LOW-TEMPERATURE REFRACTORY METAL-TO -CERAMIC SEALS.
Abstract
The report covers a two-year study on low-temperature refractory metal-to-ceramic seals. The development phase was concerned with: the effect of process variables; effects of ball milling on particle size and seal strength; effects of changes in Mn concentration and the effects of compositional changes in the W, Mn, Fe metalizing system. Low-temperature mixes were adapted to silk screen and transfer tape metalizing techniques. Seal reliability was studied through heat cycling experiments. Numerous suspension mixes as well as metalizing solutions were investigated. The low-temperature process was found satisfactory on various alumina and beryllia bodies. Solution metalizing investigations were concerned with: concentration of salts; thickening agents and solution stability. Feasibility of the low-temperature process was demonstrated by the fabrication of a number of hermetic seals used in production tubes. A comparison of low-temperature metalizing with conventional Mo/Mn metalizing process is presented. A theoretical phase involved: electron probe analysis of low-temperature metal-ceramic interface; X-ray diffraction techniques to detect compounds formed at the interface; various experiments designed to synthesize compounds formed at the interface, and micrographic and electron microscope techniques to detect internal microstructural changes that occur in a ceramic during heat cycling. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1966
- Accession Number
- AD0632362
Entities
People
- J. Michael White
- L. A. Tentarelli
- R. W. Buck