High-entropy alloys (HEAs) have gained significant interest in recent years because of their outstanding properties. The AlCoCrFeNi alloy is one of the most studied HEAs. The effect of the manufacturing methods and heat treatment on the properties of the high-entropy AlCoCrFeNi alloy is under intense scrutiny. The effect of varying component content on properties of the alloy is frequently analysed. Aluminium is most popular due to its impact on alloy microstructure and occurrence of phases. Research is also conducted on the influence of alloying additives, such as boron and titanium, on the properties of the AlCoCrFeNi alloy. High-entropy alloys also have excellent mechanical properties at high temperatures. Excellent structural and functional properties make them suitable for application in the most demanding conditions. The research conducted on HEAs still provides a lot of new and valuable information on the properties and structures of these alloys. This article summarizes the most important information about HEAs, specifically the AlCoCrFeNi alloy.

The demand for metallic materials of exceptional tribological performance is rapidly growing due to constant development of automotive, tool or implant industry. As great attention nowadays is being paid to the surfacemodified materials, there is a need of establishing reliable methods for evaluation of coated metallic alloys. In this paper, methods for thickness, adhesion and mechanical properties measurement of anti-wear coatings are considered. The importance of altering the mechanical properties of the coating with regards to its expected wear performance is also discussed. According to the numerous findings, it is reasonable to pay attention to the hardness and Young’s modulus of the developed coating, as well as on the mismatch between its Young’s modulus and the elastic modulus of the substrate material. Information provided in this paper has been thoroughly illustrated and enriched with our own experience in the field.