Soften aluminum

[lead chucker]

I had some .016 thousands aluminum for gas checks and they wouldn't stay on that good. Too springy. Had a guy tell my how make it softer. I took a torch and heated it up for a couple seconds and could not believe how soft it made it. The material cut easier and the checks have like zero spring and are on real tight can't budge them. So any one here that has some springy aluminum material just take a torch and heat it up good. Worked for me. Just thought I would share this with every one.

[LeadBrain]

Thanks for the Tip!

[ReloaderFred]

I'm looking for the temperature needed to anneal large amounts of aluminum. I have a ceramics kiln that I use for annealing brass for swaging, so it would be simple, as long as I know what temperature to bring it up to for the aluminum, since aluminum melts right above the annealing temperature.

Fred

[yonky]

Fred, i have large aluminium coils annealed the guy who does it has told me he heats up to 716 to 788 degrees fahrenheit for four hours. hope this helps .Ian

[Reload3006]

Annealing



Adjoining crystals within alloy structures can “slip” against each other along “slip planes” as the material is loaded or cold worked. An alloy in which slippage of the crystals has not yet occurred is found to be soft. As that soft metal is cold worked (hammered, rolled or stretched, all at room temperature) then adjoining crystals will move along a slip plane. Each slip plane has a limit to the amount of movement available and so further working will result in successive slippage along other planes. As more work is applied to the metal, the resistance to movement increases greatly and the material is said to “work harden”. Over-working will eventually cause the metal to fracture.

The original workability of the alloy can be restored by heating the material to a point where a new crystal structure forms, complete with a new set of unworked slip planes. The critical temperature at which this occurs in an alloy is called the Recrystallization point and the process is called Annealing.



Another critical factor in achieving correct annealing is the Soak Time. This is the minimum time over which the alloy must be held at the designated temperature for full Recrystallization to occur. The required Soak Time is dependent on alloy type and material thickness.



Annealing is usually carried out in an air furnace and can be used to remove the effect of Cold Working non-heat treatable alloys or to remove the effects of Heat Treatment and Cold Working from heat treatable alloys. Following the annealing operation, aluminum alloys are designated as being at condition “0”, e.g., 2024-0.



Note:

To change from Fahrenheit to Celsius subtract 32 and multiply by .5555

To change from Celsius to Fahrenheit multiply by 1.8 and add 32



The full annealing process includes:



a. Heat to a pre-determined temperature



b. Soak at temperature for specific time



c. Cool in still air or at fixed cooling rate in the furnace



The following Tables quote temperatures, soak times and cooling methods for typical alloys, as recommended by The Aluminum Association:



Table 1

To Anneal Heat Treated Material



Alloy




Soak Temperature




Soak Time (hr)




Cooling Rate



2017

2024

6061

7075




413° C or 775° F

413° C or 775° F

413° C or 775° F 413° C or 775° F




2-3

2-3

2-3

2-3




(a)

(a)

(a)

(b)



Table 2

To Anneal Cold Worked Materials





Alloy




Soak Temperature




Soak Time (hr)




Cooling Rate



2017

2024

6061

7075




343° C or 650 F

343° C or 650 F

343° C or 650 F

343° C or 650 F




2-3

2-3

2-3

2-3




(c)

(c)

(c)

(b)





Cooling Rate Notes:



a. Cool at 28°C per hour from the annealing temp down to 260°C. Subsequent rate is unimportant.



b. Cool at uncontrolled rate down to 232°C. Soak for 4 hrs at 232°C followed by air cooling to room temperature.



c. Cool at uncontrolled rate in air.



To avoid costly heat treatment process prior to forming operations, materials are often procured in the Annealed (-0) condition. Even though some local work hardening may then occur during forming, to achieve full and homogeneous material strength, Heat Treatable alloys must next be Solution Heat Treated and Aged.

[ReloaderFred]

Thank you yonky and Reload3006. I understand what annealing does, just didn't know the proper temperature.

I'll crank up the kiln and give it a try. I've used the torch method in the past, but it's pretty hit and miss, and certainly wasn't precise. The kiln should make it more controllable.

I don't know what the alloy of my aluminum roof flashing is, but it's too hard to form gas checks from as is. The material tears when forming the cup, but the small amount I annealed in the torch formed perfect checks.

Fred

[Reload3006]

I would bet (lol and probably lose) that its 6061

[yonky]

Fred,i have seen a sample of your us flashing and found it to be very hard and brittle ,probably high in magnesium and silicon,the coils i was referring to were .048"thick 1050 h14 (half hard) 99% pure. annealed to soften it for use in electric motors.
so im not sure whether those temperatures apply now'
strangely enough the roof flashing we use over here is 1050 soft (.020") thick
ian

[lead chucker]

All I did was take a test piece about three inches x a foot. It's what I had. And laid it on the cement floor and ran a torch over it a couple times. The material is so thin this that it doesnt take much to heat it up. If you don't have any fancy equipment just experiment with a couple small pieces. The Stuff I tried is just flashing I got from the local lumber yard. It's about 15-16 thousands.

[Sonnypie]

I'm lazy.
I want to try coil annealing in the self cleaning oven.
Just put a coil in a cast iron pan, set it in the oven, and run a cycle.
The wife's oven has 3 different possible settings for self cleaning mode.
I'm thinking a method anybody can use, that is repeatable. [smilie=p:

[Reload3006]

I'm lazy.
I want to try coil annealing in the self cleaning oven.
Just put a coil in a cast iron pan, set it in the oven, and run a cycle.
The wife's oven has 3 different possible settings for self cleaning mode.
I'm thinking a method anybody can use, that is repeatable. [smilie=p:

that is how I anneal rimfire hulls for boolit jackets. works pretty good.

[Sonnypie]

Well then, next time you bake a batch, toss in some abloominum and tell us if you get into trouble with it. :roll:

[fishin_bum]

I bought a couple gas check makers off ebay a few years ago .22 cal and .30 cal it was advertised to use pop cans, I found these to be a little light so I played around with a few different types of metals and came up with vegetable can lids they came out the same size and weight as Lyman gas checks. The bottoms of the cans are no-longer the same as the tops so I just use the lids. And this is another FREE reloading supply.