Something to think about, liquid metal compatibility with copper heat sinks

While those who are familiar with galinstan (liquid metal) type thermal compounds and how very bad it is to apply these to aluminum it is probably not thought of of how this works with copper.

Galinstan is an alloy of gallium, indium and tin that has a melting point of -19 C and a boiling point of 1300 C (no other metal has such a big difference between the melting and boiling point). This means that it remains a liquid at temperatures across what a CPU would see, unless you took your powered down laptop to Antarctica or Siberia and left it out in the cold where the galinstan would solidify and expand by about 3% (potentially tearing the heat sink off of the CPU if you did not make room for expansion).

Gallium loves to alloy with other metals; even with copper the metal ions will migrate in to the copper metal, gradually creating a copper-gallium alloy that is grey-silverish in color.

What makes this happen much faster is the electrochemical potential of the two metals. This is the same principle that makes an old fashioned lead-zinc battery function. Two metals in contact create an electrical potential and current will flow. One will oxidize (corrode) and the ions will move other to the other metal where there is a reduction (or plating) effect. Electrochemically speaking, the most negative metal will sacrifice itself by corroding away to build up a layer on top of the positive metal.

Electrochemically speaking, gallium has a potential of -0.53 volts and copper has a potential of +0.334 volts. The difference between the two metals is going to create a "battery" with a potential of 0.864 volts.

Gradually this battery will deplete; as the gallium migrates over to the copper. You may have heard some stories about how gallium "dries up" and evaporates. In many of those cases it is likely that it acted like a battery and migrated over to and became part of the copper heat sink.

If you take apart the heat sink from the CPU and clean it up you may find that the copper heat sink is colored a silverish-grey that resists efforts to even buff it off with a scrubbing pad. The stuff you can polish off is a corrosive residue of oxidized gallium and the stuff you cannot remove easily is now an alloy.

One good piece of news is that if this happens repeatedly the battery action will stop, as it is pretty inefficient to put gallium and have it migrate over to a gallium-copper alloy.

There might be a few things that are not so good news. It is possible that the gallium-copper alloy is much less a thermal conductor than pure copper. It is also possible that the alloy is not as structurally sound as pure copper or becomes brittle (gallium is pretty brittle when it is solidified). You may not even notice the first instance of less thermal conductivity unless you were in a laboratory setting and counting calories (thermal) and heat transfer characteristics, the actual difference may only be 1-2 C in a computer and that can get lost in all of the other variables of how computer CPU's cool, loading, power, air temperature, dirt on the fins or fan inefficiencies.

The second thing regarding brittleness might only be a concern on a vapor-phase heat sink where the metal is very thin. Again, this is not proven by any particular instance but there is always the potential of the vapor phase heat sink of fracturing and letting out the magic cooling juice, right on to the CPU. (do not panic over this statement, I am not backing it up with any examples but maybe heat sink manufacturers should look in to it).

If you look at the IHS (integrated heat spreader) on top of a CPU it is made of nickel plated copper. If you ask the question "why did they put nickel on top of copper? copper is so much better of a heat sink material) it may be due to the corrosion vulnerability of copper.

Actually having the IHS plated with nickel is a good thing, it has a galvanic potential of -0.3 volts, much closer to liquid metal so the corrosion between the CPU IHS and the liquid metal is almost nil.

What might be an idea is to electroplate the contact area on the heat sink with nickel (nickel can electroplate directly to copper) and it would be over an area about the size of a postage stamp. In manufacturing that plating takes about five minutes but there is quite a bit of set-up to keep the nickel just where you want it and not over the entire heat sink.

You "could" electroplate nickel at home but it is a fairly toxic process and generates hazardous waste.

Again, maybe heat sink manufacturers can consider some sort of plating process.

Another alternative is a barrier that prevents electrical connection (that allows the battery action of galvanic corrosion from happening) but still has very high thermal conductivity. We have had this with regular ceramic, alumina (and even silver based) thermal pastes. No matter that the word aluminum or silver is in the name, most are pretty horrible electrical conductors.

This problem is pretty unique to just the liquid metal TIM (thermal interface materials) crowd but it is something that we should be aware of.

(BTW, I nickel plate and then silver plate my heat sinks but I have the experience from doing this with jewelry. It is an expensive and potentially toxic thing to get in to just for a heat sink).

 

First off, very informative post.

Question:

Have you had any experience with liquid metal paste actually staining a silicon die?

I applied some Thermal Grizzly Conductonaut on my 920xm. After a couple of months, temps started shooting up dramatically with low CPU usage. I removed the heatsink and found the paste had hardened almost completely, except for a couple of tiny spherical clumps of paste here and there. I noticed the stain left behind on the copper heatsink (which I had to sand down with 800 grit sandpaper to remove) but I also noticed that it left a film on the silicon die as well. I tried removing it with different solvents (even acetone) but nothing removed it. I ended up using a scotch-brite pad to get it off and that obviously that left some fine scratches on the die but it doesn't seem to affect performance.

I am now using Gelid GC Extreme which is a very good non-metal paste. I'm pretty hesitant about using the liquid metal stuff again because of the staining, but mostly because it hardened so soon. The temp drops were initially phenomenal however and really helped me with overclocking.

 

I do not know if it is necessarily bad for the stain to exist or even if there is a migration of some of the metallic elements in to either the IHD, heat sink or the ceramic at the top of the CPU die. It is just an observation and there has been some research done in to how gallium (and its alloys like galistan) interact with copper in much more critical applications than a computer heat-sink. We know that aluminum heat sinks would be a awful thing.

