Modification of aluminium-silicon alloys in metal matrix composites

摘要

A process is described for forming a composite cast article comprising an aluminum-silicon alloy matrix containing strontium as a modifier and a preform of bonded-together Al₂O₃ fibres incorporated in the matrix, in which the preform is infiltrated under pressure by a melt of the alloy and the composite article thus formed is allowed to solidify by cooling. According to the novel feature, by utilizing a specific amount of strontium as modifier in the range of about 0.5 to 1.0% by weight, it is possible to obtain a satisfactory modification of the alloy within the composite.