For several decades, the increasing productivity in many industrial domains has led to a significant and ever-increased interest to protective and hard coatings. In this context, titanium-aluminum nitrides were developed and are now widely used in a large range of applications, due to their high hardness, good thermal stability, and oxidation resistance. This chapter reviews the thermodynamical characteristics of the Ti-Al-N system by reporting the progress made in the description of the Ti-Al-N phase diagram and the main mechanical and chemical properties of Ti1−xAlxN-based coatings. As a metastable phase, the existence of the fcc-Ti1−xAlxN depends on particular process parameters, allowing stabilizing this desirable solid solution. The influence of process parameters, with a particular interest for chemical vapor deposition (CVD) methods, on morphology and crystallographic structure is then described. The structure of Ti1−xAlxN thin films depends also on the aluminum content as well as on the annealing temperature, due to the spinodal nature of the Ti-Al-N system. These changes of crystallographic structure can induce an improvement of the hardness, oxidation resistance, and wear behavior of these coatings. The main mechanical and chemical properties of physical vapor deposition (PVD) and CVD Ti1−xAlxN-based coatings are also described.
Part of the book: Coatings and Thin-Film Technologies
Surface coating is of a great interest to increase the performances of the materials and extend its lifetime. High entropy films (HEFs) become the hot spot for developing surface engineering applications due to their good performances. They are reported to have superior properties such as good corrosion, wear resistance and excellent high temperature oxidation. Various deposition techniques have been exploited to fabricate HEFs such as laser cladding, spraying, sputter deposition and electrochemical deposition. These techniques are known to be an easy process to achieve a rapid quenching. Magnetron sputtering is seen as the most efficient methods to deposit the HEFs. Different gas can be used to prepare the ceramic materials. Besides, the deposition parameters reveal a strong influence on the physicochemical properties of HEFs. Working pressure, substrate temperature, bias voltage and gas mixture flow ratios have been reported to influence the morphology, microstructure, and functional properties of HEFs. The chapter overviews the development of the recent HEFs prepared by magnetron sputtering technique. First, it describes the principal of the technique. Then, it reports the classes of HEFs followed by the effect of the deposition parameters on their different properties. Applications have been developed using some HEFs for biomaterials and machining process.
Part of the book: High Entropy Materials