( gallium and aluminum reaction: )

( research paper on gallium and galinstan alloy compatibilities with copper: (you will really need to be a nerd to read this) http://www.dtic.mil/dtic/tr/fulltext/u2/a201304.pdf )

Copper and nickel will stain and have some minor pitting, leaving behind a "sludge" (their words in the research paper) but if you replenish the LM the generation of sludge slows down; they did not note a complete breakdown of copper. Additional investigations were in to the use of galinstan as an electrical conductor in homopolar motors (look it up, quite cool) and as a thermal conductor in future fusion reactors.

 

Interesting posts. I have been using CLU for about 18 months now, before that Gelid GC Extreme.

My latest application lasted 1 yr and I finally started noticing that temps were starting to creep up again. After another repast, it seems as good as I can remember even with the copper staining. If it does indeed cause issues with Copper, I haven't run into it yet.

If it does ever cause issues, I will share on the forum.

 

@Tishers - Thanks for the post. A question - any chance it happens at a certain temperature? I think that once the CPU passes ~80ºC (maybe a bit more) it's a steep downhill from there, it degrades pretty fast. This is my observation at least.

 

Most assuredly any sort of chemical reaction will happen quicker as temperatures increase. In the reading I have done on the topic the threshold seems to be up around 300 C before things get really out of hand.

That is one of the reasons on why I brought up the galvanic reaction between dissimilar metals. If two different metals are in contact and you create another electrical path around them you get current flow. It is exactly the same principles that make up a "battery". One will sacrifice itself and corrode away, while the other metal accumulates a crust of oxides and electrolytes.

If there is a galvanic reaction you can easily check it. Take a piece of Nickel (even a real us Nickel), a dab of TIM (galinstan) and a piece of copper (a penny, but that is only a copper coating). If you have a voltmeter you can measure the electrical potential from the penny to the nickel, with the galinstan acting as a metal-electrolyte in between. The value will be in the fraction of a volt.

Now imagine that as your computer heat sink on a CPU. The heat sink may be electrically isolated (by a plastic bracket) or electrically "bonded" with screws to metal that are running in to the motherboard where they are part of the ground-plane (definitely if they are going in to a steel chassis). With the electrically bonded connection there will be current flow, just like discharging a battery.

The old zinc-carbon batteries basically corroded away the cathode that is the outer case of zinc (the negative most connection) to "protect" the carbon anode in the battery (the positive most connection). That is why dead batteries are never a good thing to leave in an item, they corrode away and ruin the item. But you also know that even charged batteries can corrode away all by themselves over time (albeit much more slowly). There are enough chemical impurities in the battery that it has its own self-leakage and even things like how much a metal is tempered (like a die extruded heat sink is harder and softer in some areas) will cause small circulating currents that cause localized pitting.

It has probably been entirely overlooked by many in the overclocking/ liquid metal TIM crowd but corrosion is a very real concern. You can bet that Intel has thought of it and it would not be surprising at all to find that they have researched the long term implications of liquid metals CPU package.

I am aware of it because of one of the many hats I have worn in my career was as a corrosion engineer for an oil company. Dissimilar metals were always a concern and if we made a mistake in protecting and bonding it could result in a spill or an explosion.

 

That's pretty wild, and it makes perfect chemical sense. I say I haven't had issue with CLU on my M18x R2 for the past 2 years, but the number of extended heat/cool cycles it has been exposed to is very, very minimal, so to say liquid metal does have a "timer" in a sense for how long the system has for the gallium to alloy itself to the copper. Pretty amazing

can be mitigated by adding more liquid ultra/conductonaut as you said, but it would reduce thermal conductivity as it is transferring to the gallium-copper alloy instead of pure copper instead.

mind blown. I wonder if CL or ThermalGrizzly know of this process..

 

@Raidriar - Have you ever passed 80~85ºC? I think that's what "activates" it. As long as you keep under 80, I think everything is good (for prolonged use, as I said, once certain temp is passed it degrades in a matter of weeks, not to say days).

 

oh yes, things get very hot at 4.4ghz full load 4 core. usually tops out around 84 degrees

 

I've seen others talk about this ( @Mr. Fox - I believe), and most posts say that the staining is normal, and can be left behind as it won't affect thermal transfer into the heat sink.

From the posts I've seen about this, if there is a poor fit between the heat sink and target component, a small amount of air may be getting to the Liquid Metal causing it to harden up over time. Some have suggested entirely surrounding the liquid metal with something like GC Extreme in order to prevent any extra air to the LM in cases like this.

 

I can attest, that my liquid metal TIM has never dried UNLESS there was a gap that allowed air to get into the system, which dried it out into a fine metallic dust...not good. So long as the heatsink fitment is airtight, I have not had any drying out of either CLU or conductonaut

FWIW, my M15x has conductonaut and that is routinely up in the 80-90 degree range under load (small fans, small heatsink, hot chip = thermal hell)

Has not dried up yet. And keeps cool when it is not under high load or high clocks.

 

I had to add more LM within a month of initial application as it would 'dry' where heat sink contact was not perfect. Even then, where almost half of one GPU had that 'dry' look on the surface, temps were not affected by more than a few C. Only the first time where I think it lost almost complete contact (which prompted me to bend the heatsink to get better contact) did temps on my slave GPU start getting higher then shoot up to thermal throttle range under load then 80C at idle; this happened over the course of a few hours.

