Need to anneal 5052 aluminum

[Ryoko]

I need to anneal 5052 aluminum for a home project. Google has given me mixed results on how to do this. Short version is that I'm doing some heavy forming on a piece of 5052-H32 and I'm running into issues with it work hardening. I've tried the Sharpie trick with a propane torch. But I'm not sure this is doing anything. I'm also seeing conflicting opinions whether to quench or air cool. So I'm looking for some expert opinions. (Oven heating is not an option due to size.) Thanks.

edit: The thickness of the metal piece is only .032". So I'm not too worried about heating all the way thru.

 

[jrmichler]

I used search terms 5052 aluminum annealing temperature, and got several good results. Some of the confusion might be due to the way that it starts to soften at 500 deg F, but needs 650 deg F to anneal. That's why some sites mention hot working at temperatures above 500 deg F, and annealing at 650 deg F. A quick search seems to show that air cooling vs quenching makes no difference, nor does hold time at temperature. I suggest that you do some deeper searching (note my use of "seems to show").

 

[Astronuc]

A quick look at the Wikipedia article gives some very basic information, e.g., "5052 is not a heat treatable aluminum alloy, but can be hardened through cold working." For any aluminum alloy, one may find a variety of thermal treatments, usually designated with a T after the 4 digit number. However, some alloys cannot be hardened by thermal treatment. One may hear a term 'age-hardening' or 'precipitation hardening' in which an alloy is annealed (solution annealed), quenched (to precipitate second phase particle in the crystal matrix) and finally aged (to grow the second phase particles). However, not all alloys can be preciptiation hardened, but instead must be 'work hardened'.

There are a variety of texts or handbooks with appropriate information and references. For example,
ASM Handbook, Volume 2: Properties and Selection: Nonferrous Alloys and Special-Purpose Materials ASM Handbook Committee, p 91

One has to be careful though in finding the correct information for a given alloy. One might be able to find product information from a supplier like Reynolds Aluminum or Alcoa, or a trusted supplier.