STRUCTURE AND PROPERTIES OF SPRAY FORMED 7150 CONTAINING FE AND SI

A 7150 aluminum alloy containing 0.6w/o Fe and 0.5 w/o Si was spray de posited using the rapid solidification process Liquid Dynamic Compacti on (LDC). After deposition, the spray-deposited preform was hot rolled to full density. Tensile and fatigue specimens were machined from the rolled material and then heat treated to the T6 temper Tensile tests revealed that the LDC 7150 + Fe/Si material possessed lower strength a nd ductility than control specimens of commercial high purity ingot-ba sed 7150 sheet. The lower strength of the LDC material was attributed to the gettering of Cu by the high Fe content Fatigue crack growth rat es for the LDC 7150 + Fe/Si material proved to b6 significantly less t han for the commercial alloy. This was explained on the basis of the L DC specimen's larger grain size and higher volume fraction of constitu ent particles as they relate to the mechanism of roughness-induced cra ck closure.