I've not yet cleaned it off though, Conductonaut is not like paste it's easy to add more of. It has a surface tension that keeps it together. I rework it all over the die/hs area then add a tiny bit more and it disperses nicely.

I have Conductonaut on 6700K IHS (soon to be under it too- delid tool in transit) and on both 980M dies. On the 980M's temps are great. I don't think I've ever seen them over 80C even on a +225MHz @ 1.087V which is as far as I've taken them so far (still have some voltage and temp headroom)

 

I have almost a kilogram of the material stored in plastic bottles, as long as it remains away from air it does not change state. It will remain liquid, shiny and easy to apply.

I had left some in a ceramic crucible that is about the size of a shot glass (maybe 20-30 g of material) and I forgot about it for a few months. The stain did penetrate down in to the ceramic, I did not note an appreciable difference in the quantity of materials but it did develop an oxide coating over the gob of liquid metal. I am sure that if the environment was a bit more hostile (wet, hot or in contact with metals that it could alloy with in to a surface amalgam) then the apparent quantity would decrease.

The real test would be to take a precisely measured quantity of material with a coupon of copper and another of nickel and to make a sandwich and to find the weight of the combination of the three items. Then to expose the sandwich to heat, humidity, air-flow, slightly corrosive atmosphere for several days or weeks (heat will accelerate the process, there is a mathematical model known as the arrhenius equation that can correlate accelerated aging to real world chemical processes). Then to weigh the entire sandwich and determine if the material really did "evaporate" or if it just migrated in to the base metals on either side of the sandwich.

I might even be able to take it a step further and to squeegee off the LM and to weigh what remains to find how much migrated deeply and is more than just a surface stain.

P.S. Any university students who might want to do that as a lab project? You could probably write a really cool paper on it. If you are studying materials science or even electrical engineering it would be a useful project that would benefit the industry. (A high school student doing such a project would really draw the attention of university recruiters)

 

That is correct. Staining is very normal and in fact, I've found from numerous of my own controlled tests that a stained copper heat plate yields slightly better results with thermal conductivity.

I work with this stuff daily and all my laptops / computers are LM'ed. Even my MBP and XPS.

The most important thing is to make sure that the tolerance levels are on point. I've made many posts about the experiences that people have with LM in general.

The OP did a great job with the scientific aspect of explaining the properties of the elements and that is on par in validating the contents of my replies to many of the members on here.

Regarding the surrounding of the dies with using thermal paste, I personally wouldn't recommend that. In theory it sounds good, but trust me when I say that it is more important to address the tolerance levels and to apply the correct amount of LM over anything else.

.

 

What iunlock is trying to say is, you should NOT use a crutch to compensate for lazy work. His idea is that using a foam barrier when you have a heatsink that is so badly fitting that there are caps, to try to stop LM runoff, means you should NOT be using LM in the first place. You should either fix the deformed heatsink or pad layout, or use IC7 diamond. You also should not be using foam or kapton tape or other things to compensate for your mistakes of putting too much LM on in the first place.

What you should be doing is using the foam barrier as FREE INSURANCE after you have applied PROPER amounts of LM on a PROPERLY balanced properly secured heatsink, to prevent any LM from running off when the laptop is banged around in a backpack or other stuff like an airplane. Then that's a wise decision to make because you're using it as free insurance (the foam dam method), NOT as a crutch for laziness.

BTW the foam dam does NOT replace nail polish or super 33+ or Kapton tape over the SMD's !!! It's to be used only to stop LM random conductive balls of runoff from getting on the PCB!

 

So question: if Nickel electrode potential is -0.24v and cooper +0.34v; then the battery effect also happens between IHS and heatsink?

For a Nickel plated IHS what is the thermal conductivity?
Galllium diffused layer on cooper has comparable thermal conductivity to the previous nickel plating?

If most of these effects are true to nickel, maybe pre-apply LM to heatsink then heat it up (+300c) to speed the diffusion process; Then the long term issue is reduced somewhat???

Thanks for any responses

 

for those who wondered what would happen if you ignore the safety warning of liquid metal.

 

Indeed Liquid Metal will corrode aluminum in minutes. Great that my heatsink is copper.

 

Liquid Metal Pro destroyed my stock Dell Heatsink
sirgallium
Published on Sep 6, 2017
Liquid Metal Pro was a revolution in thermal compound when it debuted a little while ago. People on [H]ard|OCP say to get some and "claim your 15 degree drop."

It's so effective that you get a 15 degree cooler CPU just by using this compound alone which is insanely impressive, people pay hundreds of dollars for water cooling setups to get cooling drops like that and this compound is only about 12 dollars.

It does say on the package some kind of warning about aluminum, but most heatsinks *are* aluminum. I thought the warning was just that it doesn't spread easily on aluminum, it pools up on it and doesn't like to stick to it as you can see in my other videos where I installed it on my main PC.

My main PC also has an aluminum heatsink but it didn't destroy that one. So why did it destroy this one? Was it more porous? A lower quality aluminum perhaps? I don't know.


