Warning To All Using Ax478 Heatsinks

The Spyder · 09-15-2002, 05:18 PM

Ok...... i was getting bad temps with my thermalright Ax478 and any fan..... so i just stoped using the computer for a while...... and today..... i look at my window..... and i see the fins and fan of my heatsink resting onto of my GF4..... i think humm...... look at the cpu........ look- theres the copper base plate.... AWW ****! It broke off from the Copper plate!!! Thankfully i wasnt using it..... but this thing did nothing but run a 2.26 at stock for less then 2 days!! WTF??

Heres some pics.....
http://www.theforumisdown.com/upload...sHitz_0002.jpg

Brad · 09-16-2002, 03:12 AM

very scary - I can only hope it was a one off mistake. Better get the rma underway....

RoboTech · 10-05-2002, 10:00 PM

I have been using a lot of AX-7s with great results. I have often wondered how Thermalright bonds the aluminum body to the copper base? I assume it is a thermal epoxy (sorta like AS epoxy?). I don't know of any solder/flux combo for Cu-AL???

Does anyone know for sure how Thermalright bonds the Al to Cu??? Thanks,

RoboTech

Jorde · 12-10-2002, 11:23 AM

Quote:

Originally posted by RoboTech
I have been using a lot of AX-7s with great results. I have often wondered how Thermalright bonds the aluminum body to the copper base? I assume it is a thermal epoxy (sorta like AS epoxy?). I don't know of any solder/flux combo for Cu-AL???

Does anyone know for sure how Thermalright bonds the Al to Cu??? Thanks,

RoboTech

They solder aluminium fins to copper base, simple

The Spyder, god damn what kinda luck you have

First time I hear about anybody messing with their AX-serie coolers. I have a AX-7 and now I'm using SLK-800, both damn great coolers.

Since87 · 12-10-2002, 11:54 AM

This appears to be a very bad design.

Due to the difference in the coefficients of thermal expansion for copper and aluminum. Repeated thermal cycling of the heatsink will rip the solder joint apart.

The coefficients of thermal expansion are:

Copper - 17ppm/K

Aluminum - 25ppm/K

Some more info here.

hara · 12-10-2002, 01:28 PM

can copper be fused to al?

phreenet · 12-10-2002, 02:49 PM

In order to solder Al to Copper you need a transition metal, like a steel.

RoboTech · 12-20-2002, 09:47 PM

Someone told me recently that the aluminum body on the AX-7 is tin plated, which allows it to be soldered to the copper base. That sounds plausible... ??? and I've noticed the AX-7s do look like they have some sort of plating.

Anyone else heard this?

lukasz70 · 01-17-2003, 11:10 PM

Quote:

They solder aluminium fins to copper base, simple

you cant solder exposed (not plated with anything) aluminium to anything!,

Quote:

Someone told me recently that the aluminum body on the AX-7 is tin plated, which allows it to be soldered to the copper base. That sounds plausible... ???

this would explain it, but if it was soldered it wouldn't/shouldn't come apart,

jaydee · 01-18-2003, 12:11 AM

Quote:

Originally posted by lukasz70
you cant solder exposed (not plated with anything) aluminium to anything!,

Then how did I pull this off? Copper fitting to AL top.

Must have been extream luck?

lukasz70 · 01-18-2003, 10:57 AM

WT*, how did you pull that off?
i got my info from someones thats been welding/working with metal for over 30 years, and as far as they know, you cant solder alu, i'll show them that pick and see what they have to say about it.

i did find this link though on soldering alu http://www.ganoksin.com/orchid/archi...8/msg00348.htm

bigben2k · 01-18-2003, 02:18 PM

It's not impossible to solder aluminium, but it is difficult: First, it melts extremely easily, and as the link states, form an oxide. Much practice required.

lukasz70 · 01-18-2003, 08:17 PM

k, asked my dad again about alu,
apperantly you can weld alu only to alu using MIG and TIG, but you cant weld other metals to it unless its plated.

as for soldering, its like the link says "there HAVE been several solder formulations developed for aluminum, each with it's own specific type of flux". but I doubt that these are available at your local hardware store,

jaydee · 01-19-2003, 09:09 PM

I have been a certified stick and wire feed welder for 7 years now. Been in fabrication and erection for 8. Sheet metal and heavy steel. Just in the last few months got transfered to the boss's other company to run the engraving shop. I have soldered AL to AL with just flux and solder from Home Depot. It is a royal pain but if you have patients and hit the heat levels at the right moment it can work but rarely done. It is just to much a pain in the ass.

Also in reference to the pic I posted, if you can get the solder to actually stick to the al your set. I did that and then solder a little onto the copper fitting and heated both peices up to where the solder was liquide and touched them together. It is a bitch to do. it took a couple hours but I was determined. Since swappedthat out for a read barb.

