Cooling Can you trust these heatsinks?

[Phryq]

I'm often finding these cheap, awesome looking heatsinks on sites like this

https://m.alibaba.com/product/60633...at.html?spm=a2706.8841146.1998817009.1.HXIoVh


Too good to be true? To me that's the ideal design for heat-sink case.

 

[Kmpkt]

Buy one and tell us?

 

[confusis]

Buy two to ensure they both work!

 

[Broxin]

What do you mean with 'Trust'?
Its aluminium in a shape of a heatsink. What could be NOT ok with it?

You think its made of plastic and sprayed with a silver paint? Now that could be a problem

 

[Phuncz]

I'd worry more about the adhesive not being up to spec, maybe not being (pure) aluminium.

 

[BirdofPrey]

What do you mean with 'Trust'?
Its aluminium in a shape of a heatsink. What could be NOT ok with it?

You think its made of plastic and sprayed with a silver paint? Now that could be a problem

The flatness of the base is important. The more thermal paste is required to fill the gaps, the worse performance is going to be.
Also as @Phuncz mentioned: if it's not not pure aluminum (something like aluminum and steel or whatnot) it won't be as thermally conductive.

I don't think either scenario is THAT likely. it should be fine.

 

[jØrd]

Buy one and tell us?

Buy two to ensure they both work!

Buy 500 or they wont sell it to you (minimum order is 500 pieces)

 

[Curiosity]

Request a sample.
That's how I got the 12mm switch I'm using in my customod mini build, their minimum order was like 1000.

 

[Phryq]

I read that most alloys compared to pure aluminum, the difference in conductivity is negligible... but I think anodizing is a much bigger deal, to increase radiation.

"Surface emissivity limits the amount of heat transfer due to radiational cooling. With 1.0 being perfect (black body) emissivity anodized aluminum is 0.85 and unfinished is 0.05.

Heat transfer due to radiation is proportional to the heat sink surface area exposed to its surroundings and to the temperature rise above ambient (in absolute °K) raised to the 4th power (T sink-Tambient)4. In natural convection on small heat sinks with open fins, and a high benefit from anodization by up to 45%."

https://www.aavid.com/product-group/extrusions-na/anodize

Don't know if you could buy something like the link in the OP, and have it anodized somehow.

Off topic, but see how these guys embed a coper plate into the heatsink?

http://www.alphanovatech.com/en/cat_cst.html#6

What about embedding a 2d vapour chamber into the heatsink?

 

[Kmpkt]

Off topic, but see how these guys embed a coper plate into the heatsink?

I believe what they do is mill two pieces and then cool them both. Because copper contracts more than aluminum as it is cooled, it makes it small enough to fit inside the aluminum piece. Once returned to normal temperature, the core is firmly seated inside the aluminum outer shell and the part can be finished.

 

[Phryq]

I believe what they do is mill two pieces and then cool them both. Because copper contracts more than aluminum as it is cooled, it makes it small enough to fit inside the aluminum piece. Once returned to normal temperature, the core is firmly seated inside the aluminum outer shell and the part can be finished.

An no air pockets? No problem with heat moving between metals?