From what I've read, ceramic brakes(pads) are better than traditional brakes for the following reasons: they stop a car more smoothly; better brake recovery; they stop the car faster and are more durable. The only disadvantage is price.

What Auto manufacturers routinely build their cars with ceramic brakes?

Porsche. I understand the discs last many years, but are horrendoulsy expensive to manufacture. I think (don't quote me) that they are available on the 911TT and 911GT2

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John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

Mercedes-Benz equipped the CL55 AMG Formula 1 with ceramic brakes...I do not know if they are an option on any of the upper level M-B's yet...

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1995 black pearl/black Mercedes-Benz E420 :

Ferrari Enzo has ceramics too.

No, Enzo has Carbon Fibre composite disks.

(so I have heard)

But if you just use the ceramic pads alone, you will wear out you discs in no time

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Flash Gordon

2003 E500 BlackOpal/Charcoal

2004 Infiniti G35X

Actually all "ceramic" brakes are carbon-ceramic but people just call them ceramic. The term composite is just that, a composite of a whole bunch of elements with the major elements being carbon (in the form of carbon fibre for directional strength) and silica (better known in layman terms as ceramic for high heat absorption and dissipation properties).

eg. Porsche's system is called PCCB (Porsche Ceramic Composite Brake). The PCCB disc is made of specially treated carbon fibre silicated in a high-vacuum process at approximately 1,700 ºC.

Therefore, Enzos are running with "ceramic" rotors and pads.

I think we also need to differentiate between rotors and pads. I think jamesnj's original question was about pads but we all started answering about rotors and pads.

BlueDevil,

Thanks for pointing that out...he said "ceramic pads"...doh! Honda uses ceramic pads on their cars...my '96 Honda Accord EX-R V6 was equipped with OE ceramic pads on all four corners...the brakes on that car is quite good...my only complaint is they are a little "dry", especially after a car wash...and have a tendency to squeal when cold...other than that...no real complaints...

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1995 black pearl/black Mercedes-Benz E420 :

Thanks for clariying. To be honsest, the idea of simply using carbon fiber as a braking material seemed absurd to me. It would make since that it was mixed with a ceramic material. How do ceramic composite rotors differ in look from a traditional metal rotor?

BTW, sorry if I seemed rude in the above comment ... I didnt mean to come across as particurally sharp.

Cazzzidy,

No need for apologies.

I'll take a picture of my Enzo rotors for you (I wish!).

Actually it's got a dull matte finish compared to shiny metal rotors. It looks kind of like gray stone.

As you know ceramic is just too brittle in any form so the carbon fibre matrix is required to give it strength and the overall rotor is lighter than steel which is a big benefit of the these rotors. The others being better fade resistance (constant levels of friction at high temperatures), longer life (less abrasion), and for the pads better wet performance (doesn't absorb water).

However for any regular driver, these benefits are wasted on street driving (maybe the unsprung weight is the most beneficial).

Cazzzidy,

Here is a pix of a ceramic rotor from the CL55AMG F1 Edition...as you can see, Blue Devil mentioned that it has a dull finish:

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1995 black pearl/black Mercedes-Benz E420 :

I thought that ceramic/carbon brakes had to warm up significantly before they actually worked. I thought that is why they aren't used in street applications. Maybe manufacturers have fixed this.

p.s. There is such a thing as carbon-carbon composite which doesn't use a resin for a matrix. This would be OK for high temp application (like the leading edges of the space shuttle), but I don't know if this is related to the ceramic/carbon composite that is being used for brake disks.

Sholin

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What else, '73 MB 280 SEL (Lt Blue)
Daily driver: '84 190D 2.2 5 spd.

I think the issue about warm up is related to using ceramic pads with metal rotors. The different compositions translates to 2 varying coefficients of friction so the lower friction material must "catch" up with the other material before it works coherently.

Yes there are numerous C-C composite applications which do include brakes. But currently this is only for high-end applications (translation...very expensive). I did a quick search on the internet and found it is used for jet fighter brakes, race cars, and high speed trains, etc.

Carbon in this form (carbon fibre) is relatively delicate (fracture toughness) so the process to make the matrix is expensive. Think of carbon fibre as graphite or mechanical pencil re-fills. It's only strong once the matrix is complete. Even C-C composites use a coating of SiC to protect the composite from high temperature oxidation.

In the latest edition of Car & Driver (July 2003, p. 38) the write up of the Enzo..."a set of $6,000 carbon-ceramic brake pads and a $24,000 set of similarly constructed brake rotors"

Can you imagine what carbon-carbon would cost?!? Maybe it's Ferrari's markup.

Ouch, a $30k brake job (labor not included)...

One thing though is carbon has many allotropic forms. On one end of the scale is graphite (really soft) and on the other is diamond (really hard). I think the carbon in carbon fiber is somewhere inbetween with much more cross bonding than graphite. Carbon fiber is not pencil lead, it's much much stronger. It has somewhere around 300k psi tensile strength--well above graphite.

To make a carbon fiber composite, you impregnate this cloth which has extraordinary tensile strength with plastic resin. The composite then has the tensile strength of the fibers and the compressive strength of the resin.

To make a carbon-carbon composite, you impregnate the fiber with resin and then heat it until the resin converts to carbon. Then you repeat the process--more resin, more heating--until a solid matrix of carbon is formed.

I wonder how they make carbon-ceramic brake disks?

Sholin

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What else, '73 MB 280 SEL (Lt Blue)
Daily driver: '84 190D 2.2 5 spd.

Yes but I was trying to keep it simple which is why I said "think of...".

Ceramic composites start as composite of SiC with a random mix of carbon fibres (short) then the rotor is siliconized in a high-vacuum furnace. Siliconization is when the Si becomes like water and is absorbed like as sponge by the carbonized rotor.