09-16-2002, 03:12 AM	#2
Brad Thermophile Join Date: Oct 2001 Location: Nuu Zeeelin Posts: 3,175	very scary - I can only hope it was a one off mistake. Better get the rma underway.... __________________ 2x P3 1100's at 1400, Abit VP6, 2x Corsair 256mb PC150 sticks, 20gb 'cuda ATA-III, 2x 40gb 'cuda ATA-IV in raid 0. 20" Trinitron. No fans 2x 2400+ at 2288mhz (16.0 x 143), Iwill MPX2, 2x Kingmax PC-3200 256mb sticks, 4x 20gb 60gxp in Raid 5 on a Promise SX6000. Asus Ti4200 320/630. Cooled by Water

12-10-2002, 02:49 PM	#7
phreenet Cooling Savant Join Date: Feb 2001 Location: Gloucester, Virginia Posts: 356	In order to solder Al to Copper you need a transition metal, like a steel. __________________ Dual Pentium!!! 933@1107 Liquid Cooled.

01-18-2003, 10:57 AM	#11
lukasz70 Cooling Savant Join Date: Nov 2002 Location: Ontario. Canada Posts: 159	WT, how did you pull that off? i got my info from someones thats been welding/working with metal for over 30 years, and as far as they know, you cant solder alu, i'll show them that pick and see what they have to say about it. i did find this link though on soldering alu http://www.ganoksin.com/orchid/archi...8/msg00348.htm __________________ Asus A7V266, AMD1600xp 1x 256ddr 2100 Crucial radeon 8500 64mb, Ati TV-Wonder PCI Maxtor Diamond Max Plus 9 7200rpm ata133 & 60 MAXTOR ata100@5400rpm 6xdvd, TDK dvd+RW SoundBlaster 5.1 w/ logitech Xtrusio DSR100 speakers Case: Enlight 7237 Last edited by lukasz70; 01-18-2003 at 11:29 AM.*

01-18-2003, 02:18 PM	#12
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	It's not impossible to solder aluminium, but it is difficult: First, it melts extremely easily, and as the link states, form an oxide. Much practice required. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

01-18-2003, 08:17 PM	#13
lukasz70 Cooling Savant Join Date: Nov 2002 Location: Ontario. Canada Posts: 159	k, asked my dad again about alu, apperantly you can weld alu only to alu using MIG and TIG, but you cant weld other metals to it unless its plated. as for soldering, its like the link says "there HAVE been several solder formulations developed for aluminum, each with it's own specific type of flux". but I doubt that these are available at your local hardware store, __________________ Asus A7V266, AMD1600xp 1x 256ddr 2100 Crucial radeon 8500 64mb, Ati TV-Wonder PCI Maxtor Diamond Max Plus 9 7200rpm ata133 & 60 MAXTOR ata100@5400rpm 6xdvd, TDK dvd+RW SoundBlaster 5.1 w/ logitech Xtrusio DSR100 speakers Case: Enlight 7237

10-05-2002, 10:00 PM	#3
RoboTech Cooling Savant Join Date: Sep 2002 Location: Cincinnati, OH Posts: 229	I have been using a lot of AX-7s with great results. I have often wondered how Thermalright bonds the aluminum body to the copper base? I assume it is a thermal epoxy (sorta like AS epoxy?). I don't know of any solder/flux combo for Cu-AL??? Does anyone know for sure how Thermalright bonds the Al to Cu??? Thanks, RoboTech

12-10-2002, 11:54 AM	#5
Since87 Pro/Guru - Uber Mod Join Date: Sep 2002 Location: Indiana Posts: 834	This appears to be a very bad design. Due to the difference in the coefficients of thermal expansion for copper and aluminum. Repeated thermal cycling of the heatsink will rip the solder joint apart. The coefficients of thermal expansion are: Copper - 17ppm/K Aluminum - 25ppm/K Some more info here.

12-10-2002, 01:28 PM	#6
hara Cooling Savant Join Date: Oct 2002 Location: Malta, Mediterranean Posts: 662	can copper be fused to al?

12-20-2002, 09:47 PM	#8
RoboTech Cooling Savant Join Date: Sep 2002 Location: Cincinnati, OH Posts: 229	Someone told me recently that the aluminum body on the AX-7 is tin plated, which allows it to be soldered to the copper base. That sounds plausible... ??? and I've noticed the AX-7s do look like they have some sort of plating. Anyone else heard this?

01-19-2003, 09:09 PM	#14
jaydee Put up or Shut Up Join Date: Dec 2001 Location: Spokane WA Posts: 6,506	I have been a certified stick and wire feed welder for 7 years now. Been in fabrication and erection for 8. Sheet metal and heavy steel. Just in the last few months got transfered to the boss's other company to run the engraving shop. I have soldered AL to AL with just flux and solder from Home Depot. It is a royal pain but if you have patients and hit the heat levels at the right moment it can work but rarely done. It is just to much a pain in the ass. Also in reference to the pic I posted, if you can get the solder to actually stick to the al your set. I did that and then solder a little onto the copper fitting and heated both peices up to where the solder was liquide and touched them together. It is a bitch to do. it took a couple hours but I was determined. Since swappedthat out for a read barb.

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