Coating system to permit direct brazing of ceramics

Patent · Wed Jan 01 00:00:00 EST 2003

OSTI ID:875085

Cadden, Charles H ^[1]; Hosking, F Michael ^[2]

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1. Danville, CA
2. Albuquerque, NM

This invention relates to a method for preparing the surface of a ceramic component that enables direct brazing using a non-active braze alloy. The present invention also relates to a method for directly brazing a ceramic component to a ceramic or metal member using this method of surface preparation, and to articles produced by using this brazing method. The ceramic can be high purity alumina. The method comprises applying a first coating of a silicon-bearing oxide material (e.g. silicon dioxide or mullite (3Al.sub.2 O.sub.3.2SiO.sub.2) to the ceramic. Next, a thin coating of active metal (e.g. Ti or V) is applied. Finally, a thicker coating of a non-active metal (e.g. Au or Cu) is applied. The coatings can be applied by physical vapor deposition (PVD). Alternatively, the active and non-active metals can be co-deposited (e.g. by sputtering a target made of mullite). After all of the coatings have been applied, the ceramic can be fired at a high temperature in a non-oxidizing environment to promote diffusion, and to enhance bonding of the coatings to the substrate. After firing, the metallized ceramic component can be brazed to other components using a conventional non-active braze alloy. Alternatively, the firing and brazing steps can be combined into a single step. This process can replace the need to perform a "moly-manganese" metallization step.

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• DOE Contract Number: AC04-94AL85000
• Assignee: Sandia Corporation (Albuquerque, NM)
• Patent Number(s): US 6528123
• OSTI ID: 875085
• Country of Publication: United States
• Language: English

Related Subjects

coating
permit
direct
brazing
ceramics
relates
method
preparing
surface
ceramic
component
enables
non-active
braze
alloy
directly
metal
preparation
articles
produced
purity
alumina
applying
silicon-bearing
oxide
material
silicon
dioxide
mullite
3alsub2
osub32siosub2
active
applied
finally
thicker
coatings
physical
vapor
deposition
pvd
alternatively
metals
co-deposited
sputtering
target
fired
temperature
non-oxidizing
environment
promote
diffusion
enhance
bonding
substrate
firing
metallized
brazed
components
conventional
steps
combined
single
step
process
replace
perform
moly-manganese
metallization
vapor deposition
active metal
braze alloy
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