Edit: Forgot, there is already a thread about LM / Copper interaction here on NBR

Something to think about, liquid metal compatibility with copper heat sinks
http://forum.notebookreview.com/thr...-compatibility-with-copper-heat-sinks.800890/

 

Plenty of warnings to not use LM on Aluminum heatsinks.....old news....but good to remind new members. Conductonaut comes with a warning in the package.
Somehow the OP in his supposed extensive testing is the only one that doesn't manage to get better temps with LM over non conductive paste......hummmm. His tests, in another thread, claims that LM gets higher temps than the non conductive pastes he cites in that thread, which goes against the experiences of hundreds of users in this forum and around the globe. That being said, yes do not use LM on aluminum heatsink, it will corrode in minutes.

 

It's variable, depending on the application, the environment applied, and the skill / experience of the applicator.

There are some situations where only a few degree's difference show up, but more typically 10c lower. Non-conductive pastes are good to use to avoid the dangers of LM killing the laptop.

The LM dead laptop thing isn't spoken of much, and you really have to pay attention to find the few people that take the time to come back and post the failure - usually they are looking for help solving why their laptop is dead. It happens enough that it should also be mentioned, you could ruin your entire laptop - a total loss of CPU or motherboard, or whatever the LM rolls onto.

Then there is the long term effects, again depends on the materials involved, the environment, and the application / applicator.

DANGER! Coollaboratory Liquid Ultra - big problems after just one year
Ultimate DIY
Published on Jan 30, 2017
This was the second CPU with Liquid Ultra dried up on it after just one year. The first CPU probably died because of overheating. The one in this video survived because I realized what is happening.


sheer64 1 day ago
"Some of the stupid comments on here when this poor bloke is sharing an issue with this crap product. Well done."

Ultimate DIY 18 hours ago
"Thank you! People just like to think they are always right and others are wrong, even if evidence is shown."

Reports of this happening on desktops and laptops, I'd think more often on laptops due to the flexible cooling components.

Edit: Forgot, there is already a thread about LM / Copper interaction here on NBR

Something to think about, liquid metal compatibility with copper heat sinks
http://forum.notebookreview.com/thr...-compatibility-with-copper-heat-sinks.800890/

 

Ockham's razor, simplest explanation of why you don't hear more reports of Liquid Metal killing things is because... its not killing more things?

It's tricky to work with but it's up to the individual whether the risk is worth the reward.

It's not like standard pastes never go bad and dry up, pump out, get applied badly, have air bubbles or uncovered hot spots, get smothered all over nearby components (some are conductive), etc...

You can in some instances buy systems with LM applied during system build and covered under reseller warranty, they wouldn't expose themselves to that risk if they hadn't extensively tested it with their particular method. In hindsight it's safer to do now than it was >18months ago the first time I tried it, I had no idea about protection at all, just naked on CPU and GPU dies with no foam or tape or liquid tape/nail polish (not even on the caps around the GPU core).

 

Sure they are risks, and it is documented well in this forum, just the OP tests are questionable as well as many things he claims in various threads. Not only questionable, but flat out wrong, just trying to create an endless discussion on how right he is, and how nobody else's experiences are true/truthfull or relevant. LM performs better in most situations when correctly applied than non conductive paste. Period. Yes they are risks and proper care to be taken and anybody attempting to use it should research extensively before applying and decide if it is worth it, over a non conductive paste. Or like you say, just undervolt, if it doesn't reduce temps enough to not thermal throttle, then just return it or RMA.

 

No, I think it's mostly embarrassment at screwing up. Everyone does it of course at some point or another, screws up. But newbies often haven't failed enough to know it's ok and better in fact to fully disclose.

I think there are far more unreported failures of owner DIY work of many kinds than reported ones.

I also think it's far more important to mention the pitfalls than the benefits, as there are plenty of LM proponents here pushing it - selling it as the *only* solution, and not enough people posting LM warnings, suggesting non-conductive alternatives, and better yet - recommending starting with free non-invasive software tuning solutions before tearing apart your brand new laptop.

Edit: Forgot, there is already a thread about LM / Copper interaction here on NBR

Something to think about, liquid metal compatibility with copper heat sinks
http://forum.notebookreview.com/thr...-compatibility-with-copper-heat-sinks.800890/

 

Very true, it was simpler times back then. When I first started using Liquid Ultra in 2014, almost nobody ever talked about protection, so I just went in raw. Back then LM was a lot more niche, most of the people using it were enthusiasts and understood the risks and pros/cons. Since LM started becoming a lot more popular and mainstream recently, I feel like there has been a jump in fearmongering, FUD, and misinformation surrounding it as well.

 

Yup, LM failures are inconvenient and easily explained away by the LM proponents, unless you are stuck with a dead laptop / desktop due to LM screwing it up.

There are lots of interesting points made in that video comment section, including some poor incensed guy that lives where CLU headquarters is located.

 

Thanks for posting the helpful video and discussion on LM application.

Liquid Metal on naked GPU die after 3 months - bad heat sink fit!!!
bennyg
Published on Mar 20, 2017
Learn from my experience with liquid metal and hopefully this can help you troubleshoot your setup, avoid the problems I have here, and avoid the even worse ones where your hardware is KILLED by liquid metal squirting everywhere.

Spoiler: Details...

Clevo make some heatsinks better than others, and heatpipes are very easy to bend out of shape. Mine weren't good. This video is part way through a long process of perfecting the fit.

As a result you can see here what you SHOULDN'T SEE from a good application of liquid metal - partly dried up liquid, and big blotches.

The yellow tape is there as a precaution against spills, because I knew the fit wasn't good.

