Aging hardening of aluminum alloy-fly ash composites

The aluminum alloy (A356.2)-fly ash composites were produced by stir mixing fly ash into aluminum melt. The fly ash added to the melts was 5% by weight. Selected mechanical properties in the as cast and after age hardening of the composites were examined. The microstructure was also examined using optical and transmission electron microscope (TEM). The A356.2-5 wt % fly ash composite castings showed a notable increase in hardness over the base alloy. The aging behavior the A356.2-5 wt % fly ash composite of as well as the monolithic alloy was followed by a measure of hardness and compressive strength as a function of aging time after quenching. The A356.2-5 wt % fly ash composite responds to age hardening in a manner similar to the matrix alloy.