Compared with silver-copper composite rivets and tungsten-iron composite rivets, more and more customers have begun to choose copper-tungsten composite rivets in recent years. Tungsten is more wear-resistant and has better resistance to arc erosion; copper has better conductivity than iron rivets; and copper is much cheaper than silver, which can save a lot of costs.

However, there are many difficulties in the production of copper-tungsten rivets:

1.Difficult to weld, low welding strength. Tungsten sheets and copper nails can only be produced by welding, but the melting points of copper and tungsten are very different. The melting point of copper is low, while the melting point of tungsten is as high as thousands of degrees Celsius. This leads to the need for special heating methods and equipment during the welding process to ensure that the two materials can melt at the same time and form a good welding joint.

Secondly, the thermal expansion coefficients of copper and tungsten are different, and thermal stress concentration and deformation are prone to occur after welding. This requires the welding process to accurately control the heating speed and cooling speed to reduce the impact of thermal stress.

Due to the poor compatibility between copper and tungsten themselves, if the technology is not in place, defects such as cracks and pores are prone to occur.

2.Solder overflow. In order to ensure welding strength, manufacturers generally increase the amount of solder used, which can easily cause solder overflow and generate sparks during use. After the process improvement of SHZHJ, there is basically no solder overflow in small-diameter copper-tungsten rivets; the proportion of solder overflow in large-diameter copper-tungsten rivets is greatly reduced.

3.Incomplete welding. There is a gap at the edge or in the middle between the tungsten layer and the copper rivet, and there is no solder. This situation is common in manual welding. To solve this problem, more solder is usually added, but it is also more likely to cause solder overflow. To solve this problem, for large-volume orders, SHZHJ supports customized automated production lines to make welding more uniform.

4.Electroplating is difficult. Contacts are often required to be silver-plated. However, an oxide layer is easily formed on the surface of tungsten, which will affect the adhesion of the silver plating. The electroplating technology exclusively developed by SHZHJ can improve the yield rate of silver-plated copper tungsten rivets. Although the price is a little higher than that of ordinary pure copper silver plating, it is still favorable compared with other countries and regions, and the quality of the finished products is strictly guaranteed.