9 replies to this topic

[theo_dragonas]

Hello all of you! I have heard that nowadays F1 pistons are made of ceramic materials. I believe the material to be a metal matrix composite, with an Al matrix and a ceramic reinforcement. These have been used in passenger vehicle engines. The reinforcement would be SiC or Al2O3. Any ideas on that?

[Group B]

I have a feeling that ceramics and offer exotics are banned in F1 engines (shame ) but I'm not at all certain so I'll leave it to one of the regular techsperts here to show up and confirm it.

[theo_dragonas]

The new regulation says that any material with young's modulus bigger than 40 GPa is banned. There is no ban about especially a material or a group of materials. This regulation was to ban the health hazardous (or very expensive?) Beryllium used by Illmor and Cosworth.

[Top Fuel F1]

Originally posted by theo_dragonas
Hello all of you! I have heard that nowadays F1 pistons are made of ceramic materials. I believe the material to be a metal matrix composite, with an Al matrix and a ceramic reinforcement. These have been used in passenger vehicle engines. The reinforcement would be SiC or Al2O3. Any ideas on that?

In F1 when you hear something is made of Ceramic what they are really talking about are Ceramic coatings such as Nikasil on an Al Alloy part such as a piston or a cylinder wall (sleeved or sleeveless).

MMC pistons would be legal in F1 and who knows when some teams will start using them. Although they have been used in some cars already one principal F1 engine builder said about a year ago that for some reason he did not considered them ready for Prime Time in F1. Who knows that may have changed by now.

Also you can look at www.fia.com at the F1 Tech. Rules to get info on some other materials that are currently not allowed in pistons.

Rgds;

[VAR1016]

Originally posted by theo_dragonas
The new regulation says that any material with young's modulus bigger than 40 GPa is banned. There is no ban about especially a material or a group of materials. This regulation was to ban the health hazardous (or very expensive?) Beryllium used by Illmor and Cosworth.

Probably a bit of both. Beryllium is doubtless very costly, but then have a look at that cast titanium Ferrari crankcase that featured in a post recently - that can hardly have been cheap!

Beryllium dust is highly carcinogenic. Interestingly I understand that Porsche used the material for brake discs in the 1960s!

VAR1016

[Top Fuel F1]

Also take a look at:

http://www.atlasf1.c...&threadid=46802

[desmo]

15.1.2 No parts of the car may be made from metallic materials which have a specific modulus of elasticity greater than 40 Gpa(g/cc).

Note that this applies only to metallic materials. IMO any ceramic reinforced MMC whose matrix is within the modulus limit is hence legal for engine internals, even if the part in toto exceeds the limit. Additionally CF and aramid reiforcements are illegal for internal engine parts. This ban has IMO little or no effect on the choices of materials used.

My assumption therefore is that in order to be competitive, MMC pistons- likely with sophisticated preforms within the matrix exhibiting significant anisotropic properties- are now necessary to be competitive. Expect the alloy matrix to be right at the modulus limit. These may be functionally superior to the now banned Be alloy ones- and a lot more expensive!

[Top Fuel F1]

Originally posted by desmo
15.1.2
My assumption therefore is that in order to be competitive, MMC pistons- likely with sophisticated preforms within the matrix exhibiting significant anisotropic properties- are now necessary to be competitive. Expect the alloy matrix to be right at the modulus limit.

desmo:

Any idea why the physics of this would call for anisotropic properties (having the same properties in one direction, such as elasticity) as opposed to isotropic (having the same properties in all directions)? As well (if anisotropic) would the stiffest value be from the top to the bottom of the piston for instance?


Rgds;

[desmo]

Many stresses on a piston are highly directional. At the same time the shape is largely determined by design constraints imposed by the geometry of its mechanical environment. The result is a design in isotropic material will by necessity have more material in places than structurally required. Cleverly designed high modulus anisotropic preform reinforcements can reduce the design compromise and thus in turn reduce the total mass of the piece. A reduction in weight of even a single gram for a piston can yield measurable improvements in max rpm and thus power. One well known engine guru has I'm told stated that a 10g reduction in the piston set for a V10 could be worth 10bhp in top end. Obvious places to reinforce would likely be in the crown, the load paths between the crown and the bosses for the piston pin, and the ring land areas.

[Top Fuel F1]

desmo: O.K. Makes sense! Thanks.