Fabrication and Microstructure Evolution of Al/Mg Bimetal Using a Near Net Forming Process

ABSTRACTThe Al/Mg bimetal was fabricated by using the lost foam casting method that is considered a near-net forming process, and the microstructure evolution of the Al/Mg bimetal from different cross section locations of the bimetal was investigated in the present work. An obvious interface layer generated in the middle of the aluminum and magnesium, which showed a variation for different cross section locations of the bimetal. The interface layer at the bottom cross section location had a maximum thickness, wherein a big gap was observed. The thicknesses of the interface layer gradually decreased from the bottom location to the top location. At the middle cross section location, the interface layer was uniform and compact. In contrast, the non-uniform interface layer was obtained at the top cross section location, and the partial location had no the interface layer. The interface layers at the bottom and middle locations consisted of three reaction layers including the Al12Mg17 + δ-Mg, the Al12Mg17 + Mg...