Duralcan Brake Rotors

[Faterooski]

I was wondering if anyone has any information on or knows where to get "duralcan." It's apparently pretty good stuff for brake rotors, or so a team member says. I know McGill and Queens both used it previously, so if any of those guys could chip in with some info, it'd be much appreciated. Thanks!

[Matt Gignac]

Quite a few years back, we were sponsored by Alcan (hence the trade name duralcan) for this material, and they casted us four sets of discs, which we've been re-using over the years. Last year, we needed new ones and we contacted them, but they told us that they couldn't make any money off this material, so they ditched it and aren't producing it. Apparently they may be coming with something new in the next year, along the same lines (I heard ceramic fiber instead of ceramic particles as the reinforcement).

We have a few materials engineering guys on the teams, and we're going to try to cast our own discs out of the sasme mix as duralcan. It doesn't seem to be too hard, but then again there's a prof here that does research with metal mesh composites that's here for advice for manufacturing.

Oh, and it makes for very light discs that are quite consistent though a bitch to machine

Matt Gignac
McGill Racing Team

[Faterooski]

So I take it that this stuff is not something you can buy in plate or sheet form? Also, it's tough to machine, but do you know of anyone laser cutting the stuff or waterjetting it? I know certain laser machines are for steel only, and even for ones that will do aluminum, this stuff may really trip it up. Thanks for the help.

[John Valerio]

hey guys
we have indeed run the duralcan since before my time here. it is also true that alcan (now novelis) is out of production so we've been using what we have left over, which thankfully is more than one set.
the duralcan is good for rotor material, it's light as hell, but you have to watch out for excessive expansion under constant load (like having too much friction in your pedal assembly...whoops) and they are a real pain to machine. we had to bring in a diamond cutter to turn them down to size, not the most convenient of processes.

[TG]

I know it's been brought up on other threads, but what pads have you guys been using with these rotors?

There is more than one producer of Al MMC's out there. As it has be stated, the are different types of reinforcement, continuous and particulate. You also have to look at the ceramic content added to the matrix. Other factors are the particulate/fiber size and whether it is just cast or is made wrought. I know in machining Al MMC, the smaller the particulate size, the easier it is to machine (however you still need PCD coated tooling to do the job). Fiber reinforced Al MMC you probably can't machine with traditional tooling, although I haven't looked into it. I'm not experienced with water-jet and laser cutting, but from what I've seen, they've advertised them as being able to work with MMC's.

[Jersey Tom]

Going along the lines of what others have said, I would *highly* reccomend waterjetting any MMC if at all possible rather than machining them conventionally. Its very abrasive and will just eat your tools, unless you're using diamond. And I have no desire to go out of my way and buy diamond tools for wads of money when you could get a waterjet place to sponsor you and crank the things out.

[John Valerio]

i agree that waterjetting MMCs is the way to go if it's available to you, yet your options are limited when you have a 7" disc and you need to turn it down from .210" to .180"...that'd be quite the waterjet set up.
and in terms of pads, soft compound pads are the way to go. if you use standard wilwoods you'll find your rotors being worn away along with the pads.
another comment about the duralcan, one complaint about our car, although fairly qualitative, is that the brakes have no bite, which i think is unavoidable due to the material properties, mmc or no mmc.

[John_Burford]

For those thinking about or running Alumuinum MMC rotors, make a set of steel rotors as back-up plan. Through trial and error I've found that they are not a good match with a FSAE car. If the cost and manfucturing problems don't stop you, then the performace problems should. I say "should" because few teams use as much brakes as they should. In ten years, I have not see a set of rotors survive on a car driven by a driver who used the brakes to their limit. The rotors would fail by creep at the attachment points, localized melting on the friction surface, or melt completely off of the car and on to the track.