The zinc aluminum grades are the name given commonly to the 7000 series grade aluminums. As may be obvious, zinc is the largest alloying element incorporated into the aluminum alloy. These alloys represent the hardest and strongest among aluminum grades. Alloy 7068 is the strongest with 7075 being the most commonly used in applications.
Alloy 7075
Aluminum alloy 7075 offers exceptionally high strength. It is stronger than certain types of mild steel. This alloy has a level of strength at the top among common screw alloys. It is an appropriate replacement alloy for 2024, 2017, and 2014 in critical application as a result of its superb corrosion resistance in both the T7351 and T173 tempers. Its great strength also makes it highly suitable for use in the ordinance and aircraft industries.
Alloy 7068 – Ultra-Strength
The ordinance industry requested the development of an ultra-high strength, yet lightweight aluminum at about the turn of the century that would match or exceed the corrosion resistance properties of 7075. Alloy 7068 was the answer to this request. It possesses the highest mechanical strength of all commercially available aluminum alloys at 99 KSI (683 MPa). This gives it a 35% stronger mechanical strength than possessed by alloy 7075. Alloy 7068 is also strong than alloy 6061 by a factor of 2.5.
As indicated previously, aluminum alloys has a mechanical strength that exceeds that of many types of steel. Pre-hardened stainless steel (HRC 26-32) in the 400 and 41XX series and aluminum alloy 7068 have nearly the same yield strength; but alloy 7068 only has about 33 percent of the weight of the aforementioned stainless steel. Alloy 7068 surpasses virtually all current engineering alloys in terms of its strength-to-weight ratio. Its performance is one-third better than 7075. It delivers an enhanced strength-to-weight performance – 33% better – than 7075 and a better strength-to-weight performance – 28 % better – than 6Al-4V Grade 5 titanium.
It has higher cost (3 to 4 times that of 6061) and limited availability, making its use limited for commercial projects.
Beyond the initial request for its use in the ordinance industry, other consideration for its use or other actual uses of this alloy are for the medical device, automotive, recreational product, and aerospace industries.
Contact an experienced aluminum alloy supplier today to learn about the options we offer in aluminum alloys and products for your application.
