abstract
As the voltage level and current of high-voltage switch products continue to increase, more and higher requirements are put forward for the core components of switch products, copper tungsten contacts. The following will introduce a new production method for the contact.
method for preparing a copper-tungsten contact
A method for preparing a copper-tungsten contact, that is, the tungsten skeleton is pressed in sections in the height direction, and the activation element is evenly coated on the interface of the tungsten skeleton before sintering, and then the tungsten skeleton is prepared by an overall sintering method.
The method includes the following steps: the contact tungsten skeleton is divided into several parts according to height in the vertical direction, and the sections are pressed, after the pressing is completed, an appropriate amount of activation element is evenly coated on the contact surface of the alloy blank, and each blank is stacked in a crucible in sequence, and an appropriate amount of copper blocks are placed around the blank; the crucible is placed in a sintering furnace, and a copper-tungsten alloy contact blank is obtained by sintering according to certain process parameters, and finally the finished part is obtained by processing according to the size.
The precautions of this technology are as follows:
(1) the activator is nickel powder.
(2) the mass of the activator coated per unit area is less than 1% of tungsten.
advantage of this technology
The advantage of this technology is that it solves the problem of preparing copper-tungsten skeletons with a large height-to-diameter ratio, greatly improves the utilization rate of raw materials of such parts, and solves the limitation that molding cannot be used in the preparation process of contact skeletons of such structures.
It is reported that the production of trumpet-shaped contacts cannot be achieved by traditional molding methods; and if the contacts with larger diameters are directly pressed by molding, the density of the tungsten skeleton inside and outside and in different parts of the upper and lower parts will be different. At the same time, it is also difficult to evenly infiltrate the copper liquid during the infiltration stage, which makes it impossible to guarantee the use of the contacts. In addition, even if the cylindrical skeleton is directly pressed by molding, and the trumpet-shaped structure is obtained by machining, there will be a great waste of raw materials and machining.