Diamond Like Carbon

[strad]

Since many here keep up on such things I thought I would ask if anyone has information on DLC and it's use in reducing friction in racing applications.
In my café racer Triumph I used pistons from the Rand corporation that had Teflon impregnated not coating them, that made them harder than tool steel and slippery as wet ice on wet ice. From what I have read DLC is even better and would be a great addition to valves and pistons in a racing engine.

[Jolle]

It sounds cooler then it is. It been in use for decades now. Those black Showa Suzuki forks have a DLC coating instead of chrome

[strad]

Thanks Jolle. First I have heard about it and they were discussing coating valve stems etc.

[humble sabot]

It's been very common on f1 cam shafts as well.
The nicest thing about it is that it's harder than most low friction coatings, even Ti nitride. The hardness of the coating only gets you so far, the rest of the system has to be well engineered too.

[tok-tokkie]

I have used it on a pendulum clock I made. I was concerned about wear on the titanium lifting tabs on the pallets of the escape. That is horological speak for wear on the faces of the pawls of the ratchet assembly. There are 86 400 seconds per day. The clock is expected to last a century or two. The action is hardened gauge plate steel sliding against the titanium tab. All very small and lightly loaded. I decided to have them (there are 2 pallets so each is lifted every other second) DLC coated. Done by Wallworths in Cambridge, UK. Since there is a minimum charge based on weight I also had all the hardened silver steel pinion gears DLC coated because it would cost me nothing & give a fabulous low friction surface against the gold plated brass gear wheels. Again at the opposite extreme of your application. Slowest pinion turns 1 rev in 12 hours. Fastest is 1 rev in 7.5 or 8 minutes (not sure which, seconds to minutes is 7.5* 8 for 60:1 but I think it is the 8:1 pair as the final set). The action of the clock was improved (ie the second hand jumped quicker) and I could reduce the drive weight because of the reduced friction. However the loads are all so small that it was not dramatic & I can't quantify the reduction.

Wallworths offer several variations on the DLC process aimed at different end objectives. For example slight alloying to reduce the friction level even further.

I will be interested to hear how it goes. My thoughts are light steel pistons with DLC coating should be wonderful.

[Big Tea]

Is this of any interest?

[strad]

Thanks... One of the things I find interesting about DLC is the application to hip replacement parts since I have a few friends with hip replacements and they wear out. While I started out interested in automotive applications I have since found many interesting applications.
I find all this research in nano technologies fascinating.

[Big Tea]

Thanks... One of the things I find interesting about DLC is the application to hip replacement parts since I have a few friends with hip replacements and they wear out. While I started out interested in automotive applications I have since found many interesting applications.
I find all this research in nano technologies fascinating.

I know its not F1 related, and this is probably not the place to discuss it, but ...
As something so hard, slippery and 'thin' is available, would it not be a better method to just line the joint instead of hacking lumps out of people? Like, injecting a thin film between the moving surfaces, like a balljoint?

[strad]

I'm not sure you can apply it in a surgical setting. It is applied using chemical vapor deposition.
Also in reading I have found they are already using it in F1.
""DLC is also used in the engines of modern supersport motorcycles, Formula 1 racecars, NASCAR vehicles""
I'm way behind the curve.

[Andres125sx]

I find all this research in nano technologies fascinating.

Indeed.

When I hear about nanotech investigation, I always remind an article I read long time ago about building an elevator to the space with a module at the end wich would balance its own weight with centripetal force. When I read it it was just one of those articles about wonderful futuristic ideas wich are not possible yet, but wich should be with carbon nanotubes. Obviously when financially it is viable and we´re very far from that, but just the idea makes me dream

[Big Tea]

I find all this research in nano technologies fascinating.

Indeed.

When I hear about nanotech investigation, I always remind an article I read long time ago about building an elevator to the space with a module at the end wich would balance its own weight with centripetal force. When I read it it was just one of those articles about wonderful futuristic ideas wich are not possible yet, but wich should be with carbon nanotubes. Obviously when financially it is viable and we´re very far from that, but just the idea makes me dream

There is a guy on youtube called Isaac Arthur. His items seem to be what you like.
I have been sub'd to him for about 5 years. Start with his earliest as the latter ones are very sci-fi.

[Tommy Cookers]

Thanks... One of the things I find interesting about DLC is the application to hip replacement parts since I have a few friends with hip replacements and they wear out....

As something so hard, slippery and 'thin' is available, would it not be a better method to just line the joint instead of hacking lumps out of people? Like, injecting a thin film between the moving surfaces, like a balljoint?

afaik ....
joints are relined with hemisphericalish titanium/PTFE liners eg in young dogs and young people eg Andy Murray
refacing the bone as necessary for installation - young bone will then regrow and bond to the back of the titanium

old people can't be refaced as their bone won't regrow suitably
they need a replacement joint that has integral pegs - to be glued into counterbores in the bones (my words)

the peg-and-counterbore works fine eg in a knee joint - because the loads are endwise
but not in a hip joint - because there's lateral load which tends to spread the counterbore and walk around (my words)

these days there's no wear problem with replacement joints
but there's a problem with replacement hip joint loosening and pain - this has no remedy (my words)
ie worldwide 95% of non-hip replacements are good over at least 25 years - but only 54% of hip replacements
on average hip joints are replaced at a patient age of 68

my doctors get paid £200 to defer indefinitely hip joint replacement in those whose clinical condition justifies replacement
good old NHS !

[Big Tea]

Thanks... One of the things I find interesting about DLC is the application to hip replacement parts since I have a few friends with hip replacements and they wear out....

As something so hard, slippery and 'thin' is available, would it not be a better method to just line the joint instead of hacking lumps out of people? Like, injecting a thin film between the moving surfaces, like a balljoint?

afaik ....
joints are relined with hemisphericalish titanium/PTFE liners eg in young dogs and young people eg Andy Murray
refacing the bone as necessary for installation - young bone will then regrow and bond to the back of the titanium

old people can't be refaced as their bone won't regrow suitably
they need a replacement joint that has integral pegs - to be glued into counterbores in the bones (my words)

the peg-and-counterbore works fine eg in a knee joint - because the loads are endwise
but not in a hip joint - because there's lateral load which tends to spread the counterbore and walk around (my words)

these days there's no wear problem with replacement joints
but there's a problem with replacement hip joint loosening and pain - this has no remedy (my words)
ie worldwide 95% of non-hip replacements are good over at least 25 years - but only 54% of hip replacements
on average hip joints are replaced at a patient age of 68

my doctors get paid £200 to defer indefinitely hip joint replacement in those whose clinical condition justifies replacement
good old NHS !

Thanks, that is very interesting. some things I have wondered.

[Cold Fussion]

It's been very common on f1 cam shafts as well.
The nicest thing about it is that it's harder than most low friction coatings, even Ti nitride. The hardness of the coating only gets you so far, the rest of the system has to be well engineered too.

Do these coatings change the material hardness significantly? I would have thought the hardness would be more a function of the base material since the nano coatings are so thin.

[63l8qrrfy6]

Yes, hardness does increase dramatically even for a typical coating thickness of a few microns.