+- 6.5 Grendel Forum (https://65grendel.com)
+-- Forum: MARKSMANSHIP TRAINING FORUM (https://65grendel.com/forumdisplay.php?fid=6)
+--- Forum: Technical Knowledge (https://65grendel.com/forumdisplay.php?fid=28)
+--- Thread: Coatings discussion QPQ/Melonite, Cerakote, NP3+, + others (/showthread.php?tid=12722)
Coatings discussion QPQ/Melonite, Cerakote, NP3+, + others - The Profit Joseph Sith - 02-12-2017
Looking for good Specs/Articles/links and in depth technical discussion about the current leading coating technology. If you have any questions comments or whatever please contribute!
It's my understanding that NiB/NiBX is a very hard coating with grain structure more similar to anodizing that looks like a honey comb/matrix of pillars with very round slick domes on the top (surface). But once those "domes" wear are actually pretty rough in texture and still VERY HARD could wear faster and is basically like a sandpaper.
Where as NTFE/ or Robar NP3+ are slightly softer surface plating impregnated with sub micron PTFE/teflon particles, which is supposed to wear ALOT better over time than NiB/X
Some pretty good info here regarding their NP3+
https://robarguns.com/custom-firearm-finishes/
Anyone got any in depth info reviews on Cerakote microslick vs. Robars Rogaurd©/® i know Robar advertises thiers is Moly based is this the case with Cerakotes Micro Slick?
Here is a pretty good article http://www.burlingtoneng.com/wear_resistance.html Mr. Explorecaves posted a few days ago over in the 12" GB thread In regards to QPQ/Melonite/Carbon nitriding we were discussing the barrel finishing processes
Sorry, i just realized this is under the marksmanship group thread. If mod can move it to where they see fit... Maybe the "semi auto" section.. would be more relevant and have better visibility for others. Thanks!
Coatings discussion QPQ/Melonite, Cerakote, NP3+, + others - Eric - 02-19-2017
Hi Joe, this is something I looked deeply into a while back and really nerded out about. This being the technical forum, I'll lay out what I learned, for what it's worth.
First, there are some good overviews (and opinions) I liked from coating engineer Bill Riehl here and here.
Electroless nickel (EN) is great for adding corrosion resistance to steel, as well as reducing friction. High phosphorous EN is better at corrosion resistance, but softer and wears more than low P. Add in some boron and you start to get NiB/NiB-X, and it's harder and much lower wearing, though not as slick. Check out this chart. The Taber wear is a lowest for the low-mid B column, which is roughly the NiB. Adding in PTFE (Teflon) particles reduces the friction even further from normal EN, but it still doesn't wear as well as NiB. The Taber wear I've seen from PTFE/NP3 is about 20, which isn't great. There are tons of articles on this, like Liew, et. al (2013). Evaluation on tribological design coatings of Al2O3, Ni–P–PTFE and MoS2 on aluminium alloy 7075 under oil lubrication. Materials and Design, 48©, 77–84. http://doi.org/10.1016/j.matdes.2012.08.010.
The best of all is probably to embed particles of not only PTFE, but also tungsten, but as far as I know those aren't commercially available (though I believe Bill's company Black Fire Engineering is working on the latter?). Here is an overview of the wear benefits of tungsten additives.
Roguard, Armor Tuff, Cera Hide, and I assume Cerakote's Micro Slick are polymeric/epoxy coatings with embedded lubricants like PTFE or MoS2. My impression is these are great for superficial and relatively low-wear applications, not so much for internal or high force applications.
The cool thing about EN overall is that you can spend a ~$150 for a kit and gear, and coat a bunch of parts for yourself.