DEPOSITION OF BORON-CONTAINING COATINGS USING MO-PACVD PROCESS TO PROTECT ALUMINUM CASTING TOOLS

In this paper the synthesis of(B,C,N), Zr(B,C) and Zr(B,C,N) layers is investigated by means of DC pulsed plasma assisted CVD using organic compounds as precursors. The process parameters such as coating temper ature, gas pressure, gas mixture, plasma parameters are varied to depo sit functional coatings on hot-work steel used in the aluminium die ca sting industry. One of the objectives is to realize a layer type which withstands the severe service conditions in aluminium die casting. An other objective is to lower the coating temperature. The layers have b een studied by light- and scanning electron microscopy (SEM). The prop erties of the deposited layers are determined by various analytical me thods such as WDS-analysis for the chemical composition and X-ray diff raction (XRD) for the morphology. The hardness and adhesion of the lay ers were measured to determine the mechanical properties. The adhesion to liquid aluminium is investigated and compared to TiN layers deposi ted with TiCl4 as precursor.