Microstructural Characterisation of TiC-TiN Gradient Coatings Deposited by Non-Reactive Magnetron Sputtering

Abstract

A concept for the deposition of TiC-TiN gradient coatings by non-reactive magnetron sputtering is presented Using symmetrically divided targets consisting of TiC and TiN parts thin graded films are deposited by moving the substrate below the target during deposition from the carbide rich to the nitride rich side. The composition of the growing film depends on the location of the substrates below the target. The gas pressure and substrate bias as deposition parameters show strong influence on the constitution and mechanical properties of the films (hardness, critical load of failure). In AES investigations the distribution of the composition of the graded films show the predicted values and correlate to the location dependent composition of stationary coated samples below the divided target For Ar-gas pressures between 0,2Pa x >0,1 and 0,1 < y < 0,9 was found. TEM investigations show columnar structure of gradient coatings with composition dependent grain size.