process for the preparation of a moedermateri eel, methods for the preparation of a silici - um - aluminium - gietlegering and voortbrengse len made from this alloy.

摘要

A master composition for modifying the eutectic component of eutectic and hypo-eutectic silicon-aluminum casting alloys comprises an intimate admixture, in powder or compact form, of a) particles of strontium-silicon and, in certain case, b) particles of an aluminous material, e.g., aluminum. The modification of the silicon-aluminum casting alloys is achieved by adding to the alloy while the alloy is in molten form an effective amount of the master composition, e.g., such as to introduce between about 0.005 and 0.4 percent by weight of strontium into said alloy.