| 摘要 |
A ceramic such as a high purity alumina is coated with a sintered layer containing a high melting point metal such as Pt, Mo, W, Nb or Ta by applying a powdered mixture of the metal and an additive consisting mainly of CaO, or a mixture of CaO with Al2O3 and/or SiO2, or a compound of CaO with one or more of these oxides, or a mixture of two or more of said compounds or a mixture of one or more of said compounds and one or more of CaO, Al2O3 and SiO2, the molar ratio of Al2O3:CaO being less than 2.25 and the molar ratio (Al2O3 + CaO):SiO2 being greater than 0.35 in said additive. The additive may also contain up to 25% by weight of oxides such as those of the alkali metals, e.g. Na, other alkaline earth metals Mg, Sr or Ba, and B, Ti, Mn or Zn. The powder mixture is applied to the ceramic with a binder such as nitrocellulose solution and sintered in hydrogen, nitrogen and hydrogen or air at 1200-1600 DEG C. Ceramics such as UO2, ZrO2, BeO, MgO, MgO.SiO2, MgO.Al2O3, aluminates, zirconates, titanates and ferrites may be metallized. The metallized ceramic may be bonded to metal articles such as Mo, W, Nb, Ta, Pt and ferrics by soldering using a solder such as an alloy consisting of 70% Au, 16% Cu, 14% Ni.
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