Effect of Ce addition on microstructure of Mg-9Li alloy
(1. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China;
2. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
3. School of Mechanical and Mining Engineering, University of Queensland, St Lucia 4072, Australia)
2. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
3. School of Mechanical and Mining Engineering, University of Queensland, St Lucia 4072, Australia)
Abstract: The as-cast and as-extruded Mg-9Li, Mg-9Li-0.3Ce alloys were respectively prepared through a simple alloying process and hot extrusion. The microstructures of these alloys were investigated by optical microscope (OM), scanning electron microscope (SEM), X-ray diffractometer (XRD) and energy dispersive spectrometer (EDS). The results indicate that Ce addition produces a strong grain refining effect in Mg-9Li alloy. The grain size of the as-extruded alloy reduces abruptly from 88.2 μm to 10.5 μm when the addition of Ce is 0.36%. Mg12Ce is verified and exists inside the grains or at the grain boundaries, thus possibly pins up grain boundaries and restrains the grain growth.
Key words: magnesium-lithium alloys; microstructure; grain refinement; intermetallic compound