https://wccftech.com/2022-iphone-14-pro-max-to-use-titanium-alloy-chassis/

For 2022, Apple might shift away from an aluminum chassis and stainless steel build for its premium iPhones and introduce a titanium alloy chassis for the iPhone 14 Pro and iPhone 14 Pro Max. There would be several benefits to using such a material combo, so let us discuss this at length.

A JP Morgan investors note states that using a titanium alloy chassis will be one of the biggest aesthetic changes arriving to the iPhone 14 Pro and iPhone 14 Pro Max. For 2022, Foxconn will reportedly be Apple’s biggest manufacturing partner of titanium frames, but it is unclear what materials the remaining two members of the iPhone 14 will use. Assuming the company sticks with aluminum and glass, we might see the two being used for the remaining models.