Copper Electrode with Tungsten Coating by DC Plasma Spray (1/2)

Tungsten (W) has high hardness, high density and excellent wear resistance, while copper (Cu) has good thermal and electrical conductivity so that tungsten copper is one of the ideal materials in electrode. However, we should distinguish tungsten copper electrodes and copper electrodes with tungsten coating. In order to achieve the goal that the coating material on copper electrode has high melting point, good electrical conductivity, low absorption and coefficient of thermal expansion, we can only through DC plasma spray forming of tungsten coatings on the copper electrode. Tungsten coatings usually were develop for nuclear fusion devices, which should have the thickness of approximately 300μm, density more than 97% of the theoretical, purity above 99.9%, good toughness, high adhesion, smooth surface and clean coating / substrate interface.

DC (direct current) plasma has the characteristics of small plasma volume, high energy density, lateral injection of powders, high particle velocity, and short particle residence time. It has been used in industries for wear resistance coating, corrosion-resistant coating, thermal barrier coating and other coating depositing. Radio frequency induction plasma has the characteristics of large plasma volume, low energy density, central injection of powders, low particle velocity, long particle residence time, and the lack of electrode contamination. Induction plasma spraying, as a new technology, is being applied to melting, spheroidization and deposition of the refractory materials, such as tungsten (W), molybdenum (Mo), Aluminum oxide (Al2O3) as well as to the synthesis and processing of ceramic materials.

 

WeChat