PTFE and Anodized Aluminium Surfaces

[jkdmag]

Hoping for an explanation as to the advantages of low friction/wear surfaces on motorcycle fork legs. Current designs have PTFE coated bushes working with hard chromed steel and aluminium tubes, in an oil environment.

Marketing claims are made for significant improvement in wear and friction performance between the PTFE bushes and the aluminium tube after hard anodizing of the aluminium. Similar performance improvements are claimed for the steel components by substituting other coating for the hard chrome, e.g. TiN or DLC.

Given the low friction/wear properties of PTFE and hard chrome, why would there be any improvement to be gained by the changes to the alternative surface treatments to the steel, as listed above.

What advantage does hard anodized aluminium have over non-anodized aluminium when working with PTFE coated bushes.

Also, believe PTFE coating performance can be degraded when exposed to lubricants, is this a true statement.

 

[coatingengineer]

Hello. Sounds like you have yet to see "failure mode", yourself, using conventional surface treatments like hard chrome. Nevertheless, there may be some advantages. Specifically, in boundary lubrication (e.g. oil environments), PTFE can serve you well in overcoming static friction and periodic dry intervals. Also, depending on "PV-WEAR" (applied pressure x rub velocity), surface treatments like hard anodizing (with PTFE seal) may significantly extend aluminum life. No chemistry between oil and PTFE; degradation is not an issue.

William Gunnar

http://www.IndustrialCoatingsWorld.com