Residual stress in protective ZrO 2 coatings produced by magnetron sputtering

Abstract

Residual stress in protective coatings, which can be caused by a mismatch of thermal expansion coefficients of substrate and coating or be intrinsic to the deposition technique, is a key phenomena for all applications. Avoiding any tensile stress, especially at high working temperatures, is a crucial condition for most protective ceramic coatings. We controlled the development of the residual stress in ZrO 2 coatings, partially stabilized by yttria during the sputter deposition on steel substrates. The information gained from in situ stress measurements allows thermal and intrinsic stress to be distinguished. Furthermore, the stress measurements allow coating stress and thermal properties of the coating to be tailored by varying the decomposition conditions. We show that a compressive ‘pre’-stress of about 1.7 × 10 9 Nm −2 at room temperature is sufficient to prevent high-temperature corrosion of Inconel 600 at 1000°C.