8.2 Methods
Joining subcomponents by geometrical
interlock prior to sintering in the green or white-ware
assumes that the they are made of similar ceramics,
and that joining proceeds via material bonding processes
(slip jointing and laminating) during manufacture. (Cf.
Modular construction, p. 192)
Material bonding techniques belong to technically established
processes such as:
-
gluing with thermoplastics, elastoplastics
and thermosetting plastics (fixing wear-protection
plates)
-
soldering with metallic solders
(soldering in ceramic substrate and packaging technologies,
soldering pins on substrates, solder joints on rectifiers
and thyristor packages and surge arresters, wear-plates
on rocker arms in automobile motors, etc.) and glass
soldering or
- glued joints using ceramic adhesives.
This means that the most important
goals and areas of work are:
- adapting the glues and solders,
- matching the joining and application temperatures
and
- reducing internal stresses in the composite.
After firing the ceramic, bonding techniques based
on its interlock or friction include:
- shrink-fitting (slip-ring seals, pressing tools,
etc.),
- press-fitting,
- casting-in and filling (port liners, ceramic piston
lids, fasteners for insulators, etc),
- crimping / rolling,
- clamping (fastening burner tubes, fixing and sealing
heat exchangers, fastening cutting plates on lathe
or machining tools, etc.),
- push-fitting (e.g. bayonet joints),
- riveting / swaging and
- bolting (attachment of burner tubes, fastening
and sealing of heat exchangers, fastening cutting
plates on lathe or machining tools, etc)
and may require the development of specially adapted
joining elements.
| Joining
method
|
Material combinations
Ceramic with
|
Demount-able |
Ceramic
materials
|
| |
Ceramic |
Metal |
Plastic |
|
|
|
Cementing |
+
|
+
|
|
no
|
all
|
|
Gluing |
+
|
+
|
+
|
no
|
all
|
|
Soldering /
brazing after
metallisation
|
|
+
|
|
partial
|
all
|
|
Active solder bonding |
|
+
|
|
no
|
all
|
|
Soldering /
brazing with
sealing glass
|
+ |
|
|
no |
all
|
|
Screwing /
bolting
|
+
|
+
|
+
|
yes
|
all
|
|
Plug-in jointing |
|
+
|
+
|
yes
|
all
|
|
Clamping |
|
+
|
|
yes
|
all
|
|
Snap
connections
|
|
+
|
+
|
yes
|
all
|
|
Slip jointing /
laminating
|
+
|
|
|
no
|
all
|
|
Fill casting /
casting in
|
|
+ |
+
|
no
|
limited |
|
Crimping /
rolling
|
|
+
|
|
no
|
all
|
|
Pressing /
shrink fitting
|
|
+ |
|
partial
|
all
|
|
Vulcanising
|
|
+
|
|
no
|
all
|
Table 25: Joining
techniques for ceramic components: ‘+‘ =
feasible
| Jointing
method |
Active ceramic surfaces |
Joining method |
| |
Preferred
geometry
|
Hard
machining
|
Additions |
Conditions |
|
Cementing |
- |
- |
Sulphate
cement, lead alloys, putty / cements |
- |
|
Gluing |
-
|
Contact
areas
|
Klebstoffe
(or Glues (organic and/or inorganic) |
Hardening
temperature;
pressure
|
|
Soldering /
brazing after
metallisation
|
-
|
Contact
areas
|
a) Soft solders
b) Hard solders
|
a) 200–300 °C
b) 500–1,000 °C
|
|
Active solder bonding |
- |
Contact
areas
|
Active
brazes e.g. Ti, Cu sometimes as multi-layer
|
Special
atmosphere
600–1,130 °C
|
|
Soldering /
brazing with
sealing glass
|
- |
Contact
areas
|
Sealing
glasses |
450–1,600
°C,
sometimes with ad. pressure and sp. atmosphere
|
|
Screwing /
bolting
|
Fill-cast or glued-in thread or through-thickness
joint |
Contact
areas
|
Screw,
washer,
nut
|
Intermediate layer |
|
Plug-in jointing |
Rotational symmetry |
Contact
areas
|
-
|
-
|
|
Clamping |
Planar
or rotational symmetry |
Contact
areas
|
Fasteners |
Elastic
and/or
plastic inter-mediate layer
|
|
Snap
connections
|
Planar or rota-tional symmetry |
-
|
-
|
-
|
|
Slip jointing /
laminating
|
-
|
-
|
Identical ceramic slip |
Sintering,
pressure
|
|
Fill casting /
casting in
|
Hollow
bodies, rounds or oval |
- |
- |
Preheating,
very few materials suitable |
|
Crimping /
rolling
|
Planar
or
rotational symmetry
|
Contact
areas
|
- |
- |
|
Pressing /
shrink fitting
|
Rotational
sym-metry, external metal part
|
Joint
surfaces
|
- |
Pressing
force /
heating
|
|
Vulcanising
|
-
|
-
|
Rubber |
-
|
Table 26: Brief summary
of the characteristics of joining methods
|
|
