Friction reduction on Aluminum

[Yorkie]

I need the help of the brain trust. I’m looking for a coating/plating/something that will reduce the friction between two aluminum extrusions. The parts slide over each other and I’ve tried silicone and Teflon sprays to lower the friction but after 10-20 slide motions the pull force climbs back to the pre-spray levels. I’ve also tried polishing the parts but seen no real improvement. Any suggestions like anodizing or media tumbling? Thanks.

[fanaudical]

Look up General Magnaplate. They do some great coatings.

[Sooner or later]

I second General Magnaplate. I used them on several industrial applications. I visited the Arlington, Tx facility many times. Great customer service. Gaglion options. Suppled me with multiple samples until I found the product that met my our needs. Ended up using Plasmadize procsss

[LWJ]

Delrin? I used to sell a lot of extrusion. Don’t really know a good coating. I will watch closely.

[908/930]

Hard Anodizing at least one part should help lots, not all anodizers can do hard, more cost but way better. Some can also do teflon hard. It been a while since i have had any parts done, call a local shop and ask what they recommend. Also the type of aluminium could be a problem, I always used 6061, some alloys can not be anodized, also if you are running tight tolerances, you will loose about .001"-.003" off each surface, usually not a problem.

Aluminium against aluminium is not a good combo, usually a hard against a soft material works well.

[908/930]

Not sure how much load you are dealing with but there are also some PTFE fiber-glass film tape's available, you could try sticking that on one or both sides.

[Evans, Marv]

If the coating route is less than practical for you and you want to stick with sprays, I've had good luck with Boeshield T-9 on lots of applications. It was supposedly developed by Boeng for "corrosion protection and lubrication of aircraft components." Do a search on it to get an idea if it may be something you want to try. It's not cheap as sprays go. I'm sure spray applications will universally have fairly short life spans and need to be reapplied on a regular basis. But any coating will reduce the amount of clearance between the sliding surfaces, so a spray that works decently might be your only option.

[Arizona_928]

Electroless nickel coating.
Really popular on the AR style bolt carriers.
MoS2 grease
WS2 grease

[LWJ]

Ok. Here is something I see in mountain biking. It is hard anodizing with molybdenum.

KASHIMA-COAT.COM What is KASHIMA COAT?

[Yorkie]

Thanks guys. I have a 25lb load that has to slide back and forth in desert conditions. What is key is they the pull load does not increase over time by more than 30%.

[DanielDudley]

Graphite Dry Film Lubricant.

[sc_rufctr]

Could you redesign the assembly so that you could incorporate a steel bearing material?

My concern is long term.
You could reduce friction using a variety of methods but at the end of the day it's still alloy on alloy.

Take a look at a good quality bike derailed. Note the steel pins and inserts at the pivot points... All steel or Titanium (Ti-Campys Super record).

[Yorkie]

Originally Posted by DanielDudley

Graphite Dry Film Lubricant.

Tried that and after about 20 cycles is gone.

[sc_rufctr]

Yorkie, Any chance of posting a picture of the device?

[dad911]

Are you using a custom extrusion or a T-slot like 8020?

Can you convert to 8020? They have simple linear bearings & pads made of UHMW available.

[HardDrive]

I think you have a design problem, not a lubrication problem.

[Sooner or later]

What are exactly trying to do? Pics would help.

[Captain Ahab Jr]

Originally Posted by HardDrive

I think you have a design problem, not a lubrication problem.

I'd agree with this

Can you fit a thin PTFE strip between the 2 aluminium parts?

[Rusty Heap]

strong magnetic repulsion.........mag lift rail, or linear rail bearing.

what is payload, and stroke length.

[1990C4S]

Originally Posted by sc_rufctr

My concern is long term.
You could reduce friction using a variety of methods but at the end of the day it's still alloy on alloy.

^^^ This is the problem.

You need appropriate bearing surfaces. Aluminum on aluminum is doomed to fail. Coatings are a short term solution.