Comparison of Engineering Properties of 7050-T7E73and 7075-T6510 Extrusions for Potential P-3Applications.

摘要

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)