Iridium coatings with titanium sub-layer deposited by RF magnetron sputtering

In this contribution, we report on the mechanical properties of iridium coatings with titanium sub-layer deposited by RF magnetron sputtering. Measurements of the coating adhesion were performed with scanning scratch test. The microhardness and effective Young's modulus were determined by nanoindentation test. In order to evaluate the suitability of the coating for glass molding applications, the contact behavior with a hot melt of a RoHS-compliant glass type was investigated. It was observed that iridium coatings with titanium sub-layer deposited on tungsten carbide substrates exhibited excellent thermomechanical durability. Furthermore, the coating was chemically resistant against the hot glass melt since no degradation of the coating's surface was observed after 5000 cyclic contacts with hot P-LaSF47 glass melt.