Ion beam sputter deposition of thin insulating layers for applications in highly loaded contacts

In highly loaded lubricated rolling and sliding contacts which occur in different kinds of machines and machine elements the experimental determination of the temperature or pressure distribution is desirable. Measurements can be accomplished with thin film transducers which must be electrically insulated from the test specimens by a thin insulating layer. This layer has to withstand wear under extremely severe conditions. Ion beam sputter deposition was used to deposit insulating layers of Al 2O 3 between 0.6 and 4 μm thick onto steel discs. The durability of the coated discs was tested in a twin-disc machine under various working conditions. The insulating layers showed good durability under conditions of high hertzian pressure, high shear stress or high temperature stress caused by high slip values. Owing to their excellent mechanical properties the insulating layers are qualified for use as base layers for thin film transducers.