Accession Number : ADA058002

Title :   Comparison of Engineering Properties of 7050-T7E73 and 7075-T6510 Extrusions for Potential P-3 Applications.

Descriptive Note : Final rept. 30 Nov 76-27 Feb 78,

Corporate Author : LOCKHEED-CALIFORNIA CO BURBANK

Personal Author(s) : Brodie,Roy W. ; Bakow,Leon

Report Date : FEB 1978

Pagination or Media Count : 111

Abstract : 7050-T7E73 extrusion material was procured in P-3 wing spar cap and plank shapes for direct comparative testing with current 7075-T6510 production extrusions. Three lots of 7050-T7E73 were produced and processed in production facilities to be representative of actual part fabrication. Comparable 7075-T6 tensile strengths and improved exfoliation, and fatigue properties were obtained with the 7050-T7E73 material. Significant improvements were obtained in crack propagation in approximately 40% R.H. and approximately 98% R.H. environments where the crack growth threshold showed an approximately 30% increase and the crack growth rate was approximately 67% slower for the 7050-T7E73 material. The 7050-T7E73 also had a 60 to 70% improvement in fracture toughness at room temperature and -65 F over the 7075-T6510 material and the -65 F toughness of 7050-T7E73 was 30% higher than the room temperature toughness of 7075-T6510. (Author)

Descriptors :   *ALUMINUM ALLOYS, TENSILE PROPERTIES, EXTRUSION, TOUGHNESS, HIGH STRENGTH ALLOYS, FRACTURE(MECHANICS), HEAT TREATMENT, CRACK PROPAGATION, AIRFRAMES, FATIGUE(MECHANICS), CORROSION RESISTANT ALLOYS, PATROL AIRCRAFT, STRETCH FORMING, EXFOLIATION.

Subject Categories : Patrol and Reconnaissance Aircraft
      Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE