HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  RESOURCE CENTER  |  INDUSTRIES
REGISTER   |   LOGIN   |   HELP
Blogs
Engineering Materials

Aluminum Composite to Lower Weight in Brake Rotor

NO RATINGS
< Previous Page 2 / 2
View Comments: Oldest First|Newest First|Threaded View
<<  <  Page 2/3  >  >>
Dave Palmer
User Rank
Platinum
Re: Michigan Winter
Dave Palmer   2/16/2012 11:08:33 AM
NO RATINGS
@wb8nbs: The gunmetal gray color of friction ring in the rotor in the picture makes me think that it is probably hardcoat anodized, so it is not just bare aluminum.  All other things being equal, I'd expect anodized aluminum to hold up a lot better than bare cast iron.  In fact, I'd even expect bare aluminum to hold up better than bare cast iron.

On the other hand, connecting an aluminum brake rotor to a steel wheel hub could be a recipe for galvanic corrosion of the aluminum.  Galvanic corrosion between steel hubs and aluminum wheels is also a common problem.  In either case, a thick coat of antiseize between the two parts might help to prevent corrosion by galvanically isolating the parts from one another.

kleetus
User Rank
Silver
Re: Yet another strategy for weight reduction
kleetus   2/16/2012 11:35:24 AM
NO RATINGS
I can't wait to see a $500 brake rotor for a $10,000 car. Materials will be 10% of the vehicles value. Can you picture this repair on a 5 year old chevy cavalier or equvalent vehicle? lol, I can't...

There comes a point where practicality and reality need to mix. Cna this be done, sure, but when I can go out and purchase an $80 brake rotor for a 1 ton truck, and instal it myself, I shudder to think what this new material would cost.

Remember when plastic bumpers were supposed to make cars cheaper? yeah... now it costs over $1k to get the stupid thing repainted when some jerk dings you up in a parking lot, where the metal one didn't show the mark in the first place.

 

Neat idea, but until it's economically feasible, it's a waste of time... much like EV's without gov't subsidation (which still comes from our pocket).

Dave Palmer
User Rank
Platinum
Re: Metal matrix composites
Dave Palmer   2/16/2012 12:28:36 PM
NO RATINGS
@JimT: According to the brochure on REL's website, the material can only be machined using diamond tooling.

Heat from braking will cause organic brake pads to off-gas.  The idea of a dimpled brake rotor is that the dimples provide space for the gases to expand into, supposedly minimizing brake fade.  This is the same idea behind cross-drilled brake rotors.  The supposed advantage of dimpled rotors over cross-drilled rotors is that a dimple doesn't reduce the cross-sectional area as much as a drilled hole, so the rotor is less likely to crack. (I say "supposedly" for both of these things because I have heard people dispute both of these claims, and I haven't seen any objective data one way or the other).

It's possible to make MMCs using powder processes, but they are more commonly cast (or, sometimes, cast into billets and then extruded).  One way to cast MMCs is by stir casting, in which the reinforcement is stirred into the molten aluminum.  Another way is by squeeze casting molten aluminum into a fiber pre-form.  Based on the brochure, it looks like this is what REL is doing.

Dave Palmer
User Rank
Platinum
Re: Yet another strategy for weight reduction
Dave Palmer   2/16/2012 1:15:54 PM
NO RATINGS
@kleetus: I agree with you about cost -- at least for the time being.  When I worked on aluminum MMC brakes, it was for military applications, where cost vs. weight considerations are very different than in the civilian market.  But a lot of work is being done to find cost-effective ways of producing these materials.

By the way, there is no such thing as a 5-year-old Chevy Cavalier, since 2005 was the last model year for Cavalier.  My Chevy Cobalt -- the model which replaced Cavalier -- is more than five years old.

John
User Rank
Platinum
Heat Vs. Stoppability
John   2/16/2012 3:30:43 PM
NO RATINGS
Is there any word on the stopping power Vs. heat buildup on these rotors?  I recently went from ceramic pads to metallic pads with new rotors all the way around.  There was nothing wrong with my old pads except for stress cracks from the heating and cooling cycle. 

kleetus
User Rank
Silver
Re: Yet another strategy for weight reduction
kleetus   2/16/2012 5:00:05 PM
NO RATINGS
@Dave Palmer: Lol... okay, maybe I'm dating myself with a cavalier, but your cobalt would be the same premise. A lower cost vehicle with a significant repair bill for normally wearable items.

