China is the country with the highest output of 6um-7um aluminum foil in the world. In 2009, it produced more than 150kt of aluminum foil in this thickness range, of which more than 70kt was exported. At present, more than 90% of the 6um-7um aluminum foil produced in the domestic market is made of 1235 alloy, and some double-zero foil manufacturers have begun to use 8079 alloy, while the European and American markets generally use 8079 alloy.

The chemical composition of 🔗1235 alloy and🔗8079 alloy are the same except for the content of Fe element. The Fe element content of 1235 alloy is 0.5-0.6, while that of 8079 alloy is 0.85-0.95, and the Si content of both alloys is 0.07-0.09.

The billets are produced by ingot hot rolling. The two alloys adopt the same ingot homogenization process, and then rolled on 1+4 hot rolling equipment. The thickness of the hot-rolled finished products is 2.8mm-3mm.

In the cold rolling process, it is rolled to a thickness of 0.28mm-0.30mm in 3 passes, and the same intermediate annealing process is adopted when rolling to a thickness of 0.5mm, so as to finally obtain the thickness of 0.28mm-0.30mm in the H14 state. Aluminum foil stock. In the foil rolling process, it is rolled to 0.015mm-0.017mm in 3 passes, then the coils are closed, and a low-temperature intermediate annealing is performed, and the low-temperature intermediate annealing process is the same.

Then carry out the last pass of rolling to the finished product thickness of 0.006mm-0.007mm. After slitting into finished product specifications, the final product annealing is carried out, so as to finally obtain a degreased and clean aluminum foil in the О state, and the final product annealing process of the two alloys is also the same.

(1) For 6um aluminum foil, the average pinhole number of 8079 alloy is significantly less than that of 1235 alloy; the average number of broken ends in the foil rolling process is significantly higher than that of 1235 alloy. In terms of performance indicators, the average tensile strength of 8079 alloy is more than 10MPa higher than that of 1235 alloy, and the elongation is slightly higher than that of 1235 alloy.

(2) For 7um aluminum foil, the number of pinholes of 8079 alloy is slightly more than that of 1235 alloy, but the difference between the two is not obvious; while the average number of broken ends in the foil rolling process is still that 8079 alloy is higher than that of 1235 alloy. In terms of performance indicators, there is the same regularity as that of 6um aluminum foil.
The main difference between the 6um-7um aluminum foil produced by 1235 alloy and 8079 alloy is that the performance index of 8079 alloy is significantly higher than that of 1235 alloy, and the number of pinholes of 6um aluminum foil produced by 8079 alloy is also significantly less than that of 1235 alloy.