7178 T7651 aluminum alloy is a zinc-based alloy from the 7xxx series developed for applications requiring very high strength. This alloy is considered one of the high-performance materials used particularly in aerospace and defense industries. The T7651 temper improves resistance to stress corrosion cracking while maintaining high strength through stress relieving and controlled aging processes. Because of these characteristics, 7178 T7651 is commonly selected for structural applications requiring high load capacity and reliability.

In terms of strength and mechanical properties, 7178 T7651 aluminum alloy offers very high tensile and yield strength. Thanks to these properties it can reach strength levels comparable to 7075-T651, while in some applications providing improved resistance to stress corrosion cracking. When compared with 2024-T351 alloy, 7178 T7651 provides significantly higher strength values, although 2024 may offer advantages in fatigue resistance in certain conditions. In comparison with 6061-T6 alloy, 7178 provides much higher strength, whereas 6061 offers better weldability and more versatility for general-purpose applications.

Regarding corrosion resistance and surface properties, the 7178 T7651 alloy is optimized particularly against stress corrosion cracking. With the T7651 temper the alloy demonstrates a more balanced corrosion performance compared with conventional T6 tempers. However, when compared with 5xxx series aluminum alloys its corrosion resistance in marine environments is more limited. Therefore surface protection methods such as anodizing, coating or painting are commonly used. The alloy also shows good coatability and is frequently used with protective coatings in aerospace applications.

In terms of machinability, bending and manufacturing characteristics, 7178 T7651 provides good machinability and can be efficiently processed in CNC machining operations despite its high strength. However, due to this high strength its bending capability is more limited compared with 6xxx series alloys and it is generally not preferred for forming operations requiring large deformation. Regarding weldability, similar to most 7xxx series alloys its weldability is limited and mechanical fastening methods are typically preferred.

Considering vibration behavior and applications, the high stiffness and strength of 7178 T7651 allow it to perform well in structural components subjected to vibration and dynamic loads. For this reason it is widely used in aerospace, defense, space and high-performance machinery components. Aircraft wing structures, landing gear parts, structural fasteners and heavily loaded mechanical components are among the primary applications of this alloy. The combination of high strength, reasonable corrosion resistance and good machinability makes 7178 T7651 an important material in modern engineering applications.

MATERIAL COMPOSITION STANDARDS

7178 T7651 is available according to the following standards:
• 7178 T7651 Sheet; ASTM B209, ISO AlZn7MgCu, UNS A97178, AMS QQ-A-250/14
 

Characteristic Properties of 7178 T7651: 

• Strength: Excellent
• Machinability: Poor
• Weldability: Medium
• Forming: Reasonable
• Corrosion Resistance: Good
• Heat Treatment: Yes
   

Some Well-Known Applications of 7178 T7651: 
High-strength fasteners in the aerospace sector,
External skins of aircraft wings,
Also used in the construction industry.
 

STOCK
We produce/supply 7178 T7651 in sheet/plate form.

• Sheet
• Plate