Now having the price come down over time I can certainly believe, just look at cmputers, but there are a number of other items, like 'lubed for life' suspension components and u-joints that never lived up to the name, and were just as expensive if not more based on their novel idea that they are 'better'.

Time will tell.

William K.
User Rank
Platinum
Aluminum composite for lighter brakes
William K.   2/16/2012 5:10:58 PM
NO RATINGS
I have never had a rotor fail in an automotive disk brake system, but I have had many failures of the caliper mechanism over the years. The reason has been that Chrysler has consistently chosen designs for the caliper assembly that rust and stop sliding where they should. The results have been either brakes that drag and overheat, or brakes that only brake on one side of the disk, resulting in a buildup of an iron oxide material on the inoperative side, which has a much lower friction level, but is far more abrasive to the pads. This failure mode does destry the rotor, but not through any design error in the rotor or material.

The aluminum composite may be a very great improvement, but it would be very handy to find out about it's corrosion resistance to the southeastern Michigans salt brine roadways. If it can stand up to that test, where can we buy these rotors?

RICKZ28
User Rank
Gold
Re: Heat Vs. Stoppability
RICKZ28   2/16/2012 5:39:12 PM
NO RATINGS

Formula 1 racecar brake discs are made from carbon fiber composite.  I heard that the coefficient of friction increases as the F1 brake discs heat up, the opposite of cast iron brake discs.

http://www.formula1.com/inside_f1/understanding_the_sport/5284.html



Charles Murray
User Rank
Blogger
Re: Heat Vs. Stoppability
Charles Murray   2/16/2012 8:38:22 PM
NO RATINGS
If the automakers aren't taking a hard look at this, I'd be shocked. Cutting 30 lbs from the weight of a mid-size sedan is a gigantic change. Engineers typically fight to cut a pound or two from their vehicles. If they can cut 10 lbs, they're heroic. Thirty is off the scales.

Jerry dycus
User Rank
Gold
Re: UNSPRUNG Weight Reduction!
Jerry dycus   2/16/2012 9:12:09 PM
NO RATINGS
                  Does anyone know why Carbon brakes are not getting cheaper?  After all carbon isn't that expensive a feedstock.  How are they made?

                 They would be much lighter than even this advance with the lower weight advantages in handling and mileage.

                Some brakes come with retracting clip springs that pull the pads off the rotor.  In every EV I do I always check the brakes and many other drags like diff fluids, new low rolling resitance tires, aero mods, etc which can literally increase range 10-50%!!   Or cut the battery pack/cost/weight as much for the same range.

               Of course the best brake is one that doesn't have to stop all that excess weight most cars have by designing in lightness, KIS.

 

<<  <  Page 2/3  >  >>
Partner Zone
More Blogs from Engineering Materials
Inspired by the hooks a parasitic worm uses to penetrate its host's intestines, the Karp Lab has invented a flexible adhesive patch covered with microneedles that adheres well to wet, soft tissues, but doesn't cause damage when removed.
Engineers at the University of California, San Diego are designing a robotic arm that takes inspiration from the loose, flexible, yet very strong structure of the armored plates on a seahorse's tail.
Researchers at the Missouri University of Science & Technology have designed a new nanoscale material that can transmit light faster than the 186,000 miles per second it usually takes to travel through air.
It has often been said that as California goes, so goes the nation. This spring, the state's wind power is setting energy generation records and solar energy generation is expected to rise sharply during the second half of 2013.
The latest model of Liquid Robotics' Wave Glider autonomous, unmanned marine vehicle (UMV), the SV3, is reportedly the world's first hybrid wave- and solar-power-propelled unmanned ocean robot.
Design News Webinar Series
5/15/2013 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
5/22/2013 9:00 a.m. California / 12:00 p.m. New York / 5:00 p.m. London
5/29/2013 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
5/30/2013 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
Blogs from Our Sponsors
From Dell / Intel®
New Paradigms in Design Work
Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013    3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
From Dell / Intel®
Increased Workstation Performance Is as Easy as 'DPPO'
Trey Morton, Dell, 4/25/2013    2
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
From Dell / Intel®
Taking Some of the Grit out of Manufacturing
Kirsten Billhardt, Manufacturing Industry Marketing Strategist, Dell, 3/26/2013    5
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
May 20 - 24, Automation Technologies & Trends for Smarter Homes & Buildings
SEMESTERS: 1  |  2  |  3


DN Radio
Sponsored by
NEXT UPCOMING BROADCAST
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2013 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service