Note: this is a revised description because loads of commenters below seemed not to get the point of this video. It's not a how-to on doing it perfectly.

Original application slightly over 3 months ago.

Approx 1.5 months ago, after being the same as the master GPU's temp, the slave's temp started rising - over the course of a day the delta to master GPU temp got bigger eventually it was idling at 80C and thermal throttling in seconds under any load. So I took the heatsink off, the liquid metal had dried up completely. So I attempted to realign it and added more LM.

This is what I found when I pulled the heatsinks off to check a couple of months later... the liquid was still liquid except where, due to not enough liquid metal and an imperfect heatsink fit, there was insufficient contact, and it looked dry. Immediately prior to this video the slave GPU temp was still only a couple degrees C hotter than the master after the last application.

After this video 1.5 months ago, I further realigned the heatsink, added LM to the slave GPU and carefully replaced the pads with new pads of appropriate thickness. When I pulled them again yesterday, both looked exactly like the left GPU on this video - complete die contact. The 75C maximum even when overclocked 30% (1350mhz core) says it was still cooling really well.

Hopefully this video helps you understand liquid metal a bit better so you can use the appropriate amount because the thermal performance is unreal!

If you can't fix a big gap you may be better off using a paste instead. The liquid metal can run if there's too big a gap to fill and it will do Bad Things if it escapes due to its conductive nature.

Edit: Forgot, there is already a thread about LM / Copper interaction here on NBR

Something to think about, liquid metal compatibility with copper heat sinks
http://forum.notebookreview.com/thr...-compatibility-with-copper-heat-sinks.800890/

 

Plus you guys keep talking about "aluminum" heatsinks.
Most heatsinks are basically primarily aluminum, with few exceptions, mainly due to weight and heat retention (aluminum releases heat faster than copper, while copper transfers heat faster from the source but also retains it more as well (fins). Ignoring the heatpipes, we need to focus on the heat plate itself.
A good example of this is how well or poorly the old TRUE Copper heatsink worked (far too heavy, caused motherboard flexing, didn't release heat fast enough).
It's the HEATPLATE that you need to be concerned about.
Copper heatplates are safe.
Aluminum heatplates are NOT safe.
Nickel plated heatplates are safe (either nickel plated copper or nickel plated aluminum).

Some clevos have the entire chamber and fins made of copper. You need powerful fans to dissipate heat from copper fins.

 

So, wouldn't that in itself constitute the plating one actually needs on a copper cold plate to stop the battery reaction from happening any further?

Maybe the key with LM is to replace often, say each 3 months for the first year.

BTW! your initial post was an absolute gem.

 

There are reports of LM on copper causing staining from corrosion, gallium absorption into copper leaving hard residue's - solid at room temperature elements of the LM, reducing thermal conductivity in the absorbed gallium / copper bonded areas of heatplate material under the die.

That video I posted has many copper experiences with LM related:
Comments

Ultimate DIY 1 year ago
"+K3YSP3R so basically it should not be used on laptops? If this is true, maybe they should write this somewhere on the product or their web page, so people can avoid future problems."

deviceundertest 1 year ago
"are you sure it was Ultra not Pro? they advertise MetalPad to use with laptops"

Ultimate DIY 1 year ago
"+deviceundertest it was the Ultra for sure."

Overloke 3 months ago
"It is not meant to dry this much, and anyway, this isn't normal drying. This is metallic corrosion caused by the Gallium in the liquid metal reacting with the copper of the heatsink."

Gosu 3 months ago
"Well... he actually linked papers about this and you can clearly read there: "It’s known that liquid gallium reacts with copper (Ga + Cu → CuGa2), and the reaction ceases when gallium is consumed completely""
http://www.ipme.ru/e-journals/RAMS/no_81808/grigoryeva.pdf

"1. INTRODUCTION Solid metallic alloys interact with liquid metals in various fields of engineering, such as soldering, sintering involving a liquid phase, and metallurgical processes. These processes have been mainly studied for binary systems. In this work, we studied in situ the interaction between binary mechanochemically synthesized solid solutions and binary gallium eutectics by X-ray diffraction with the use of synchrotron radiation to find the phase formation sequence for the elements released.

It’s known that liquid gallium reacts with copper (Ga + Cu → CuGa2 ), and the reaction ceases when gallium is consumed completely [1-4].

If a gallium eutectic is used as the liquid metallic phase, the transfer of gallium from the eutectic to the forming intermetallic phase is accompanied by the liberation of the other component of the eutectic. Also, if the solid phase is an alloy rather than a pure metal, one component of the alloy reacts with gallium, while the other is liberated. As a result, there are free metals from the eutectic and alloy, which may also react to form an inter-metallic compound."

Pinned by Ultimate DIY
bobsagget823 9 months ago
"Leaving this as a top level comment so more people can see it:
I did more reading about this stuff since I'm interested in using LM for my own laptop, and it seems corrosion is not out of the norm.

Typically when LM is used under the IHS of a desktop CPU (often necessary for intel chips since they bond the IHS to silicon with toothpaste instead of solder) the results are pretty good even after a year.

The IHS (which is made out of copper, then nickel plated) does get stained by the LM but nowhere near what happened to you. This is because your contact (in a laptop) is silicon die <-> LM <-> copper heatsink. In the desktop scenario, LM is often applied underneath the IHS so the contact is silicon die <-> LM <-> nickel plating <-> copper.

