3, providing a large amount of heterogeneous nucleation for the alloy, thereby remarkably refining the alloy; on the other hand, The C and Al compounds at the front of the liquid-solid interface are enriched during crystallization, preventing the diffusion of magnesium and aluminum.