ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract In bonding ceramic oxides to metals, two reaction mechanisms have been utilized. These are (1) a surface or microscopic reaction, between close-packed ceramic oxides, quartz, and glasses and the noble metals (e.g. Pt, Pd, Au, Ag), maintaining a sharp discontinuity at the interface, (2) a bulk or macroscopic reaction between the same oxides and other transition metals (e.g. Fe, Co, Ni) producing a diffusional type interface. Both have common reaction conditions and occur: (a) below the melting point of the lowest melting component, (b) in any atmosphere compatible with all components at the operating temperature, (c) under little or no pressure, and (d) without deformation. The progress of several Type 1 reactions has been followed by direct observation at elevated temperatures and high resolution in a modified transmission electron microscope. It has thereby been established that this reaction proceeds with the formation of an intermediate phase, liquid-like at temperatures below the melting point of any of the components. Bonds have also been examined using electron scanning microscopy, electron probe microanalysis, and optical microscopy. Vacuum tight bonds can be produced and shear tests indicate that strength is generally limited by the strength of oxide components.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00550438
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