Ti effects on ceramic joining (esp. alumina) ? 1

[needy]

HELP !

I am desparately trying to understand the potential effects of Ti on the joining/brazing/sintering of alumina refractories. I have found out that Ti is often used as a constituent of active fillers for joining of ceramics to other ceramics, but dont know why or what effect the Ti would have on alumina ... any ideas/references ? Getting desparate, would be grateful for any help whatsoever.

Thanks in advance

 

[tomwalz]

We have proprietary technology in this area. Not sure if it applies in your application. Call me, Tom Walz, at 253 476 1338 and we can talk.

Tom

 

[birol]

This is not an answer to your question, but it is an alternative approach to active brazing. Ceramics can be joined by controlling CTE of join. We do this in our plant by using aluminum reinfoced composites. Depending your application we may want try this approach too. My phone # is 303 833 6140.

 

[birol]

This is not an answer to your question, but it is an alternative approach to active brazing. Ceramics can be joined by controlling CTE of join. We do this in our plant by using aluminum reinfoced composites. Depending your application we may want try this approach too. My phone # is 303 833 6140.

 

[CadAndy]

Go to a serch engine and type patents
then search the patent database for Titanium
brazing.

We brazed titanium to alumina and beryllium.
The main reason was for thermal expansion and
compatiblity with ohter materials.

All are brazing was vacuum brazing with
35/65 Gold Copper or Cusil depending on
mating materials.

The Patent Web Site should help out also

Andy Kaczmarek

 

[tomwalz]

Titanium can be really wettable. If you put titanium in an active braze alloy it wets well and helps the bonding to the Alumina. If you take Alumina and add a little Titanium in any form (TiC) you can braze it with a standard BAg (silver based with usually copper, zinc and maybe nickel and / or manganese) alloy. You can get a tensile strength of 80,000 psi. and a braze joint good to 1300 F with an alloy that costs about $5.00 an ounce. You can do it with any brazing method including a torch and flux.

Some things wet better than others. Steel wets well once you remove the scale. You can get some materials to wet well if you remove the oxide layer. The trick is to keep the oxide layer from reforming. Some times you can braze successfully to just part of the material. You can braze tungsten carbide in a cobalt matrix by just brazing to the matrix.

See U.S. patent 6,322,871 and / or

http://www.carbideprocessors.com

Tom Walz