Tell me all about titanium nitride

.blitz
.blitz Posts: 6,197
edited January 2011 in MTB general
Allegedly it's used on fork sliders to make them slippery so it seems strange that it should be used as a coating on disc brake rotors :?

Presumably the coating wears off after a while - or does it? Special pads required?

Any info appreciated.

Comments

  • nicklouse
    nicklouse Posts: 50,675
    it is also used one drill bits and other things.

    Mmm
    Tried and tested, awesome light one piece stainless steel design.



    Blingy gold titanium nitrate coated versions which resist corrosion,
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • captainfly
    captainfly Posts: 1,001
    I thought it was used to protect the underlying metal, as it is very tough and prevents wear it is also scratch resistant and stop corrosion etc.. As for its use on suspension and brake disks it is like asking why they are both stainless steel :roll:
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    Mongoose Teocali
    Giant STP0

    Why are MTB economics; spend twice as much as you intended, but only half as much as you wish you could afford? :roll:
  • .blitz
    .blitz Posts: 6,197
    captainfly wrote:
    As for its use on suspension and brake disks it is like asking why they are both stainless steel :roll:
    Sorry for being a bit thick but it seems to me that using titanium nitride on fork stanchions to make them more slippery would be at odds with the requirements for a disc brake rotor?
  • whyamihere
    whyamihere Posts: 7,713
    TiN is used as a very hard coating, rather than a particularly slippy one. If the stanchions on a fork get chipped or worn, then they'll obviously start to rip the seals apart, destroying the performance of the fork. The TiN coating prevents this to some extent, so can be seen as keeping the interface 'slippy' rather than making it slippier. Think of it as like diamond rather than Teflon.

    There's various grades of stainless steel, some hard, some less so. If they're using one of the 'softer' grades of stainless, and it's significantly softer than the steel used in normal rotors, then the wear rate could be unacceptable, justifying the TiN coating for longevity. I reckon it's probably more likely to just be to make them look nice though.
  • nicklouse
    nicklouse Posts: 50,675
    the friction Coefficient of TiN does also vary. (not sure how but...?

    but I think it is still the second line. First word.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • .blitz
    .blitz Posts: 6,197
    whyamihere: thank you.

    I agree that the rotors look bling but wouldn't the coating wear off quickly on the braking surface?
  • whyamihere
    whyamihere Posts: 7,713
    .blitz wrote:
    whyamihere: thank you.

    I agree that the rotors look bling but wouldn't the coating wear off quickly on the braking surface?
    It's not so much that the TiN coating will get worn off, as the pad material is softer. The way that brakes bed in is that a small amount of pad material gets transferred onto the rotor, and it's this surface that gives the good braking. So you won't have the nice gold colour on the braking surface, no. It will stay on the rest of the rotor though.
  • Anonymous
    Anonymous Posts: 79,667
    Probably isn't even TiNi. Most of the cheap drill bits aren't. You just cannot buy a 100-piece TiNi coated drill set for a fiver.
  • supersonic
    supersonic Posts: 82,708
    I've seen it wear off rotors, and off forks. Eventually it does come off.
  • captainfly
    captainfly Posts: 1,001
    .blitz wrote:
    captainfly wrote:
    As for its use on suspension and brake disks it is like asking why they are both stainless steel :roll:
    Sorry for being a bit thick but it seems to me that using titanium nitride on fork stanchions to make them more slippery would be at odds with the requirements for a disc brake rotor?

    It is the interaction between materials and their surface stuctures that are important, oil and bush material in forks, and brake pads in brakes. If you get oil on disk rotors you will see how slippery they are and if you use a brake pad on a fork stanchion it will be abrasive. I just can think of the right words to explain the lack of smoothness of the surface micro structure and how they work.
    -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
    Mongoose Teocali
    Giant STP0

    Why are MTB economics; spend twice as much as you intended, but only half as much as you wish you could afford? :roll: