si 0 19 by weight mg and the balance al and inevitable impurities cast under the conditions of the present invention the al u2014 mn alloy had a solidus temperature of 1190 u00b0 f 643 u00b0 c and a liquidus temperature of 1215 u00b0 f 657 u00b0 c the al u2014 si alloy had a solidus temperature of 1070 u00b0 f 576 u00b0 c and a liquidus temperature of 1080 u00b0 f 582 u00b0 c the al u2014 si alloy was fed into the casting mould such that the upper surface of the metal was maintained so that it contacted the al u2014 mn alloy at a location where a self supporting surface has been established on the al u2014 mn alloy but its temperature was between the solidus and liquidus temperatures of the al u2014 mn alloy a clear interface is present on the sample indicating no general mixing of alloys but in addition particles of intermetallic compounds containing mn 85 are visible in an approximately 200 u03bcm band within the al u2014 si alloy 82 adjacent the interface 80 between the al u2014 mn and al u2014 si alloys the intermetallic compounds are mainly mnal 6 and alpha almn fig1 is a microphotograph at 200 u00d7 magnification showing the interface 80 of the same alloy combination as in fig1 where the self surface temperature.