CS199807B1 - Galvanic unit from solid electrolyte for measurement of oxygen content in metallic liquid alloys - Google Patents

Description

(54) Solid electrolyte galvanic unit for measurement containing oxygen in metal _x flux

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a solid electrolyte galvanic unit for measuring the oxygen content of a metal melt comprising a specific electrode in contact with a metal melt and a reference system separated by a solid electrolyte from a metal melt with a reference electrode. soldered in a hole in the wall of a metal hollow body of nickel or of nickel or iron alloys, corrosion-resistant and heat-resistant and introduced into the metal melt according to the author's certificate no.

174 909.

It is an object of the present invention to provide an improved embodiment of the solid electrolyte galvanic unit according to the present invention, wherein the solder zone between the hollow body and the solid electrolyte or between the hollow body and the solderable solder layer deposited on the solid electrolyte is at least trace amounts of one metal of the group consisting of gallium, indium, thallium, germanium, antimony and zinc with iron and / or nickel, the maximum of which these metals, when used alone in solder, are 28% atomic for gallium, 2,6% atomic for indium ,

1.3% atomic for thallium, 9.1% atomic for germanium, 7.0% atomic for indium, and 26.4% atomic for zinc, and the maximum proportion of the mixture of these metals in the solder generally corresponds to the maximum proportion of the worst soluble metal contained in mixtures when used alone.

199 807

199 807

According to a preferred embodiment of the invention, the brazing zone is characterized in particular by the fact that the solder zone has similar physical and soft properties to the metal hollow body. This simplifies the assembly of suitable pairs of materials for solid electrolyte and hollow body and allows tightly sealed connections with high durability.

The invention is explained below by way of example with respect to the connection of a solid electrolyte of thorium oxide and yttrium oxide in a tablet shape, with a solder and one end of a tubular nickel-iron hollow body.

The pre-treated solid electrolyte is either metallised or coated with a pallet of active materials such as titanium, zirconium or thorium, and a metal hydride such as titanium hydride or zirconium hydride, or an organic binder and solvent to be introduced into the tubular tubular hollow body. gaps between the hollow body and the solid electrolyte and apply as a solder a paste made by spreading liquid gallium and nickel powder containing about 25% atomic gallium · The brazing assembly is subsequently heated under vacuum or preferably under shielding gas. for a few minutes so that the conoentraoe in the liquid phase can equalize · Then the temperature is quickly reduced by 60 to 100 ° C, so that the liquid solder cannot divide according to the solid state curve of the state diagram. at m soft annealing of an iron-nickel alloy to achieve connections that have less meobanic stresses ·

Alloys of nickel, iron or their alloys may also be used in place of solder alloys of pure gallium, indium etc. · and nickel, iron or its alloys ·

For example, a comminuted mixture consisting of 5.2 g of gallium and 3.5 g of germanium and 53.4 g of nickel powder · This pájeoi powder contains then 4.55% atomic gallium and 4.55% atomic germanium. and therefore germanium does not exceed the maximum permissible proportion of the less soluble component in nickel, i.e. germanium, which is 9.1% atomic by the use of germanium alone, as mentioned above.

This solder is applied to the brazing site as explained above, with a brazing temperature equal to about 300 ° C. Cooling and then also carried out as described above.

In the same way, it is possible to form a solder position of the alloys which, while keeping the above-mentioned maximum proportions of the individual components, ensure that the solder region is in the alpha phase. The above-mentioned paddles in atomic% correspond directly to the degree of solubility of the individual metals, of which the gallium represents the best and thallium the worst soluble metal ·

Claims (2)

SUBJECT OF THE INVENTION 1 · A solid electrolyte galvanic unit for measuring the oxygen content of a metal melt, consisting of a specific electrode in contact with a β metal melt and a reference system separated by a solid electrolyte from a metal melt, a β reference electrode, the solid electrolyte being tightly soldered in a hole in the wall of a metal hollow body of nickel or nickel or iron alloys, corrosion resistant and heat resistant and introduced into the metal melt, characterized in that the solder zone between the hollow body and the solderable layer deposited on the solid electrolyte an amount of one metal selected from the group consisting of gallium, indium, thallium, germanium, antimony and zinc with iron and / or nickel, the maximum proportion of these metals when used alone in the solder is 28% atomic for gallium, 2.6% atomic for indium , 1.3% atomic for thallium, 9.1% atomic for germanium, 7.0 % atomic for Indium and 26.4 atomic zinc, and the maximum proportion of the mixture of these metals in the solder / generally corresponds to the maximum proportion of the worst soluble metal contained in the mixture when used alone. Galvanic unit according to claim 1, characterized in that the solder alloy is in the alpha-phase