A kind of preparation method of copper tungsten contact material

Abstract

The invention discloses a preparation method of a copper-tungsten contact material. The method comprises the steps of performing ball grinding on tungsten powder, high-purity nickel balls and water in a ball grinding machine, and performing drying, annealing, forming, pre-sintering and infiltration treatment on the tungsten powder subjected to ball grinding, wherein the weight ratio of the high-purity nickel balls to the tungsten powder is (4-10) to 1; the use amount of the water is calculated according to a fact that every 1kg of tungsten powder is added to 120-150ml of water; and the ball grinding is executed for 12-48 hours. By the adoption of the special ball grinding technology, adding of nickel and ball grinding are simultaneously executed; furthermore, the added nickel can uniformly cover the surface of the tungsten particles, so that the activated sintering effect of a tungsten framework is effectively enhanced, and a tungsten framework with high performance can be obtained; the copper-tungsten contact material prepared by performing infiltration treatment on the tungsten framework and a copper sheet has a tissue structure that the tungsten particles are uniformly distributed on a copper base body, so that the prepared contact material is perfect in arc erosion resistance and high in high-temperature mechanical strength.

Description

technical field [0001] The invention relates to a method for preparing a copper-tungsten contact material, belonging to the field of metal-based composite materials. Background technique [0002] Due to the high melting point of tungsten and strong arc erosion resistance, and copper has excellent electrical and thermal conductivity, copper tungsten materials have both good arc erosion resistance and electrical and thermal conductivity, so copper tungsten contact materials are widely used as arc contacts. Applied to SF 6 On the high-voltage circuit breaker, it plays the role of turning on and breaking the current. Because in the process of switching on and breaking the current, on the one hand, all the arcs generated are borne by the arc contacts, and the contacts are subject to arc erosion, high temperature and thermal stress; on the other hand, due to the mutual impact of the moving and static contacts The contact is also subject to mechanical stress, and the failure of t...

AI Technical Summary

Problems solved by technology

But there are following problems in this method: 1. the 0.05~0.15% trace activated sintering element nickel added is difficult to disperse uniformly in the process of mechanical mixing; During the mechanical mixing process, due to the hindrance of copper powder, the probability of tungsten particles capturing nickel is greatly reduced; ③After mechanical mixing, it is difficult to avoid the enrichment of copper

Therefore, during subsequent infiltration and sintering, the activated sintering effect of the tungsten skeleton will be greatly reduced, and the tungsten particles in contact with each other in the tungsten skeleton cannot be sintered into one, so the high-temperature mechanical strength of the prepared copper and tungsten will also be greatly reduced. The degree of dispersion is not high enough

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