Alloy 7050 is the premier choice for aerospace applications requiring the best combination of
strength, stress corrosion cracking (SCC) resistance and toughness. It is particularly suited for plate applications in the 3 to 6 inch (76.20 to 152.40mm) thickness range. Alloy 7050 exhibits better toughness/corrosion resistance characteristics than alloy 7075. Because it is less quench sensitive than most aerospace aluminum alloys, 7050 retains its strength properties in thicker sections while maintaining good stress corrosion cracking resistance and fracture toughness levels.
Alloy 7050 plate is available in two tempers: T7651 combines the highest strength with good
exfoliation corrosion resistance and average SCC resistance; and T7451 (formerly T73651) provides better SCC resistance and excellent exfoliation resistance at slightly lower strength levels.
Alloy 7050 sheet is available bare and Alclad in the T76 temper. Alcoa developed alloy 7050 and has been the major supplier of this alloy since the early 1970’s.
strength, stress corrosion cracking (SCC) resistance and toughness. It is particularly suited for plate applications in the 3 to 6 inch (76.20 to 152.40mm) thickness range. Alloy 7050 exhibits better toughness/corrosion resistance characteristics than alloy 7075. Because it is less quench sensitive than most aerospace aluminum alloys, 7050 retains its strength properties in thicker sections while maintaining good stress corrosion cracking resistance and fracture toughness levels.
Alloy 7050 plate is available in two tempers: T7651 combines the highest strength with good
exfoliation corrosion resistance and average SCC resistance; and T7451 (formerly T73651) provides better SCC resistance and excellent exfoliation resistance at slightly lower strength levels.
Alloy 7050 sheet is available bare and Alclad in the T76 temper. Alcoa developed alloy 7050 and has been the major supplier of this alloy since the early 1970’s.
Through the application of statistical process control techniques recently implemented at Alcoa’s
Davenport, Iowa plant, additional quality improvements have been made to thick gauges of 7050
plate. The resulting reduction of microporosity significantly improves the short transverse properties.
This makes Alcoa 7050 plate a good choice where ST loadings are a design factor.
Davenport, Iowa plant, additional quality improvements have been made to thick gauges of 7050
plate. The resulting reduction of microporosity significantly improves the short transverse properties.
This makes Alcoa 7050 plate a good choice where ST loadings are a design factor.
thicknesses are 2 to 6 inches (50.8 to 152.40mm). Typical applications for alloy 7050 sheet include
wing skins. The major usage is in plate applications requiring thicknesses over 2 inches (50.8mm)
where 7050 has superior properties.
7050-T7651 PLATE (ALL GAUGE RANGES NOT SHOWN)GUARANTEED MINIMUM LONG TRANSVERSE MECHANICAL PROPERTIES.
ALLOY 7075-7651 PROPERTIES SHOWN FOR COMPARISON.
7050-T7451 PLATE (ALL GAUGE RANGES NOT SHOWN)GUARANTEED MINIMUM LONG TRANSVERSE MECHANICAL PROPERTIES.
ALLOY 7075-T7351 PROPERTIES SHOWN FOR COMPARISON.
7050-T76 SHEET (ALL GAUGE RANGES NOT SHOWN)TENTATIVE GUARANTEED MINIMUM LONG TRANSVERSE PROPERTIES.
Alloy 7050 is one of a group of controlled-toughness, high-strength alloys as defined by
The Aluminum Association’s Document T-5 (See “References”).
7050-T7651 PLATE (ALL GAUGE RANGES NOT SHOWN)GUARANTEED MINIMUM KIc FRACTURE TOUGHNESS VALUES: ksi√in. (MPa√m)
7050-T7451 PLATE (ALL GAUGE RANGES NOT SHOWN)GUARANTEED MINIMUM KIc FRACTURE TOUGHNESS VALUES: ksi√in. (MPa√m)
In general, the fatigue properties–including fatigue crack propagation–are similar to other
highstrength 7XXX aluminum alloys. For complete data on the numerous tests conducted,
refer to Alcoa Green Letter No. 220.
Long-term controlled and in-service evaluations have shown alloy 7050 plate and sheet products to
maintain equal exfoliation and stress corrosion resistance at higher strength levels compared with
other high strength alloys such as 7075.
The T76 temper of alloy 7050 provides highest strength with excellent resistance to exfoliation
corrosion.
SCC resistance in this temper is adequate for most service applications where sustained tensile
stresses in the short-transverse direction can be controlled to relatively low levels.
The T74 temper (formerly T736) is intended for more demanding SCC applications, such as certain
interference fits or other sustained short transverse loaded structures.
The recommended practices for heat-treating and aging 7050 plate and sheet are described in
MIL-H- 6088, “Heat Treatment of Aluminum Alloys.”
Procedures used for cleaning, anodizing, conversion coating and painting alloy 7050 are generally
similar to those used for alloy 7075.
Forgings, extrusions, and fasteners in Alloy 7050 are also available.
REFERENCES:
Alcoa Green Letter No. 220The Aluminum Association, Position on Fracture Toughness Requirements and Quality Control Testing T-5
MIL-H-6088, Heat Treatment of Aluminum AlloysThe plate tempers shown in the following tables are guaranteed KIc minimum values.
Kc values for sheet are available from your Alcoa sales representative.