Diamond Like Carbon

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Big Tea
99
Joined: 24 Dec 2017, 20:57

Re: Diamond Like Carbon

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Anyone with an interest in this may like this
and the follow on next Wednesday.

He has a slight speech impediment, but CC is available if you have trouble.

It is mostly glossing through and twice as long as it needs to be but prob still worth the 20 min
When arguing with a fool, be sure the other person is not doing the same thing.

TimW
36
Joined: 01 Aug 2019, 19:07

Re: Diamond Like Carbon

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Cold Fussion wrote:
21 Jun 2020, 18:37
humble sabot wrote:
10 Jun 2020, 08:48
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.
Depends on the scale (scale as in size) you are measuring on. Micro scale hardness will increase dramatically (e.g. scratch resistance), but large scale hardness would hardly be affected (so same as base material hardness,
hammer would leave same size dent).

I guess exactly as you thought it would be.

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Andres125sx
166
Joined: 13 Aug 2013, 10:15
Location: Madrid, Spain

Re: Diamond Like Carbon

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Big Tea wrote:
27 Jun 2020, 20:56
Anyone with an interest in this may like this
Indeed, very good video explaining everything, from composition to current problems and aplications =D> =D>

Cold Fussion
93
Joined: 19 Dec 2010, 04:51

Re: Diamond Like Carbon

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TimW wrote:
27 Jun 2020, 21:42
Cold Fussion wrote:
21 Jun 2020, 18:37
humble sabot wrote:
10 Jun 2020, 08:48
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.
Depends on the scale (scale as in size) you are measuring on. Micro scale hardness will increase dramatically (e.g. scratch resistance), but large scale hardness would hardly be affected (so same as base material hardness,
hammer would leave same size dent).

I guess exactly as you thought it would be.
That makes sense, thanks.

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strad
117
Joined: 02 Jan 2010, 01:57

Re: Diamond Like Carbon

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Wear factor is what I would be concerned with and the slipperiness . The mentioned Teflon impregnated pistons were like wet ice on wet ice.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss

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humble sabot
27
Joined: 17 Feb 2007, 10:33

Re: Diamond Like Carbon

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Cold Fussion wrote:
21 Jun 2020, 18:37
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.
Surface hardness,specifically.
On high wear, but low load cases, like a cylinder wall, using a hard coating on relatively soft aluminium pistons or bores is fine, but when you have strong eccentric moments, like a camshaft or a crankshaft, the base material has to have a higher base surface hardness to support the surface treatment. If not it'll simply flake off, or be pushed into the surface.
the four immutable forces:
static balance
dynamic balance
static imbalance
dynamic imbalance