I have been reading about epoxy based some epoxy based bearing materials and I'm trying to understand what is the fuction of different constituents and their purpose.http://www.google.com/patents/US4329238
Abstract:An antifriction paste containing epoxy resin, molybdenum disulphide, graphite, aluminum, copper, alumosilicate and polyethylenepolyamine, the components being used in the following proportions (in parts by weight):
epoxy resin: 40-80
molybdenum disulphide: 15-30
The antifriction paste may also contain a solvent for the epoxy resin in an amount from 5 to 30 parts by weight. This paste is suitable for both small-and large-size friction assemblies. On the basis of this paste a solid lubricating coating with high antifriction performance is produced. Thus, a coefficient of sliding friction ffr. at a sliding speed V=0.06 m/s at a load P=10 kgf/cm2 is 0.2; linear wear rate Ih under the same conditions is 1.0.10-9, and service life is as high as 500 km.
So, what is the purpose of each part?
epoxy resin: 40-80. OK, this is obivious. Matrix.
molybdenum disulphide: 15-30. This is often last line of defense, Works under high load, slow speed?
graphite: 10-15, what is the ecological niche for this one? Isn't that little bit redandant with MOS?
copper: 5-10. Yup, other materials are not that "strong", glass fibre is common to supplement abysmal cold flow of teflon.
alumosilicate: 8-15, more hardness?
DIY version: on megathread....http://www.cnczone.com/forums/epoxy-granite/30155-epoxy-granite-machine-bases-polymer-concrete-frame-225.html
100 Grams total: powders should be in the 1 to 20 micron
50 grams epoxy 635 2:1 (with BYK A-525 and BYK W-969 if you have it.)
10 grams of Molybdenum disulphide powder or Hexagonal Boran Nitrite.
10 grams Graphite powder (still wondering why on this one).
10 grams 3M 200 Zeeospheres.
5 gram Tungsten Disulfide. (if you can't afford then up the teflon)
5 grams Teflon powder.
5 grams Aluminum powder. (probably can drop this and up the Zeeo's)
5 grams Copper powder. (probably can drop this and up the MoS2)
Lot of slipery stuff! I'm wondering mostly teflon. Works dry, low friction if there is some transfer onto counter surface. But mechanical properties are pretty low.
Some stuf is easy to get and straightforward to use. Some stuff is hard to obtain in right grain size and spesification.
Teflon is something I have mixed feelings:
1) Hard to glue. There is an activator for CA-glue. Surface treatment for epoxy is harder.
2) Another bearing surface must be apropriate surface roughness, or there is too little of of transfer or excessive wear.
3) PTFE has large cold flow and needs something on mix.
This is so far just and academic entertainment, but I just might order some graphite and metal powder, because I seem to need some dry lubricants every now and then.
Now the question: Ideas of two different mixtures? Another for way oil and another dry.