Annealing Aluminum Sheet Metal

By annealing the metal beforehand cold working can take place without any risk of cracking as annealing releases mechanical stresses produced during machining or grinding.

Annealing aluminum sheet metal.

Machining operations that create high amounts of heat or material displacement may also warrant an annealing process afterward. Metal wire that has been drawn from one size to a smaller size may also undergo an annealing process. Partial annealing like this though will give you the ability to form it more easily without it cracking. It s especially useful if you need to cut something that s been welded up like when you need to repair stripped threads on a shaft.

Annealing is used for steel however other metals including copper aluminum and brass can be subject to a process called solution annealed. If you try to anneal aluminum without cleaning the surface you will get to the stage when heating where the surface looks solid because of the surface oxides but the inside will be turned into a liquid meaning the piece you are heating will collapse once the surface tension is destroyed and you will have it quickly turning into a blob of aluminum. This can make it easier to form or machine. Metal is made up of a crystalline structure which directly relates to its mechanical properties.

This technique also only works on sheet metal or very thin parts. Annealing is a heat treating process that softens steel. Annealing removes what s called residual stress. Annealing can also improve a metal s ability to be machined and improve the lifespans of tools.

The metal is heated 650 825f held for a good soak and then cooled very accurately at the rate of 50f per hour until the temperature is 400 500f depending on the alloy and then the rate of cooling is unimportant. Hard brittle metals can cause wear to shop tools. It involves heating the steel to 20 50 c above its upper critical point soaking it for a short period at that temperature and then allowing it to cool in air. The metal is heated above its recrystallization temperature maintained at this temperature and then cooled in a controlled environment.

Work hardened materials such as sheet metal that has undergone a stamping process or cold drawn bar stock. Annealing metals reduces wear and the chance of damage to tools. The heat needs to soak through the metal. Annealing heat treatable aluminum alloys is accomplished again by heating and cooling but in a different procedure.