Paul, The CLE of pure Ti is 4.9 x 10-6th/deg F.

BTW Paul Ti-6al-4v is the most common alloy with a bit higher 
expansion rate. I incorrectly read the expansion rate the 
first time converting from micromillimeters/deg C etc sorry.
Bill Jepson

That is what I suspected. A solid silicon nitride ceramic insert 
would be ideal. Hard, very smooth  and no expansion to speak of. Don't know
what the thermal conductivity would be. The cost would be astronomical
I am sure. Same stuff super high speed ball bearings and apex seals 
are made of.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.