Thin film performance from hybrid PVD-powder coating process

A new in-line reciprocating PVD prototype machine is described that enables a significant increase in throughput and product flexibility over conventional PVD machines. The research shows that conventional cathodic arc evaporation can be used in tandem with powder coating to produce planarized PVD films. However, poor adhesion was obtained for arc-evaporated zirconium films deposited on epoxy powder coatings in the prototype machine. Subsequent stress analysis showed that the epoxy undercoat substantially raised the residual stress in the zirconium and that the inadequate adhesion in the prototype machine was due to its rapid deposition rate. The analysis also predicted that inserting a material of an intermediate expansion coefficient between the film and epoxy undercoat should reduce the residual stress. Experimental trials confirmed that a copper interlayer raised the adhesion strength substantially and successful deposition could be achieved with the prototype machine. The zirconium films were dense and adherent with planarized, high gloss surfaces.