Deposition of W/a-C:H:Zr and W/a-C:H:W multilayer coatings on substrate made of porous graphite by arc – Electron beam hybrid method

• We prepared W/a-C:H:Me coating on graphite substrate by arc and electron beam physical vapour deposition technique.
• The DLC layer was formed only in presence of Zr.
• The advantages of a-C:H:Zr coating are lack of porosity, high hardness, and lack of wettability by liquid copper.
• The use of a-C:H:Zr coating for protection of industrial graphite moulds can give satisfactory results.

The W/a-C:H:Zr and W/a-C:H:W multilayer coatings were prepared on a porous graphite substrate by hybrid method combines of arc evaporation and electron beam evaporation processes (Arc-EB). The tungsten interlayer was deposited first to enhance coating adhesion. Phase composition of coatings was examined by Raman spectroscopy and X-ray diffraction. The measurement of hardness and Young's modulus has indicated a significant increase in mechanical properties after the deposition of upper layer. Microstructure was investigated by SEM and TEM revealing columnar morphology and lack of porosity in both samples. The a-C:H:Zr coating was characterized by lower wettability by liquid copper than a-C:H:W coating and pure tungsten interlayer.