Previous work with 354-T6I, an aluminum-silicon-copper—magnesium casting alloy, had demonstrated a mechanical property advantage over the 356 variant-T6 aluminum alloy currently used in Douglas production. This advantage was confirmed. Optimumly heat treated, 354-T6 aluminum alloy showed a five to ten percent advantage in iron chill-cast ultimate and yield strength and a 20 to 35 percent advantage in part strength.nThe part strength levels achieved were comparable to the identical. Tee shaped configuration machined from wrought 1.5 inch thick 7075-T6 aluminum alloy plate and considerably in excess of values obtained with 20I4-T6.
展开▼
