7075 is an aluminium alloy, with zinc as the alloying element. It is strong, with good fatigue strength and average machinability, but is not weldable and has less resistance to corrosion than many other alloys. Its relatively high cost limits its use to applications where cheaper alloys are not suitable.
It is commonly produced in several heat temper grades, 7075-O, 7075-T6, 7075-T651.
The first 7075 was developed by Japanese company Sumitomo Metal in 1936. 7075 was used for the Zero fighter’s air frame of the Imperial Japanese Navy in pre-war times.
As with all aluminium alloys, 7075 has a specific gravity of 2.73 (0.098 lb/cubic inch).
The mechanical properties of 7075 depend greatly on the temper of the material.
Un-heat-treated 7075 (7075-0 temper) has maximum tensile strength no more than 40,000 psi (276 MPa), and maximum yield strength no more than 21,000 psi (145 MPa). The material has elongation (stretch before ultimate failure) of 9-10%.
7075 tech sheet T6 temper 7075 has an ultimate tensile strength of 74,000 – 78,000 psi (510 – 538 MPa) and yield strength of at least 63,000 – 69,000 psi (434-476 MPa). It has elongation of 5-8%.
T651 temper 7075 has an ultimate tensile strength of at least 67,000 – 78,000 psi (462 – 538 MPa) and yield strength of 54,000 – 67,000 psi (372-462 MPa). It has elongation of 3-9%.
7075 is widely used for construction of aircraft structures, such as wings and fuselages. Its strength and light weight are also desirable in other fields. Rock climbing equipment and bicycle components are commonly made from 7075 aluminium alloy. The bicycle industry is also using 7005 and 6061 aluminium alloys. Hobby grade R/C’s commonly use 7075-T6 and 6061 for chassis plates. One interesting use for 7075 is in the manufacture of M16 rifles for the American military.
7075 has been sold under various trade names including Zicral.also Fortal Constructal