The tensile strength of aluminum alloy is better than many alloy steels, and it is an ideal structural material. The typical materials used in mobile phones are 6063 aluminum alloy and 7075 aluminum alloy.
The Apple iPhone 6 and iPhone 6 Plus are 6000 series aluminum bodies, while the iPhone 6S and iPhone 6S Plus and iPhone 7 are 7000 series aluminum bodies.
6000 series aluminum-magnesium-silicon alloy, mainly containing magnesium and silicon, which combines the advantages of 4000 series and 5000 series. The 6000 series is a cold-processed aluminum forged product, which is suitable for applications requiring high corrosion resistance and oxidation resistance. Good workability, easy coating and good processability. Among them, 6063 aluminum plate has medium strength, the surface is smooth and beautiful, the flatness is good, and it is not easy to be deformed after processing.
With the demand for thinner and lighter mobile phones, the strength of aluminum alloys has been gradually amplified, turning to higher-strength aluminum alloys such as 7000 series aluminum alloys.
iPhone 6s and iPhone 6s plus use Apple's custom 7000 series aluminum-zinc-magnesium alloy, which mainly contains zinc. It belongs to the aviation series and is a heat treatable alloy. It is a super-hard aluminum alloy with a hardness 60% higher than ordinary aluminum and the density is reached. One-third of stainless steel while still maintaining a light weight.
Apple said that the custom-made 7000 series aluminum-zinc-magnesium alloy can be processed, polished and micro-zirconia beads blasted to achieve a consistent satin texture, while an additional anodizing process helps prevent scratches and corrosion.
The advantages of aluminum alloys over stainless steel are even more pronounced. The texture of the aluminum alloy metal is very strong, and the aluminum alloy material is easier to process the high-grade and beautiful feeling compared with the dullness of the stainless steel. Moreover, the aluminum alloy material is very light and has a specific gravity of about one-third that of stainless steel. In addition, aluminum alloy materials have strong dyeability, and because of the replacement of aluminum alloys, there are colors such as “local gold”, “high-end gray”, “rose gold” and “bright black”. At the same time, aluminum alloy materials also have many advantages such as high temperature resistance, no fingerprints, antistatic, environmental protection and non-toxicity. Therefore, this material is often used in aerospace, marine, automotive, medical and other fields.