Engineering Property Comparisons of PM Alloy X7091-T7E69 and im Alloy Forgings

摘要

The engineering properties of powder metallurgy (PM) alloy X7091-T7E69 forgings were compared with those of forgings of the ingot metallurgy (IM) alloys 7075-T73, 7175-T736, 7050-T736 and 7010-T736. The properties considered were: strength, fracture toughness, fatigue crack propagation under constant amplitude and flight simulation loading, stress corrosion crack initiation and propagation resistance, and exfoliation corrosion. The most important findings were: substantially better combination of strength and resistance to stress corrosion and exfoliation corrosion for the PM alloy as compared to the IM alloys; a fracture toughness of the PM alloy lower than or similar to that of the IM alloys; a dramatically low spectrum fatigue crack propagation life for the PM alloy; only minor differences between the IM alloys.