Steve, That statement is incorrect. CERMET is the name given to several= =20 types of ceramic metal matrix. My father was a specialist in ceramics=20= and=20 ceramic-metalizing so I saw many trade types of cermet products. The idea of= =20 this matrix is that the metal stabilizes the compound to make the ceramic le= ss=20 prone to fracture. I believe an entire sideplate could be made of this mater= ial,=20 but it would be costly. Due to surrface hardness it must usually be diamond=20 ground. The article speaks of "spraying" the material. This would only be=20 possible with plasma spraying, and woould be very propriatiry since the cera= mic=20 portion of the matrix wouldn't melt unless they sprayed at more than 3000=20 degrees! Honda made cylinder barrels for the RC45 V-4 750 from cermet. Cerme= t is=20 supposed to be about the same weight as aluminum, but has a very hard surfac= e=20 after being finish ground. Most materials I have seen list a Coeficient = ;of=20 linear expansion at around 1.5 x 10^ -6 (one po= int=20 five times ten to the minus sixth) units per degree F. Aluminum Co= LE=20 is about 2 x 10^ -5 there is a lot of built up stress at the skin of a coati= ng=20 with tht much of a difference in expansion. If they guys doing the rotor=20 housings are doing a type of chrome and calling the result cermet then they=20= are=20 being misleading.

Bill Jepson

In a message dated 10/22/2007 7:48:15 PM Pacific Standard Time,=20 steve@stevet.net writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Not sure=20 what you're looking at, but the coating is called "Cermet" not ceramic.&nb= sp;=20 They also sell ceramic seals. Cermet is a brand name for a particula= r=20 kind of chrome plating, I believe.

Best Regards,

Steve

____________________________________________________________________<= /DIV>

On Oct 22, 2007, at 1:09 PM, wrjjrs@aol.com wrote:

Guys,

The real question is, does the coating stay on?! There are many typ= es=20 of coatings, the toughest coating won't help if it cracks or flakes off.= =20 Ceramic is one of the hardest materials around short of diamond. T= here=20 is no question that it will help lower sliding friction, do they have an= y=20 high time engines? This comes from someone who really likes coatings. If= the=20 coating flakes off the flakes themselves are the worse than anything you= =20 could put in there.
Bill=20 Jepson

See what's new= at AOL.com an= d Make AOL Your Homepage.

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