To be even more clear, the key differences in your application of LM is that:

1. Your application was silicon-copper instead of being silicon-nickel as you would find in the 'delidding' of a desktop CPU

2. Your application was not insulated against air (read: oxygen)

1 is important because the electrode potential of gallium is -0.53V, nickel -0.24V, and copper +0.34V. Obviously, all liquid metals are made out of gallium (because Ga is liquid at room temp, and is also nontoxic unlike mercury) plus small percentages of other metals to reduce the melting point.

When gallium is in contact with pure copper, the differences in electrode potential favors the gallium and copper to alloy, which will eventually consume the gallium completely[1] (Ga + Cu → CuGa2 [67%] + Cu3Ga [11%], and both products are stable until 175C)[1][2].

The liquid metal will literally into the copper until the gallium is gone, which causes the copper to turn silver-ish.

The non-gallium components (indium, tin) of the liquid metal[3], which are solid at room temperature, get left behind - and that stuff is hardened deposit that you were trying to scrub off the heatsink.

Note that at higher temperatures, the reaction between gallium and the copper heatsink only gets faster.

2 is important because the gallium based LM components can and do oxidize.

This is the reason why people generally recommend sealing your contact as much as possible. With a desktop chip under an IHS that's already halfway taken care of by the IHS itself, so if you've never seen a liquid metal tutorial for a laptop you might have not even known that sealing the LM was important.

I'm not making this stuff up, gallium begins to oxidize at 25C and fully oxidizes at 75C[2] (Ga2O3, mass fraction 0.12) which is a totally achievable temperature range. This is not even considering the fact that the other components on the LM can oxidize, and they likely will.

Other interesting things to note:

1. The thermal conductivity of CuGa2 (the principal alloy of gallium and copper) at 20C is 98 W/(m⋅K). Copper's thermal conductivity at 20C is 400 W/(m⋅K).

2. We have no idea what exactly is in LM, the formulations are proprietary - but it's been said that the consistencies of Coolaboratory CLU & grizzly conductonaut are not the same so clearly whatever is in this stuff varies and lead to different results.

3. Simply buffing the residue off the copper heatsink and reapplying the LM might be OK. The GaCu alloy is obviously not as good of a heat conductor as pure copper but it's not clear how deep the gallium will attack. If eventually you keep reapplying LM and the gallium can't penetrate its own pitting then it's effectively self-limiting and you end up with a 'stable' LM application.

These papers are interesting if you want to learn more about the process:
1. http://www.ipme.ru/e-journals/RAMS/no_81808/grigoryeva.pdf
2. https://sci-hub.ac/https://www.scientific.net/DDF.326-328.227
3. http://forum.notebookreview.com/thr...-compatibility-with-copper-heat-sinks.800890/

TL;DR
Liquid metal pastes react with copper heatsinks (aggravated by oxidation and higher temperatures) until the gallium in the paste is totally absorbed by the copper heatsink and you end up in thermal runaway. The damage to the copper is permanent, but if you keep reapplying the LM whenever this happens you may end up with a stable LM application. LM is much more stable when used under the heatspreader of a desktop CPU, since the heatspreader is nickle-plated and way less reactive to the LM."

Ultimate DIY 9 months ago
"+bobsagget823 thank you for this explanation! I will pin it as the first comment so more people understand what happened."

Romick Vieira 3 months ago
"bobsagget823 ok, so, basically, only good for delided cpus under the lip. Used below the copper heatsink it reacts, well its not worth the risk, not gonna use it. ill use kryonaut then"

aciemiller 2 months ago
"YOU ARE MY HERO BOBSAGGET823!!!

I live in the same town where Coollaboratory lives and you CAN'T buy from them directly 'coz they are frauds, liars

....so sad that so many fools just can't see that the CLU is DRY and not WET on his CPU maybe they are just plain stupid or get even paid to talk **** like this.

btw. I'm a hardware MANIAC and have changed the TIM countless times on a naked 3570K with Coolermaster Master Gel and Phobya HeGrease Extreme.

You people get all fooled by so many liars and you even like it to be stupid enough to buy their ****.

Thanks a bunch for your comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"

Edit: Forgot, there is already a thread about LM / Copper interaction here on NBR

Something to think about, liquid metal compatibility with copper heat sinks
http://forum.notebookreview.com/thr...-compatibility-with-copper-heat-sinks.800890/

Here's another example of absorption of Gallium into Copper after 5 months, requiring re-pasting to re-apply over absorbed area, he speculates that the converted gallium / copper heatplate material won't absorb more gallium so it should stabilize and slow down the requirement to repaste to longer than 5-6 months between re-applications of LM to the CPU / GPU.

ASUS ROG - Liquid Metal 5 Months Later! Followup
Mr. T's Tips
Published on Dec 27, 2017
5 Months after the initial Thermal Grizzly Conductonaut liquid metal thermal paste application to the ASUS Republic of Gamers GL702VS, I tear apart the same laptop to check how the seating held up and if there was any "damage". Everything looks stellar, and with the thermal bond stronger than ever, my temperatures are now lower than ever once I applied another bit of Thermal Grizzly Conductonaut to the dies!


Thomas Luna 1 week ago
"How often do you recommend repasting the laptop with liquid metal? Thanks for the video btw."

Mr. T's Tips 1 week ago
"I might recommend doing a repaste after the first 6 months, and then 12 months from there."

