Process for forming unusually strong joints between metals and ceramics by brazing at temperatures that do no exceed 750 degree C.

Patent · Wed Jan 01 00:00:00 EST 1986

OSTI ID:866047

Hammond, Joseph P ^[1]; David, Stan A ^[1]; Woodhouse, John J ^[2]

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1. Knoxville, TN
2. Crossville, TN

This invention is a process for joining metals to ceramics to form very strong bonds using low brazing temperature, i.e., less than 750.degree. C., and particularly for joining nodular cast iron to partially stabilized zirconia. The process provides that the ceramic be coated with an active metal, such as titanium, that can form an intermetallic with a low melting point brazing alloy such as 60Ag-30Cu-10Sn. The nodular cast iron is coated with a noncarbon containing metal, such as copper, to prevent carbon in the nodular cast iron from dissolving in the brazing alloy. These coated surfaces can be brazed together with the brazing alloy between at less than 750.degree. C. to form a very strong joint. An even stronger bond can be formed if a transition piece is used between the metal and ceramic. It is preferred for the transition piece to have a coefficient of thermal compatible with the coefficient of thermal expansion of the ceramic, such as titanium.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4621761
• OSTI ID: 866047
• Country of Publication: United States
• Language: English

Related Subjects

process
forming
unusually
strong
joints
metals
ceramics
brazing
temperatures
exceed
750
degree
joining
form
bonds
temperature
particularly
nodular
cast
iron
partially
stabilized
zirconia
provides
ceramic
coated
active
metal
titanium
intermetallic
melting
alloy
60ag-30cu-10sn
noncarbon
containing
copper
prevent
carbon
dissolving
surfaces
brazed
joint
stronger
bond
formed
transition
piece
preferred
coefficient
thermal
compatible
expansion
strong bond
process provides
cast iron
coated surface
active metal
thermal expansion
carbon containing
stabilized zirconia
containing metal
partially stabilized
brazing alloy
strong joints
strong bonds
joining metal
strong joint
brazing temperature
/228/