In this study, Ni-20Cr alloy powder was synthesized and deposited on T22 boiler steel by HVOF spraying. Coated and uncoated test samples were placed in a silicon carbide tube furnace and subjected to cyclic oxidation conditions in 900 °C air. Oxidation kinetics were established via weight change measurements and oxidation products were characterized based on XRD and SEM-EDS analysis. The results show that in addition to improving the oxidation resistance of the steel, the Ni-20Cr coatings also reduced spallation due to the formation of a protective Cr2O3 phase.

Due to the demand for improved fuel economy as well as increased safety features, weight reduction is one of the major aims in the automotive industry. Future lightweight automotive components for the next car generation will probably use lots of magnesium alloy. These will form galvanic couples with other materials and may induce phenomena accelerating the corrosion rate of automotive components. The materials used were magnesium alloy AZ31B and several types of cold sprayed coating. The relative performance of each cold sprayed corrosion preventive compounds (CPC) was assessed in combination with the materials under several different electrochemical and accelerated corrosion tests. Baseline data for AZ31B with no CPC applied was also collected. CPC characteristics and properties are also included and discussed. The studies on bare Mg/Steel couples validated accelerated corrosion but found that CPC cold sprayed coatings mitigate corrosion rates. Thus Mg/Fe interfaces with defect-free cold sprayed coatings CPC can prevent buildup of corrosion products and reduce galvanic corrosion of automotive components.

Zn coatings have been applied on steel substrates used by Renault for the manufacturing of car bodies. We had the task to make these on-line thin coatings on smooth and non de-oiled surfaces with a translation speed of 1 m/s. Furthermore, in certain cases, these coatings were situated on a visible surface of the car body and on a precise position. The coating process must be adapted to the clean conditions of the current automotive industry. The development of this application has been focused mainly on the study of a new zinc powder grade as well as on the projection procedure which had to adapt to the constraints and to the productivity of an automotive manufacturing line. Cold Spray addresses all these requirements. Positive results obtained on the mechanical examinations, the accelerated corrosion tests and chippings tests demonstrate that such new coatings meet the specifications of the customer for this kind of processes.