The effects of electro-deposition current parameters on performance of tungsten coating

Abstract

Tungsten coatings prepared on heat sink materials (Al2O3–Cu) as PFC not only can release amount of impinging thermal power but also can resist erosion under plasma particles bombardment in the ITER reactor. Therefore electro-deposition technique using for obtaining tungsten coating on Al2O3–Cu substrate was a novel technique especially for fusion applications. In this paper, pure tungsten coatings were successfully deposited under various pulsed current densities at 1173K in Na2WO4–WO3 melts. Furthermore pulse current density, duty cycle and period were investigated respectively so as to obtain well defined structures for tungsten coatings. The composition, crystal structure and microstructure of tungsten coatings were characterized by XPS, SEM and XRD techniques. The results indicated that pulsed current density, duty cycle and period have significant influence on tungsten nucleation and electro-crystallization phenomena.