Why must rivets of a 2017 aluminum alloy be refrigerated bef

Why must rivets of a 2017 aluminum alloy be refrigerated before they are used?

Please show equations used and calculations thank you for your help!!!

Solution

they are made to be refrigerated before it to be used as after the solution is heat treated their precipitation becomes too hard even at room temp and as its precipitation gets hardened they become too strong as well as brittle to be used. that is what makes the rivets of a 2017 aluminium alloy to refrigerate to before it is used.