GROWTH RESTRICTION FACTOR EFFECTS NEAR THE SURFACE OF HIGH PRESSURE DIE CAST Mg-Al ALLOYS

摘要

The grain microstructure at the corner regions of the cross-section of high pressure die cast Mg-Al alloys has been compared to those of the core and flat surfaces of the castings, for Al contents between ～5 and 12 mass%, using the electron back scattered diffraction technique. The average grain size at the corner is somewhat smaller than that of the surface for the higher concentrations of Al, and it appears to be controlled by the amount of solute in the same way as in quiescent castings.