cnc plate thickness

[imagineers]

I am trying to cnc a plate and get it made in China, they came back with a comment mentioning there could be some deformation possible in the red area, which is 1.3mm thick. This is made from aluminum. 10" x 3.5" wide. thoughts?

 

[CoryPad]

Use stress relieved/annealed material to avoid excessive distortion from residual stresses.

 

[imagineers]

like what annealed steel? I need aluminum for heat transfer

 

[mfgenggear]

imagin
what is the aluminum and what is the final heat treat condition?
if it is heat treatable aluminum. it would be wise to mill it in the annealed condition then heat treat after it is finished machined. use graphite flat plate to keep it flat during the heat treating.

you do not give enough information. we are guessing at the material condition.

Mfgenggear

 

[KENAT]

Depending on mechanical properties required you could consider some kind of continuous cast plate such as MIC-6

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(probably not aimed specifically at you)
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[CoryPad]

You need to get your aluminum annealed or stress relieved.

 

[JNieman]

Stress relieving 6061/7075, etc, will make a difference, definitely. It's not as severe as cold rolled steel and other stressed materials but aluminum certainly can have issues crop up in specific situations where yours likely falls.

For a part such as this, I think the suggestion to use tooling plate such as MIC-6 is a very good idea.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5

 

[racookpe1978]

Use more cooling and a slower feed rate, cutting depth, and cutter head speed. But - that will increase time for each piece, and possibly affect the surface finish.

Ain't it "fun" and "cheaper" trying to get the work done overseas? /sarcasm

 

[tomwalz]

I guess I would figure on having the plate reworked after you got it.

I looked at the picture and I think I would go with whomever could make me good parts rather than looking for a low price.

I don't think I would fly the parts back either.

By the way, how much deformation is allowed?



Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[Timelord]

Have you tried cast tooling plate? It is designed to be real stable. Like this stuff:

(quote) MIC6® Aluminum Cast Plate
The Best of the Best
MIC6® Aluminum Cast Plate is a blend of the most desirable features of many individual metals. The result is a cast aluminum plate that meets the challenge of product accuracy demanded by today's industry.

Because of its cast granular structure and stress relieving properties, MIC6® Aluminum Cast Plate allows high-speed metal removal with little, if any, of the distortion commonly inherent in long grained wrought, flat-rolled metals.

Using proper aluminum machining methods, tolerances in the thousandths can be consistently maintained. MIC6® Aluminum Cast Plate is finished to 20 microinches typical on both sides. Thickness tolerances is within +/-.005" from nominal on 1/4"- 4".

Flatness tolerance is maintained within .015" on 1/4"-5/8" thickness and .005" on 3/4"- 4" thickness. Thermal Cycling can be performed up to 800° F under controlled conditions.

MIC6® Aluminum Cast Plate is produced by continuous casting with each thickness individually cast. By utilizing the most recent developments in casting techniques, the molten metal is continuously fed, eliminating defects from lapses and seams. Thermal gradients are stabilized since heat is removed from both plate surfaces at a balanced rate. The employment of a SNIF filtering and degassing system ensures an end product free of voids and impurities.

Timelord

 

[imagineers]

So there seems to be a consensus to use the MIC-6. Material hasn't been chosen. So this mic-6 can it be anodized like regular aluminum? I know you can't really anodize cast but this will be strictly machines for samples.

 

[MikeHalloran]

Annealed or tempered makes no difference to the heat transfer.

The part looks basically like a fancy shim. ... meaning that if you install it in a soft/annealed state, thickness matters but flatness doesn't, because the mating parts will iron it out.

Annealed aluminum is pretty gummy, so I'd be inclined to buy it in a T4-ish or harder condition, machine it in a vacuum chuck or temporarily bonded to a thick flat plate, dimension it for uniform thickness over each feature, allow a large range in flatness, and have it annealed to -O or nearly so.


Your Chinese competitors, probably already tooling up, will likely even simplify the part to eliminate machining, possibly by coining the groove, possibly by splitting the part parallel to its major plane, making it a couple of stamped blanks.


Mike Halloran
Pembroke Pines, FL, USA

 

[KENAT]

MIC-6 doesn't Anodize especially well. I've only tried having it anodized black (may have been hard - I can't remember) and it came out kind of 'blotchy' (actually quite an attractive pattern but not what we wanted to match other black anodized components).

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Timelord]

I can verify Kenat's post. I had a MIC6 plate hard anodized with no dye and the result was a blotchy grey. Not entirely unattractive, but hard to match. I was after the hard surface and didn't care about appearance.

Timelord

 

[John2025]

We use MIC-6 and I love it for certain applications, but be careful, it's cast and acts like it. Weak, soft and cracks easily in my experience. I wouldn't use it for something thin unless I knew it was going to be very well supported.

 

[MintJulep]

Anodize will affect conducted heat transfer.

I would make that thing out of two layers.

 

[capnhook]

I could imagine making it here in th ol'SA

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