Method for Joining Ceramics to Ceramics or Ceramics to Metals, and Apparatus

Abstract

An assembly including a ceramic body. The assembly comprises a tungsten coupling attached to the ceramic body with a first joint that forms a first helium tight seal between the ceramic body and the tungsten coupling and where the first helium tight seal maintains its integrity at a temperature over 400° C. The assembly includes a metal body attached to the tungsten coupling with a second joint that forms a second helium tight seal between the metal body and the tungsten coupling and where the second helium tight seal maintains its integrity at a temperature over 400° C. A method. A mixture. A coupling.

1 . A method of forming an assembly comprising the steps of:
 forming a first joint between a ceramic body and a tungsten coupling to create a healing first helium tight seal between the tungsten coupling and the ceramic body where the first helium tight seal maintains its integrity at a temperature over 1100° C.; and   forming a second joint between the tungsten coupling and a metal body to create a second helium tight seal between the tungsten coupling and the metal body where the second helium tight seal maintains its integrity at a temperature over 1100° C.   
     
     
         2 . An assembly comprising:
 a first ceramic body; and   a second ceramic body attached to the first ceramic body with a first joint that forms a first helium tight seal between the first ceramic body and the second ceramic body and where the first helium tight seal maintains its integrity at a temperature over 1100° C.   
     
     
         3 . The assembly of  claim 2  wherein the first ceramic body and the second ceramic body are hollow and form a continuous channel extending through and inside the first ceramic body and the second ceramic body and the first helium tight seal. 
     
     
         4 . The assembly of  claim 3  wherein the first ceramic body is made of silicon carbide and the second ceramic body is made of either silicon carbide or 3:2 mullite. 
     
     
         5 . The assembly of  claim 4  wherein the first joint is made of between 30 wt % (weight percent or percent by mass) and 80 wt %, nominally 60 wt %, alumina-silicate, and between 20 wt % and 70 wt %, magnesia-silicate. 
     
     
         6 . The assembly of  claim 4  wherein the first joint is made of between 16.8 wt % and 35.8 wt % alumina, between 57.9 wt % and 61.2 wt % silica and between 6.3 wt % and 22.0 wt % magnesia. 
     
     
         7 . The assembly of  claim 5  wherein the first ceramic body attached to the second ceramic body aligns to define a straight line. 
     
     
         8 . The assembly of  claim 7  wherein the first ceramic body attached to the second ceramic body defines a bend. 
     
     
         9 . The assembly of  claim 8  wherein the first ceramic body attached to the second ceramic body defines a manifold. 
     
     
         10 . A method of forming an assembly comprising the steps of:
 placing a first ceramic body adjacent a second ceramic body; and   forming a first joint between the first ceramic body and the second ceramic body to create a first helium tight seal between the first and second ceramic bodies where the first helium tight seal maintains its integrity at a temperature over 1100° C.   
     
     
         11 . A coupling comprising:
 a member made of tungsten having an inner surface about the hollow and an outer surface; and   a coating disposed on the outer surface in its entirety so no portion of any surface of the member is exposed, the coating made of an oxidation resistant material so the member maintains its integrity above 400 degrees C. and does not oxidize.   
     
     
         12 . A mixture for a joint between a metal body and a metal body comprising:
 between 10 wt %-80 wt % 80/20 nickel-chromium alloy powder, and 20 wt %-90 wt % copper wire or grain of ≥99.99% purity.