The Influence of the Additional Fe and Mn in Al Alloy on the Die Soldering Phenomenon

Die soldering layer is formed through the inter-diffusion of Al and Fe atoms in the interface between the melt and the mold. The low content of Fe in Al alloy prevents the formation of the soldering layer during die casting process. We confirmed the effect of Fe in our experimental system, in which the contents were more effective in reducing the thickness of the soldering layer. In addition, Mn was also tested. Mn is important in Fe containing Al alloys because it is well known to modify the Fe added phase from beta-AlFeSi to alpha-AlFeSi in Al alloys. The soldering layer formation process was implemented using a dipping test for 2 h at 953 K. The die mold material used was H13 steel and the Al alloys were manufactured by gravity casting with several different contents of Fe or Mn. The thickness of the soldering layer with H13 and Al alloys increased with the increase of Fe content in the Al alloys. This is because Al has a lower solubility for Fe. As exceed Fe atoms participated in the soldering reaction, the soldering layer appeared to become thicker. The Mn also contributed to increase the intermetallic layer, similar to Fe.