replacing hard chrome coating on piston

[grisen]

Hi,
I'm looking for an alternative surface treatment / coating to replace a traditional hard chrome coating on a piston used in brake calibers.
I already consider plasma nitriding / plasma oxidation processe, but i'm wondering if a HVOF treatment could do the job as well? or other treatments like DLC etc.

looking forward for you feedback.

Have nice day

[djewell]

HVOF/HVAF will provide a very nice replacement for brake pistons. There are lots of materials available which will provide the wear protection and corrosion resistance of chrome, but you are going to have to grind the coating to make it smooth. That is where you will need to get into an economic calculation to decide which material to use. You could put tungsten carbide on there, but it will be more expensive than some kind of nickel or iron based alloy. Do you have multiple pieces to coat so you can take advantage of some economies of scale, or do you only need to do one or two pieces?

[Vadim Verlotski]

Hi,
I'm looking for an alternative surface treatment / coating to replace a traditional hard chrome coating on a piston used in brake calibers.
I already consider plasma nitriding / plasma oxidation processe, but i'm wondering if a HVOF treatment could do the job as well? or other treatments like DLC etc.

looking forward for you feedback.

Have nice day

Hi grisen,
HVOF / HVAF for such small parts as pistons of the brake calipers is perhaps better than hard chrome, but several times more expensive. For small parts, can be much more economical other galvanic (chemical) layer or PVD. For example, chemical nickel after a heat treatment at 400 ° C is a better corrosion and wear resistant alternative to hard chromium. One can also recommend a galvanic nickel plating under the hard chromium, which improves the corrosion resistance.
DLC coatings are the best option for this application, but it is quite expensive.

[Guner]

There is equipment in Belarus, which is much cheaper substitute for chrome plating in comparison with HVOF / HVAF. It is
activated arc metallization or Hipersonic metallization.