Mechanism Study Of Si/Cu Coating By Composite Electro-brush Plating And Its Application

Composite electro-brush plating technology, as an important component of surface engineering, is an effective method of mechanical parts repair and strengthening. In the fields of size repairing, improvement of wear resistance and other mechanical properties of components surface, composite electro-brush plating has a wide range of applications. This kind of surface technology has a series of advantages such as handy equipment, flexible process, high bonding strength, wide range of applications, and so on. In the area of welding, contact nozzle is an important electro connecting component in the equipment of gas protect arc welding. The poor wearability of the nozzle has always been a problem, especially in the applications of mechanized and automatic welding, the service lifetime has the direct bearing on economic viability. In this paper, the main content of the study is preparing SiC/Cu composite coatings on the contact nozzle with high wear resistance by composite electro-brush plating.SiC/Cu composite coatings were prepared under different process condition by composite electro-brush plating. It can be concluded at the plating time of 20min, current density of 3A/dm2, voltage of 8V and 20g/L SiC, the plating layers are compact and homogeneous.Besides, wear test was designed to simulate the abrasive condition of contact nozzle and welding wire. The results show wear loss of SiC/Cu composite coatings was 27% below pure copper under the load of 0.5kg.Moreover, co-deposition mechanism was investigated according to the surface microstructure of composite coatings. It was found that there were three different patterns of SiC deposition in plating layers during electro-brush plating process, i.e. the particles could deposit inside copper grains, in grain boundaries, or in holes of the surface.SiC/Cu composite coatings were prepared on a contact nozzle. And it was found that the contact tip with plating layer has similar weldability with the normal tip, but the wear resistance is much better.