Skip to main content
eScholarship
Open Access Publications from the University of California

UC Davis

UC Davis Previously Published Works bannerUC Davis

Bonding of Silicon Nitride Using a Preceramic Polymer and Germanium Powders with a Potential Fuel Cell Applications

Abstract

A new method for bonding blocks of Si3N4 has been developed that produces bonds whose maximum service temperature is equal to the temperature used during the bonding process. In this work a system consisting of the blocks of Si3N4, which had been coated with a preceramic film containing a fine dispersion of silicon and a thin layer of germanium powder, were investigated to determine the effect of the thickness of the germanium film. The maximum service temperature is not determined by the melting point of the germanium since the germanium forms a higher melting point solid solution with the silicon in the film. Control of the thickness of the germanium film is critical as it was shown that thicker layers result in lower strength bonds due to differences in thermal expansion and the maximum service temperature is lower due to the lower liquidus temperature of the leaner Ge-Si solid solution. This technique has potential applications in fuel cells due to the small differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials, thus allowing successful fabrication and joining process of the monolithic solid oxide fuel cell (MSOFC) with few defects.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View