Adhesion and residual stresses determination of thermally sprayed molybdenum on steel

Thermally sprayed molybdenum coatings are widely used to combat degradation of components and structures due to mechanical wear. However, the behavior and durability of these coatings are extremely dependent on their properties and on the spraying conditions. To date, efforts forwarded to develop thermal spray coatings technology have been focused on increasing the durability and integrity of the coating. Improvement of adherence of the deposit to the substrate, minimizing residual stress level and reducing porosity are the main objectives of these works. The aim of this paper is to measure the adherence of flame-sprayed molybdenum on steel substrate and to determine internal stress distribution at the interface of the obtained structure. The influence of a nickel–aluminum (80%, 20%) bond-coat and/or a post-annealing at 850 °C for 1 h in vacuum on the adherence and the residual stresses is also studied.