Why are aluminum alloy rivets stored in the refrigerator?

11.13 Rivets of a 2017 aluminum alloy must be refrigerated before they are used because, after being solution heat treated, they precipitation harden at room temperature. Once precipitation hardened, they are too strong and brittle to be driven.

What is the purpose of heat treatment of rivets before riveting?

Rivets in this material are heat treated, or more expressly, solution treated, in order to get the alloy in its softest condition. This means that when the rivet is used, it is in the best condition to form the rivet head most easily.

What rivet must be kept refrigerated until they are to be driven?

The 2017-T and 2024-T rivets are used in aluminum alloy structures where more strength is needed than is obtainable with the same size 2217-T rivet. These rivets are known as “ice box rivets,” are annealed, and must be kept refrigerated until they are to be driven.

Why are Icebox rivets stored in a freezer prior to driving?

“B” rivets, alloyed with magnesium is identified with a cross on its head. “D” and “DD” rivets are commonly called icebox rivets because they must be heat treated before use. Following heat treating they must be kept in a freezer for no longer than 20 minutes prior to driving.

What alloy code is used for a 1100 rivet?

Aluminum
After the style code is a letter code identifying the material or alloy type: =1100(2S) Aluminum, AD=2117-Aluminum Alloy, F=Corrosion Resistant Steel, etc.

What does heat treating do to aluminum?

After aluminum has been solution heat treated, the elements that dissolved will begin to precipitate out over time. This causes the grains to lock into position, which in turn increases the natural strength of the aluminum and is called aging.

Why are 2024 rivets refrigerated?

Alloy 2017 rivets become too hard for driving in approximately 1 hour after quenching. Alloy 2024 rivets become hardened in 10 minutes after quenching. If these rivets are stored in a refrigerator at a temperature lower than 32° F immediately after quenching, they will remain soft enough to be usable for several days.

What method is used to harden aluminum alloys that are used in aircraft?

Various alloys, including 3003, 5052, and 1100 aluminum, are hardened by cold working rather than by heat treatment. Other alloys, including 2017 and 2024, are hardened by heat treatment, cold working, or a combination of the two. Various casting alloys are hardened by heat treatment.

What is the softest alloy?

1000 Series Aluminum The 1000 series of aluminum is pure aluminum. It is non-heat treatable and very malleable. It finds its way into heat insulators and license plates. Pure aluminum is the softest of the common alloys and used when deep drawing quality is demanded.

What is the softest alloy of aluminum?

Aluminum 1100
Aluminum 1100 is among the softest aluminum alloys and therefore is not used for high-strength or high-pressure applications.