Aluminium alloy with highest thermal conductivity 1

[drodrig]

Hi there,

I have designed an aluminium alloy capsules to house some electronics. They are also in between the active cooling system and another part we want to cool down.

Its function is double: on one hand, it shields the electronics from electromagnetic noise and on the other, it conducts the heat.

It doesn't have mechanical/supporting responsibility. Although there are few small threaded holes (M2) and it will be machinned (milling)

What alloy should I use? Shall I go with the purest aluminium possible?

Checking online the best options are 1050A or 6060

Any recommendations?

We plan to go to mass production so price is also important

thank you in advance

 

[metengr]

As far as best TC, I would look at AA 1100. This aluminum is nearly 99% pure, lower cost and is used in electrical connector applications.

 

[drodrig]

Great, very nice advice

thanks

 

[MintJulep]

Do you have quantified numbers for needed heat reduction? Suitability for the environment, and whatever manufacturing process you use is likely to be more important that the minor differences in conduction between grades.

 

[drodrig]

I must recognize I didn't think about the environment

About the manufacturing, the idea is CNC milling them. I understand this is easy with aluminium, isn't it?

thanks

 

[WKTaylor]

Physical properties matching/ the environment are very important, as MintJulep indicated. One element to be very careful about is potential for in-service oxidation... which could affect thermal and electrical conductivity. Also...

What about fabrication? Dead soft aluminum is a pain to cut/drill/bend and keep from warping/distorting... especially when fastened with solid rivets.

A compromise of physical and mechanical properties is advised.



Regards, Wil Taylor

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[tbuelna]

There are a couple things noted in the OP that need more detail.

What type of "active cooling system" are you using? Is it a liquid or air cooling circuit? If it is a liquid cooling circuit, what is the coolant used?

Have you confirmed that an aluminum "capsule" will provide the level of EMI shielding your electronic package requires? And will the material/finish maintain electrical bond performance at all attachment interfaces of the capsule/housing over its service life?

 

[drodrig]

Hi,

We are using ethanol (or water/methanol mixture) for the cooling, which will not be in contact with these aluminium capsules (not the coolant). My colleagues from electronics are happy with the EMI shielding. Aluminium is the only option for us.

What aluminiums are easier to machine? between the ones we have discussed: 1050, 1100 and 6060? There will be M2 threaded holes.

the capsule has an outer box dimmensions of 1 x 1 x 1.4 inches3 - 25 x 25 x 35 mm3

There are few CNC operations to perform, here some pictures:

thank you
regards

 

[btrueblood]

Your CNC shop will be happier with the 6xxx alloys in heat treated form (T6 temper or similar). The 1xxx alloys do not machine as well, being softer and "gummier" (high ductility) and leave larger burrs behind that they will have to deal with.

 

[drodrig]

ok!
so 6060 it is!
thanks