Cathodic arc deposition of TiN and Zr-C,N- at low substrate temperatures using a pulsed bias voltage

From the various physical vapour deposition processes, ion plating is known to produce dense hard coating with an excellent adhesion to the substrates. By a combination of a d.c. and pulsed bias power supply with frequencies v=0-25kHz and a separate adjustment of the various peak voltages, a flexible deposition method is found to achieve adherent coatings at relatively low substrate temperatures. The new technique is applied for the coating of planar plates and drilling tools of high speed stell with TiN and Zr(C,N) using a cathodic arc plasma deposition process. The coatings are characterized performing scratch tests, Rockwell indentation tests and tool life tests. As a result the substrate temperature can be decreased to as low as (Delta)T=100-150 xC without loss of coating adhesion. Sometimes even better results are obtained at lower termperatures. A preliminiary understanding of the experimental observations is presented.