Brevier Technical Ceramics

 

      Verbindungs- und Fügetechnik

 

 


   

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

 

 

 
 
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