Metal finishing Q&As since 1989

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Diamond like carbon coating

Sir/Mam,

I WOULD LIKE TO KNOW WHICH IS THE EASIEST AND CHEAPEST WAY FOR DIAMOND LIKE CARBON COATING.

IS THE BASIC MATERIAL HARDNESS WILL EFFECT COATINGS HARDNESS?

CAN WE DO IT ON METAL AND NON METAL BOTH?

ARE MACHINE ARE AVAILABLE FOR THE SAME? IF NOT, THEN CAN IT BE ASSEMBLED AND HOW?]

MALAYA JOHARI

2006

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2006

You can deposit DLC by plasma technology, but you will need to ensure the sp2:sp3 ratio is correct. Just using plasma and carbon will not give you a good DLC layer and it will almost certainly be spongy and loosely bonded. There are numerous patents on the technology, so I would suggest you read them before embarking on your own processing. Once you have the correct sp2:sp3 ratio, adhesion can be a problem with many metals, but there are techniques that will overcome this. The thickness of the DLC will be very thin, so bulk hardness will be dominated by the substrate, but micro hardness will be dependent on the sp2:sp3 ratio. Again, all of this is covered by patents. You can buy such equipment from reputable vacuum technology (PVD/CVD type plant) suppliers.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK