How is this manufactured? I'm stumped
How is this manufactured? I'm stumped
(OP)
I'm working on a project that requires a heat sink for a high power LED. The unit shown in the linked images works well, the problem is that I can't figure out how it was manufactured and I need to create something similar but customized to this project.
This heat sink is from a fairly high volume product. The material is aluminum, and it's anodized. The part is not machined, there are very sharp inside corners that they would never bother with since they serve no purpose. There is 0deg draft on any of it, so it's not die cast. As far as I know you can't metal injection mold aluminum, so that's ruled out. There's no way a high volume part would be sand cast.
Am I missing something? Is there some sort of automated high volume equivalent to sand casting? The bottom face is smoothed with a secondary operation, but the rest of it can be a bit rough. I have Googled everything I can think of with no success.
Any ideas?
http://files.engineering.com/getfile.aspx?folder=4...
http://files.engineering.com/getfile.aspx?folder=e...
http://files.engineering.com/getfile.aspx?folder=9...
This heat sink is from a fairly high volume product. The material is aluminum, and it's anodized. The part is not machined, there are very sharp inside corners that they would never bother with since they serve no purpose. There is 0deg draft on any of it, so it's not die cast. As far as I know you can't metal injection mold aluminum, so that's ruled out. There's no way a high volume part would be sand cast.
Am I missing something? Is there some sort of automated high volume equivalent to sand casting? The bottom face is smoothed with a secondary operation, but the rest of it can be a bit rough. I have Googled everything I can think of with no success.
Any ideas?
http://files.engineering.com/getfile.aspx?folder=4...
http://files.engineering.com/getfile.aspx?folder=e...
http://files.engineering.com/getfile.aspx?folder=9...





RE: How is this manufactured? I'm stumped
http://www.electronics-cooling.com/2007/08/design-...
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RE: How is this manufactured? I'm stumped
You can investment cast Aluminum. and do modified die casting. See IRstuff's second link electronics cooling etc.,
B.E.
)
You are judged not by what you know, but by what you can do.
RE: How is this manufactured? I'm stumped
Those fins could be extruded and sheared to length at a pretty decent rate.
... then bonded or brazed to the contact plate, using a positioning fixture of some kind.
I can't quite eliminate impact extruding the whole thing from a slug a little thicker than the contact plate, but I'd expect a little bigger radius at the root of the fins.
... or maybe the part is smaller than I imagine it; there's no dimensional context in the photos.
The finish texture looks like a fine powder coat that wasn't sintered quite enough to make it run.
Or, the finish texture could be an artifact of selective laser sintering of the whole thing from aluminum powder. ... but I can't imagine that being fast enough for production, unless someone found a way to make it deposit metal as fast as flame/arc spraying.
... If I had one guess as to how the part in the photo was made, I'd go with SLS, and not real fast.
For a low-tech contrast, ISTR that at least some radial engine cylinder heads of WWII vintage had their super-fine fins cut from solid forgings by mechanical reciprocating hacksaws. ... a technology which is not amenable to the exact geometry you've illustrated, but offers a possibility.
Mike Halloran
Pembroke Pines, FL, USA
RE: How is this manufactured? I'm stumped
Looking at the photos, another possibility might be making the part using sintered aluminum powder.
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
(Sorry about the lack of scale, FYI it's about a 3" diameter)
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: How is this manufactured? I'm stumped
While not suitable for truely high volume work (Rubber) Plaster Molding might be able to make that part (not 100% sure about the fin depth ratio).
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
However, if you need to do prototyping it may be of use, I've dealt with these guys before http://aljcast.com/ but there are other places too.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
I have used them for prototype qtys and am just getting into production volumes in the mid 100's. They should have no problem with 5000 pcs lots.
They also have state side reps that are very responsive.
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
I’ll bet you could take a piece of 3"x3" bar stock, say 2' long; mill 1/8" slots every 1/4" o/c along the length; mill the slots 2.8-2.9" deep, with a round toothed saw blade; heat the continuous side sufficiently to form the entire bar around a piece of 2" pipe, without significant cracking in the continuous material. Then oven braze the whole formed doughnut to a base plate.
RE: How is this manufactured? I'm stumped
Shell casting
www.tynevalleyplastics.co.uk
It's ok to soar like an eagle, but weasels don't get sucked into jet engines.
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
We used Radian in the past too, it actually turned out they were just reselling the Malico heat sinks (at a significant mark up).
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
RE: How is this manufactured? I'm stumped
I'm familiar with the squeeze casting process used to produce larger aluminum components, like wheels, using higher strength alloys that cannot be made using conventional casting processes. The "forging" process used here seems like it might be similar. The aluminum preform is heated to a plastic condition (just below its melting point), and then it is rammed into a steel mold under high pressure. The primary limitation appears to be the total mass of the material being forged. It seems to be limited to parts weighing just a few ounces.