Aluminum 7178-T6; 7178-T651

Subcategory: 7000 Series Aluminum Alloy; Aluminum Alloy; Metal; Nonferrous Metal

Close Analogs:

Composition Notes:
This designation is considered the sole original alloy for this alloy family.
Aluminum content reported is calculated as remainder.
Composition information provided by the Aluminum Association and is not for design.

Key Words: UNS A97178; Aluminium 7178-T6; Aluminium 7178-T651; AA7178-T651; AA7178-T6

Component   Wt. %
Al85.3 - 89.5 
Cr0.18 - 0.28 
Cu1.6 - 2.4 
FeMax 0.5 
Component   Wt. %
Mg2.4 - 3.1 
MnMax 0.3 
Other, eachMax 0.05 
Other, totalMax 0.15 
Component   Wt. %
SiMax 0.4 
TiMax 0.2 
Zn6.3 - 7.3 

Material Notes:
Data points with the AA note have been provided by the Aluminum Association, Inc. and are NOT FOR DESIGN.

Physical PropertiesMetricEnglishComments
Density2.83 g/cc0.102 lb/in AA; Typical

Mechanical Properties
Hardness, Brinell160160 500 kg load with 10 mm ball
Hardness, Knoop205205 Converted from Brinell Hardness Value
Hardness, Rockwell A55.355.3 Converted from Brinell Hardness Value
Hardness, Rockwell B9090 Converted from Brinell Hardness Value
Hardness, Vickers189189 Converted from Brinell Hardness Value
Ultimate Tensile Strength607 MPa88000 psi AA; Typical
Tensile Yield Strength538 MPa78000 psi AA; Typical
Elongation at Break10 %10 % AA; Typical; 1/16 in. (1.6 mm) Thickness
Elongation at Break11 %11 % AA; Typical; 1/2 in. (12.7 mm) Diameter
Modulus of Elasticity71.7 GPa10400 ksi AA; Typical; Average of tension and compression. Compression modulus is about 2% greater than tensile modulus.
Compressive Yield Strength530 MPa76900 psi 0.1% Permanent Set
Notched Tensile Strength386 MPa56000 psi 2.5 cm width x 0.16 cm thick side-notched specimen, Kt = 17.
Ultimate Bearing Strength1089 MPa158000 psi Edge distance/pin diameter = 2.0
Bearing Yield Strength807 MPa117000 psi Edge distance/pin diameter = 2.0
Poisson's Ratio0.330.33 Estimated from trends in similar Al alloys.
Fatigue Strength150 MPa21800 psi 500,000,000 Cycles
Machinability70 %70 % 0-100 Scale of Aluminum Alloys
Shear Modulus27 GPa3920 ksi Estimated from similar Al alloys.
Shear Strength360 MPa52200 psi 

Electrical Properties
Electrical Resistivity5.49e-006 ohm-cm5.49e-006 ohm-cm AA; Typical at 68F

Thermal Properties
CTE, linear 68F23.4 m/m-C13 in/in-F AA; Typical; Average over 68-212F range.
CTE, linear 250C25.4 m/m-C14.1 in/in-F Average over the range 20-300C
Specific Heat Capacity0.856 J/g-C0.205 BTU/lb-F 
Thermal Conductivity125 W/m-K870 BTU-in/hr-ft-F AA; Typical at 77F
Melting Point477 - 629 C890 - 1165 F AA; Typical range based on typical composition for wrought products 1/4 inch thickness or greater. Homogenization may raise eutectic melting temperature 20-40F but usually does not eliminate eutectic melting.
Solidus477 C890 F AA; Typical
Liquidus629 C1165 F AA; Typical

Processing Properties
Annealing Temperature413 C775 F 
Solution Temperature468 C875 F 
Aging Temperature121 C250 F for 24 hr

References for this datasheet.

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