A kind of preparation method of silver sheet for fuse

Abstract

A silver strip for a fuse protector comprises a silver alloy on the outer layer and pure silver at the core part, and the silver alloy is silver-copper alloy powder formed through mixing of the components, by mass ratio, of 0%-10% of CdO powder and 0%-2.5% of Ni powder and the balance of 70%-75% of Ag and 25%-30% of Cu; the preparation method comprises the following steps: the raw materials are weighed according to the mass ratio and loaded into a ball mill for high energy ball milling; the uniformly ball-milled raw material fine powder is put into an annular steel mold, and a hollow blank isformed through suppressing of an isostatic press; the pure silver is taken and smelted by vacuum smelting equipment, and a silver ingot is casted in the mold; the silver ingot and the hollow blank areassembled and placed into a vacuum sintering furnace for reaction and burning into a billet, then the round billet is squeezed into a sheet blank, the sheet blank is subjected to multi-pass rolling,and the smelted silver strip with self-arc-extinguishing capacity can be prepared; the silver strip for the fuse protector has excellent electrical conductivity, self-arc-extinguishing capacity, suitable smelting point and excellent processability.

Description

technical field [0001] The invention relates to the field of electrical engineering, in particular to a method for preparing a silver sheet for a fuse with self-extinguishing arc capability. Background technique [0002] The fuse is a kind of current protector made according to the principle of breaking the circuit by melting the melt with the heat generated by itself after the current exceeds the specified value for a certain period of time. Fuses are widely used in low-voltage power distribution systems, control systems, and electrical equipment. As short-circuit and over-current protection, fuses are one of the most commonly used protection devices. The fuse is mainly composed of two parts, the melt and the fuse tube, as well as additional fillers. When in use, connect the fuse in series in the protected circuit. When the current of the protected circuit exceeds the specified value, and after a certain period of time, the heat generated by the melt itself will fuse the f...

AI Technical Summary

Problems solved by technology

[0003] Because silver has many excellent properties, it has always been the best choice of melt material, but in the long-term use process, it is found that pure silver still has many problems as a melt material

On the one hand, the price of pure silver is high, which keeps the cost of electrical products high, and a large amount of precious metal silver is used to cause a waste of resources; Arc medium, the arc extinguishing capacity of the fuse is its main technical index. The rated voltage and rated current marked on the fuse actually refer to the arc extinguishing capacity of the fuse. If the melt is blown, the arc extinguishing medium is filled outside The arc cannot be extinguished in time due to failure or abnormality, and the short-circuit current may continue to form a loop through the arc, which will cause fire and explosion in severe cases; at the same time, pure silver has a high melting point as a melt material, and the temperature rises when the current is overloaded. To achieve circuit overload protection

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