Why the diamond-like-carbon coating works well with water?

[Nahahahah]

Hi everyone.
I have a question with a DLC (Diamond-like-carbon) coating.

In many papers, the DLC coating without hydrogen (a-C or ta-C) shows very good frictional properties and wear resistance with water lubrication.

I'm studying on eco-friendly engineering, so I surprised that water can be used as lubricant in engineering devices with this coating.

But why the DLC coating shows that good friction and wear properties with water lubrication??

Is it by chemical reaction? or just it does not make rust with water? (then, why not stainless steel??)

I'm searching the papers to know the reason, but it is not easy...

Please help me!

 

[Baluncore]

I think using water as a lubricant has a couple of benefits. It provides a replaceable sacrificial layer that can wet and protect the DLC surface by binding with any free surface bonds. Diamond is sensitive to heat, the water cools the surface and so prevents burning that might happen with a surface exposed to air and high contact pressures.
https://en.wikipedia.org/wiki/Diamond-like_carbon#Tribology