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Ceramic Bonding

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Joints between ceramic and other materials as metals or glasses is strategic for those application where the coupling of dissimilar materials (ceramic and metals for example) is requested or when complicated shapes are needed. Ceramics can hardly be shaped in complicated shapes and this feature limits their potential applications. The bonding techniques offer the possibility to overcome this problem.

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The following bonds have been developed at ISTEC:

  • Bonding with glass interlayers of oxide systems (Al2O3, ZrO2 o composito Al2O3 – ZrO2)
  • Bonding with glass interlayers of non oxide systems (Si3N4 o SiC)
  • Direct bonding between oxide materials (Al2O3 – Al2O3 ZrO2- ZrO2)
  • Direct bonding between non oxide materials (SiC-SiC e Si3N4- Si3N4 ZrB2-SiC composites)
  • Brazing between ceramic and metals with interlayers containing an active element (ZrO2- steel)

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PUBLICATIONS:

 

L. Esposito, A. Bellosi, Joining ZrB2-SiC composites using glass interlayers (2005) Journal of Materials Science, 40 (17), pp. 4445-4453.

M.G. Faga, S. Guicciardi, L. Esposito, A. Bellosi, G. Pezzotti,Alumina/alumina and alumina-zirconia/alumina-zirconia joints through glass interlayers, microstructure, mechanical properties and residual stresses (2005) Advanced Engineering Materials, 7 (6), pp. 535-540.

L. Esposito, A. Bellosi, Ceramic oxide bonds using calcium aluminosilicate glasses (2005) Journal of Materials Science, 40 (9-10), pp. 2493-2498.

L. Esposito, A. Bellosi, Joining of ceramic oxides by liquid wetting and capillarity (2001) Scripta Materialia, 45 (7), pp. 759-766.

D. Sciti, A. Bellosi. L. Esposito, Bonding of zirconia to superalloy with the active brazing technique (2001) Journal of the European Ceramic Society, 21, pp. 45-52.

A. Bellosi, L. Esposito, Protective coatings for non-oxide ceramics (2000) Surface Engineering, 16 (5), pp. 397-402. 

L. Esposito, A. Bellosi, S. Landi, Interfacial forces in Si3N4- and SiC-based systems and their influence on the joining process (1999) Journal of the American Ceramic Society, 82 (12), pp. 3597-3604.

R.M. Cannon, L. Esposito, High temperature colloidal behavior: Particles in liquid silicates (1999) Zeitschrift fuer Metallkunde/Materials Research and Advanced Techniques, 90 (12), pp. 1002-1015.

L. Esposito, A. Bellosi, S. Guicciardi, G. De Portu, Solid state bonding of Al2O3 with Cu, Ni and Fe: Characteristics and properties (1998) Journal of Materials Science, 33 (7), pp. 1827-1836. 

L. Esposito, A. Bellosi, G. Celotti, Silicon nitride-nickel joints through diffusion bonding (1997) Acta Materialia, 45 (12), pp. 5087-5097.

PROCESSES & FACILITIES:

The bonding techniques for ceramic materials can be described as follows:

  • Bonding with glass interlayer’s. In this technique a thin glass interlayer is used, that when heated up to the melting temperature, bonds the two ceramic pieces. A great advantage of this technique is that no pressure is required and that pieces with complicated shapes or even with irregular surfaces can be bonded together. This technique has been optimized for oxide and non oxide ceramics with glasses that melt in a wide temperature range (1000-1500°C). The process in controlled by the wetting ability of the glass for the ceramic and by the chemical and physical compatibility among the involved phases and by the thermal cycle (bonding temperature, heating and cooling rate).
  • Direct joining and joining with metallic interlayers. In this case the bond in obtained by means of a pressure applied during the heating cycle. With this technique bonds with a mechanical resistance close to the one of the bulk ceramic can be realized.
  • Brazing between metals and ceramics with interlayer containing an active element. This technique allows the bonding between very dissimilar materials, as ceramics and steels, but requires the use of high vacuum clean atmosphere furnaces(carbon free)