Original re-pasting video:

Laptop Liquid Metal Re Paste - Asus ROG GL702VS - and 20-30C Difference! - HEAT FIX
Mr. T's Tips
Published on Jul 19, 2017


Edit: Forgot, there is already a thread about LM / Copper interaction here on NBR

Something to think about, liquid metal compatibility with copper heat sinks
http://forum.notebookreview.com/thr...-compatibility-with-copper-heat-sinks.800890/

THERMAL GRIZZLY KRYONAUT, THERMAL PASTE - REVIEW
DF Gaming 90
Published on Dec 14, 2017
This is a product review and application guide for Thermal Grizzly's Kryonaut thermal paste which I have just discovered and it's a game changer when it comes to temperatures and overclocking.
I highly rate this bit of kit and coming in at £15.99 at the time of making I'd say it's well worth the investment.
CPU - Intel 6700K
MB - MSI M5 Z170
Skip to: 2.54 mins application guide
Link: https://www.amazon.co.uk/Thermal-Grizzly-Kryonaut-thermal-paste/dp/B00ZJSF5LM


DF Gaming 90 2 months ago
"I applied this back in September 2017 and I have maybe had as 1/2 degree increase when rendering. Nothing noticeable, gaming loads stay in the mid 50,s at 1.31 volts. Impressed me, after 7 month I thought there would have been some degradation but it's sweet."

Acer Predator G5-793 Tear Down, Kryonaut and Reassemble!
Bob Of All Trades
Published on Mar 14, 2018
Follow along as we replace the 14 month old stock chewing gum paste with Thermal Grizzly Kryonaut.
Stock peak hit 97c with extreme variance between cores.
Kryonaut dropped max CPU temp to mid 70c with 2c variance between cores of 19c.


Superjay2009 1 month ago
"Great Job used same paste on My Alienware 17 R3 with excellent results low 30c and High 68C"

Bob Of All Trades 3 months ago (edited)
EDIT: I finally after cooking this in a small office with the back of it within inches of a wall and small ledge near the tip on the monitor (dry erase board marker/eraser holder) I was able to hit 74c after an irresponsible 2+ hour gaming session. Still at stock voltage. Temps were: 74c 74c 73c 70c GPU hit 68c Ambient temp 70F

Sheesh, why don't these guys undervolt? It's so easy and drops 100% load temps by another 10c - added on to re-paste that's great.

And, if he was getting 97c on stock paste after 14 months without undervolt, he could have easily undervolted and dropped that down to 87c and completely skipped the re-paste.

 

Forgot this thread was here... started additional copper / LM interaction posts into this newer thread:

This is what happens when you apply LM to aluminium heatsink
http://forum.notebookreview.com/thr...m-to-aluminium-heatsink.820440/#post-10753996

 

You could replace the nickel plated IHS for a full copper one if you wanted. Is there a need to remove the heatsink that much though aside from cleaning/removing dust?

 

So. I checked my LM application after only two months.

Between a Ryzen 1800x and an asetek Gen 4 pump (copper plate)

The CPU IHS was literally glued to the plate, I needed to pull the CPU out of the socket, thankfully the puppy still works fine.

Tried with car polish and while it helped it was too darn slow and I switched to sand level both surfaces until I got rid of the residues on both surfaces.

Not worth the effort IMHO, not if you need to pull the CPU out of the socket like that. The temps however were fantastic all this time, I could of leaved it alone but prefer to be safe than sorry.

So, no I wouldn't advice to use LM, period. Even the IHS got compromised.

 

You're not supposed to use Liquid Metal on desktop CPU's between CPU and heatsink. It's really not worth it at all.
That is usually done on laptops because laptops are already bare die, and need all the help they can get, with their weak heatsinks.

You're supposed to use it on DELIDS. E.g. removing the Intel pigeon poop *under* the IHS. That is 100% safe and has been time tested by the very best overclockers in the world. The only time liquid metal should NOT be used on delids is under subzero. And you wouldn't want to anyway, since the power of LN2 > anything else--just use the basic pigeon poop.

For IHS to heatsink attachments, just use Kryonaut. If Kryonaut has pump-out issues on your system, use Coolermaster Gel Maker Nano.

Ryzens don't need to be de-lidded.

 

Yeah, I came to the same conclusion too. Only good on delidded chips.

Right after checking my system and fixing the mess I ordered some Kryonaut.

 

Pump-out issues?

 

Paste dries out with repeated heat/drying stress sessions (thermal stresses), especially on uneven heatsinks (this is very common on laptops). The performance is excellent but the durability is quite low. The heatsink must have high static pressure and must not have air gaps or convex/concave fits that will cause the paste to dry out in areas.

 

There's not much point to that, the ihs is already copper with nickel plating, but Ihs is only a thing with the few LGA (desktop) socket CPU laptops, notebook cpus are bare die even in the ye olde before times of the PGA mobile socket

Flatness is more the issue IMO you can see where this 6700k ihs was higher on the edges where the nickel wore off first then with a few more mins effort was flat (ish, that shot is what it looked like after the 240 grit sandpaper before finishing with 1200grit)





Liquid Metal alloying with copper is a surface reaction only, it is very quick to sand off, I reckon the layer depth would be in the tens of microns. If you're reapplying liquid metal again it's actually a fairly pointless thing to do.

