Tungsten carbide rotors

[LeakySeals]

Watching the weekly MotorWeek program they test drove a brand new Porsche Cayenne. They mentioned the rotors.. made of tungsten carbide. Supposedly they don't rust warp or create much dust.

I thought the dust came from the pads so I'm wondering how this is possible?

https://newsroom.porsche.com/en/chr...-pscb-matthias-leber-weissach-14589.html

 

[RooflessVW]

One third the cost of PCCBs is still a whole [censored] lot.

Very interesting technology.

 

[maxdustington]

Not made of, just coated with.

Pretty cool, the article mentioned the brakes perform better above 600c. I wonder if this will trickle down to tow packages on trucks. If the components were 2-3x the price of grey iron brakes but instead of fading, got better at high temps I'm sure serious towers would be interested.

What happens when you wear through the coating and your are into the grey iron part of the rotor with the pads designed for the coating?

The only downside is that the rotors and brakes are a system now. I wonder how many of those Cayennes will have normal brakes on them once that first set of rotors wear out. I assume the parts are going to be pricey, and they only last 30% longer than grey iron brakes. I doubt the second owner who paid half what the first did will drop the coin for those expensive components just to avoid brake dust.

 

[Eddie]

Tungsten carbide is and extremely hard and long wearing surface finish. Never heard of it in rotors but, typical in lath metal cutting tools. Ed

 

[demarpaint]

It could be great. I'll let the early adopters report back before diving in. I won't be needing a brake job for another 3 years or so so I'll have plenty of time to see how well they do.

 

[KGMtech]

This could be a way for OEM's to further reduce weight. Coated rotors, set to be at the thinnest end of thickness = lowest unsprung weight, the coating prevents further thinning?

hmmmm??

 

[RayCJ]

LOL: The first guy that tries to resurface one of those rotors in a brake lathe is going to get a real surprise!

 

[Eddie]

+1. A diamond faced rotary wheel might be the only way. I suspect that the hardened surface is only a few thousands thick, so that precludes any resurfacing. Ed

 

[RayCJ]

Originally Posted by Eddie
+1. A diamond faced rotary wheel might be the only way. I suspect that the hardened surface is only a few thousands thick, so that precludes any resurfacing. Ed


Finally got around to reading the whole article... The coating (Tungsten Carbide) is 100 micrometers thick (translates to 0.00394 inch) so yeah, about 4 thou (0.0001 mm) thick. The article wasn't perfectly clear but, it's applied in a heat deposition process that sounded similar to arc spray transfer. It later mentions that the pads eventually polish the surface like a mirror and the rotors will have about 30% more service life vs cast iron. And finally, it requires special pads to be effective.

I'm curious about service cost and wonder how the economics play out for non professional race team (i.e. consumer) applications.

Ray

 

[Kruse]

I'd like to take one of these rotors down to the local O'Reilly auto parts store and watch one of their 18 year old counter techs try to lathe it.

 

[Eddie]

Many years ago Porsche optional HP pads/rotors for daily drivers were an extra $2,800 on a new vehicle so I suspect these replacement costs for Pads/rotors would be ~ $4,800 plus labor to install or ? Ed

 

[hatt]

Originally Posted by Kruse
I'd like to take one of these rotors down to the local O'Reilly auto parts store and watch one of their 18 year old counter techs try to lathe it.

I doubt anything spectacular would happen as thin as the coating is. The brittle tungsten carbide would would simply chip away.

 

[Ws6]

Originally Posted by maxdustington
Not made of, just coated with.

Pretty cool, the article mentioned the brakes perform better above 600c. I wonder if this will trickle down to tow packages on trucks. If the components were 2-3x the price of grey iron brakes but instead of fading, got better at high temps I'm sure serious towers would be interested.

What happens when you wear through the coating and your are into the grey iron part of the rotor with the pads designed for the coating?

The only downside is that the rotors and brakes are a system now. I wonder how many of those Cayennes will have normal brakes on them once that first set of rotors wear out. I assume the parts are going to be pricey, and they only last 30% longer than grey iron brakes. I doubt the second owner who paid half what the first did will drop the coin for those expensive components just to avoid brake dust.

Really bro? My [censored] lawnmower blades are TC coated. This should not cost "1/3 of PCCB". BS on Porsche.

 

[Ws6]

Originally Posted by hatt
Originally Posted by Kruse
I'd like to take one of these rotors down to the local O'Reilly auto parts store and watch one of their 18 year old counter techs try to lathe it.

I doubt anything spectacular would happen as thin as the coating is. The brittle tungsten carbide would would simply chip away.

It would legit jack up the cutting tool.

 

[Pew]

Originally Posted by maxdustington
Pretty cool, the article mentioned the brakes perform better above 600c. I wonder if this will trickle down to tow packages on trucks. If the components were 2-3x the price of grey iron brakes but instead of fading, got better at high temps I'm sure serious towers would be interested.


Proper semi-metallic pads for the could easily achieve that.

 

[nthach]

Isn't GM using a similar process on their new brake rotors these days or they are using a different method?

 

[A_Harman]

Originally Posted by RayCJ
Originally Posted by Eddie
+1. A diamond faced rotary wheel might be the only way. I suspect that the hardened surface is only a few thousands thick, so that precludes any resurfacing. Ed


Finally got around to reading the whole article... The coating (Tungsten Carbide) is 100 micrometers thick (translates to 0.00394 inch) so yeah, about 4 thou (0.0001 mm) thick. The article wasn't perfectly clear but, it's applied in a heat deposition process that sounded similar to arc spray transfer. It later mentions that the pads eventually polish the surface like a mirror and the rotors will have about 30% more service life vs cast iron. And finally, it requires special pads to be effective.

I'm curious about service cost and wonder how the economics play out for non professional race team (i.e. consumer) applications.

Ray


If the rotors only last 30% longer than cast iron, I don't see it being cost-effective. The coating probably adds more than 30% cost to the rotor, and having special pads only makes the system more expensive. GM probably gets a bigger improvement in rotor life with their nitriding process.

 

[A_Harman]

Originally Posted by nthach
Isn't GM using a similar process on their new brake rotors these days or they are using a different method?


It's called ferritic nitrocarburizing, and GM has been using it since 2008:


https://www.motortrend.com/news/gm-...-brake-rotors-on-selected-models-140867/