Etching and sputter-ion plating using pulsed d.c

Pulsed d.c. etching and biasing was used for the production of PVD hard coatings on decorative parts. For critical parts and precleaning the influence of the pulse frequency on the etching power is shown. The etching was done using a d.c. discharge in a pure argon atmosphere. The etching power at a specific frequency was limited by the number of interrupted arcings that occurred causing at each interruption a specific blanking out of power. Starting at a pulse frequency of 10 kHz more than 90% of the achievable maximum etching power was obtained even on critical parts which had not been perfectly precleaned. After etching, a sputter ion plating process for the deposition of ZrN x hard coatings was arranged by reactive magnetron sputtering. The coating processes were carried out using d.c. and pulsed d.c. bias. Starting from d.c. the influence of the pulse voltage on the structure and colour of the coatings is shown. As a result of the pulsed d.c. etching and biasing, coatings with dense microstructure and decorative brass-coloured ZrN x with high brilliance were produced at the reduced substrate temperature of 150°C.