I have noticed that reusing liquid metal many times leads to "grit" building up, this must be the non Gallium constituents coming out of a eutectic state as the Gallium is consumed or the whole mix is oxidised. Oxidation is not a big issue really, if contact is good it is restricted to the edges. As I showed in my video hmscott posted above, if you have crappy gappy contact, air may dry out the mix and shrink the contact area leading to die hotspots. Galinstan actually almost instantly oxidises in contact with air, this is what gives it a surface tension and causes it to bead in its droplets, but once the surface layer is oxidised what is inside is insulated from air, like a water balloon.

I would advise any liquid metal application be checked within 3 months to see if its lost volume by gallium alloying into a copper heatsink or oxidation. Thereafter it can last a long time, I opened up a Clevo with copper heatsink after 15 months and it looked and performed the same as it was applied, but this was not an initial application (the heatsink had already absorbed what it would)

 

Sir, never sand of all Liquid metal with next re—application of Liquid metal. I know you know all this But many don’t know this. Sorry if this is is replicated.

 

To me, if the CPU solders itself to the cooler is not a good thing. Does anyone knows if reapplying without sanding the alloy completely prevents the CPU from sticking?

After sanding down my cold plate and CPU I think it would be pointless to re apply liquid metal. It will glue itself again. However I'm still considering it, I can pull it once more carefully (maybe even loosening the retention arm first) if I have proof that subsequent applications aren't gonna be a mess.

Is a bit frustrating for me at this point. Just applied some Kryonaut and gosh my temps are so bad (+10c), much worse than when I was using Noctua paste.

 

As said above sanding the stain - Cu-Ga alloy - is of negative effect if you're going to apply LM again. Certainly wipe off the used liquidy stuff (which will have lost some gallium) with isopropyl+paper towel and reapply fresh, this 2nd application will not lose anywhere near as much Ga into the heatsink as the 1st.

I find it's more like a suction effect than "gluing" (and certainly "soldering" is the wrong term to use). I find a slight twist of an unscrewed heatsink or lifting on an angle is usually enough to break the 'suction' between CPU and heatsink or IHS and heatsink and have them come apart.

I learned a minor lesson in the early days I pulled up too hard too quickly on the wrong end end of a P870DM GPU heatsink which preferred to slightly bend along the 20cm long heatpipes rather than detach from the 980M with the combined suction effect of grippy thermal pads and liquid metal on the die.

Something's seems not right with your paste application there or the delid has been affected, 10C is a huge difference in the wrong direction between a pretty good paste (NTH1) and a very good one (Kryo)


https://www.tomshardware.com/reviews/thermal-paste-comparison,5108-9.html

 

Maybe....I just got some NT-H1 and will replace the Kryonaut today and see what happens.

If the temps are bad then I might have to further polish the sanded surfaces. If nothing works then I'll go back to LM but next time I will not sand the GaCu alloy.

Thanks for the reply...I wish I knew this before even attempting LM....there is little info about the re application (youtube reviewers are for the most part sloppy with this thing), certainly this is the only thread I found with the precise information.

 

Kryonaut out, NT-H1 in.

Instantly a huge change:

CB15

Kryonaut = 81c

NT-H1 = 72c

See? that Kryonaut is crap, maybe only useful with a much greater pressure.

 

Was your Kryonaut hardened or fully liquid? (Kryonaut should have the same viscosity as Arctic MX-4).
There were several bad samples of the 1g tubes being almost dried out, which I never saw in the 5g tubes.
Either way, regardless of the heatsink, you should NEVER have initial temps of Kryonaut higher than NT-H1, ever, regardless of what you do. The problems only happen after a week or so and thermal stresses, never initially.

Your problem is very likely just a bad sample (I would bet $100 cold cash on that).
I've compared Kryonaut vs NT-H1 on three surfaces already on 3 different devices (laptops, desktops, video cards, etc) and each one had Kryonaut better. And reference AMD cards are not known for their mounting pressure (it's lower than laptops).

 

I don't know. But mine was white and liquid, way less viscous than NT H1 (still viscous, not entirely liquid)...while NT H1 creates a "suction" effect, Kryonaut didn't. And as I said the temps are noticeably better on NT H1.

Anyway, I placed a complaint on amazon and got my money back.

 

Fake paste.
Kryonaut is NOT white and liquid !
It's actually mostly grey, although NT-H1 is much darker. But not white.
You had counterfeit paste. Sorry man.

 

Haha, funny. It was sent to me directly from Amazon it wasn't even a middle man.

 

It's VERY important to get your terms and descriptions right so that other people are not misled by your posts.
Kyronaut is NOT a white paste. If anything it's at best a light grey / gray.
Here is what a white paste looks like. And I just now took this picture for you even though it was not convenient for me to do so.



Arctic Ceramique 1 is the the left. THAT is a white paste.
Kryonaut is in the middle. That's more like a buffed off grey.
NT-H1 is on the right.

You can't possibly still believe Kryonaut is white.....although NT-H1 is much darker (that I stand corrected on. I was possibly mixing up Gelid, Phobya Nanogrease Extreme and Coolermaster Gel Maker nano as well (I have all those pastes). I don't use NT-H1. Not a good paste (but better than MX-4).

 

It was pretty much the one on the left. White.

 

Uh oh! I took some pics. Seems like is the legit stuff fellas. Hmmm! maybe they made a counterfeit that looks like it?

Someone told me Kryonaut needs 2 weeks to burn in. Is that true? The bag says "No Cure"

Pictures here:

https://drive.google.com/open?id=1f2GD25mjTHrlkadtLBAAFAmvSjE-Biyz