Accession Number : AD0705968

Title :   METALLURGICAL EVALUATION OF 7175-T736 AND 7175-T66 DIE FORGINGS,

Corporate Author : BOEING CO RENTON WASH COMMERCIAL AIRPLANE DIV

Personal Author(s) : Schimmelbusch,H. W.

Report Date : 04 MAY 1970

Pagination or Media Count : 146

Abstract : Die forging alloy 7075-T73 is presently widely employed in Boeing aircraft because of its excellent stress corrosion resistance, but its mechanical properties are about 14% lower than those for 7075-T6 material. Development work by Alcoa on forging alloy 7175 has led to tempers which combine the mechanical properties of 7075-T6 with a high degree of stress corrosion resistance. The Commercial Airplane Group has conducted a metallurgical evaluation on alloy 7175 in both the peak strength T66 temper and the stress corrosion resistant T736 temper. Mechanical, stress corrosion, fatigue, and fracture properties were investigated. The results show that 7175-T736 has excellent stress corrosion resistance with strength that is equivalent to 7075-T6. The T66 temper has even higher strength properties than 7075-T6 but was found to have a high degree of stress corrosion and exfoliation corrosion susceptibility. (Author)

Descriptors :   (*FORGING, *ALUMINUM ALLOYS), MICROSTRUCTURE, MECHANICAL PROPERTIES, CORROSION RESISTANCE, STRESS CORROSION

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE