Al-MMC brake rotors

[Nguyen Ta]

Hi, I am currently investigating using Al-MMC (reinforced with SiC) to manufacture brake rotors out of.

I am just having some trouble finding information about this material.

What are other team's opinions on the material ? I've noticed Swinburne used them in 04 but their 06 car seems to have switched back to grey cast iron.

Also I seem to be hitting brick walls regarding the pad compound that should be used with Al-MMC discs. Wilwood's off the shelf Al-MMC disc recommends Wilwood purple brake pads. But it doesn't seem provide specifics about the pad.

Could someone point in the right direction regarding pad compounds for Al-MMC discs?

Lastly, regarding manufacturing, does anyone in Australia cast Al reinforced with SiC? How about the machinability of the material, being quite hard did it require special tooling ?


Your help is appreciated.

PS. I've searched the forum and couldn't find answers.

[Nguyen Ta]

Hi, I am currently investigating using Al-MMC (reinforced with SiC) to manufacture brake rotors out of.

I am just having some trouble finding information about this material.

What are other team's opinions on the material ? I've noticed Swinburne used them in 04 but their 06 car seems to have switched back to grey cast iron.

Also I seem to be hitting brick walls regarding the pad compound that should be used with Al-MMC discs. Wilwood's off the shelf Al-MMC disc recommends Wilwood purple brake pads. But it doesn't seem provide specifics about the pad.

Could someone point in the right direction regarding pad compounds for Al-MMC discs?

Lastly, regarding manufacturing, does anyone in Australia cast Al reinforced with SiC? How about the machinability of the material, being quite hard did it require special tooling ?


Your help is appreciated.

PS. I've searched the forum and couldn't find answers.

[rjwoods77]

Do a search on the last couple brake topics. One team chimed in about being knocked out of comp because of a cracked Al-MMC rotor that no replacement could be found. One of the advanatages of steel. I would do a full thermal analysis and then fit the appropriate material first if you already haven't. This will tell you if Al-MMC is even viable for your car to begin with.

[exFSAE]

My first question would be, why Al-MMC? Its cool stuff, and its light, sure.

When designing brakes you want to up your braking torque so you can use all the tire's capability. Mo' torque. Teams have a hard enough time passing brake as it is.

Wilwood has pads for aluminum but their coefficient of friction is way down on those designed for steel/iron (goes against the Mo' Torque concept).

You will have to get diamond tooling to machine Al+SiC. Either that or watch your carbide and steel tools abrade away to nothing My reccomendation would be to waterjet. Well. It would be to go with steel or iron.

[js10coastr]

Lotus uses the stuff... It's pretty neat stuff. If you can find "the story of the Lotus Elise" theres a little bit of info on it there. They mentioned the manufacturer of the brakes, but I can't remember it off the top of my head.

[TG]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by js10coastr:
Lotus uses the stuff... It's pretty neat stuff. If you can find "the story of the Lotus Elise" theres a little bit of info on it there. They mentioned the manufacturer of the brakes, but I can't remember it off the top of my head. </div></BLOCKQUOTE>

I know they don't any more, but I do not know the reason for why they don't any more.

I know the show you are talking about... it was entitled something like "Project M1-11" or something like that (M1-11 was the working project name for the 1st gen Elise). It was a great show, a bit long at over 2 hours, but had a lot of information on the entire development of the Elise.

[Nguyen Ta]

Hey guys,

Yeh I've seen the Lotus Elise video you're talking about.

I was just flipping through it again and one of the engineers mentioned that there were other road car's that used MMC materials on the rear and the Elise was going to be the first to use it on all four wheels.

Does anyone know which vehicles used it on the rear? Also I think I came across a road bike with Al-MMC discs once. Does anyone know of any road bikes that use Al-MMC discs?

According to the documentary, Lotus also noticed cracks in their initial design. The braking plate and the hub were in the same plane which caused stressed in the hub when heated up.

In their redesign has the hub was offset (essentially having a hat) within the disc to allow the brake plates to expand and not cause as much stress in the hub.

Rob:
Are you saying Al-MMC might fail the thermal analysis?
Also your name seems to pop up often when I did a search on this topic, did you also look into them at one stage?

exFSAE:
Yeah the primary reason is reduction in unsprung weight. But if I can't get the same braking torque out of them... I might have to give it a miss.

Does anyone know of any other pads I can use with Al-MMC? Maybe get the first generation Elise pads cut to shape?

[Peter7307]

Nugen,

There is a company in Sydney called Disc Brakes Australia who are commercial suppliers of disc brakes.

They have a very helpful tech section and should be able to help with company names dealing in your intended component mix and other info if you ask.

Website is:

www.dba.com.au

Cheers , Pete.

[kwancho]

Give Tom Chamlee a call at Swan Metal Composites.
We bought brake buttons from him, but he was really eager to discuss an MMC package for FSAE teams.
425 398 0588
http://www.swancomposites.com/