チタン箔によるフォルステライトセラミックとニッケルおよび鉄-ニッケル合金との封着

抄録

Forsterite ceramic-to-nickel and -to-Fe-Ni alloy seals were formed by a reactive alloying method utilizing titanium foil, and the seal strength was measured by tensile tests. Moreover, the interfaces between the materials were examined by optical microscopy, scanning electron microscopy, electron probe microanalysis and X-ray diffraction.
The best thermal treating condition is 1273 K as the heating temperature and 300-600 seconds as the holding time for this method. The highest seal strength was 5 MPa for the forsterite ceramic-to-nickel seal and 7 MPa for the forsterite ceramic-to-Fe-Ni alloy seal. The major part of the fractured surface in the samples sealed with the best condition was the ceramic itself. The lower the heating temperature and/or the shorter the holding time than these of the best condition, the more the separation was apt to take place at the interfaces between the titanium foil and the ceramic, while the higher the heating temperature and/or the longer the holding time, the larger the fractured surface at the interfaces between the titanium foil and the metal became.
Titanium diffused into the ceramic and metal, and the Ti-Ni binary alloy or the Ti-Ni-Fe ternary alloy was formed in the interfaces between the titanium foil and the metal. Titanium is considered to react with SiO₂ to form intermediate layers at the interfaces between the titanium foil and the ceramic.