Investigation of tungsten dc vacuum arc characteristics. Technological application

The paper presents the results of investigation of legitimacies of generation of W vacuum arc plasma in dc mode and their application for deposition of coatings with high adhesion strength. The developed construction of the vacuum arc evaporator (VAE) ensures dc mode of W plasma generation in the current range of 350 A-750 A at arc voltage drop of more than 40 V. It is shown that at discharge current of 750 A W coating deposition rate can achieve 80 μm/h, which offers attractive perspectives for a number of technological applications of W plasma. We also investigated some legitimacies of changes in element composition, adhesion strength, hardness, morphology and structure of W coatings formed from plasma of a dc vacuum arc discharge (VAD) depending on regimes of coating deposition. It is shown that use of Ti plasma for creating a thick transition and damping layer under the regime of plasma immersion ion implantation and coating deposition under intensive ion mixing allows to increase adhesion strength of W coatings by several times.