| Abstract: |
Thermal sprayed coatings using arc spraying technology are still in consideration within different applications and especially used to cover large surface areas. Arc spray offers relatively low capital investment compared to other thermal spray processes in combination with operator friendly behaviour. In most cases arc sprayed coatings can be applied quickly with high application rates, even at thickness requirements above 1 mm. Arc spray coatings exhibit excellent properties related to corrosion, wear resistance, and machinability, which are necessary in many applications, e.g. pulp and paper or general industry. To maintain these coating characteristics, chromium is a common element use in the market. However, usage of chromium containing products, like cored wires, generate significant issues based on toxic hexavalent chromium fumes and regulations related to hexavalent chromium are becoming stricter.
Unfortunately, substitution of chromium within the chemical composition of the wire often requires the use of other higher priced elements like molybdenum, vanadium, or niobium to fulfil the coating properties. Nevertheless, there are opportunities to achieve excellent coating properties using lower priced and less hazardous element through optimized compositional design which need to be considered. Here the correlation between Oerlikon´s Rapid Alloy Design Tool (RAD) in combination with manufacturing possibilities have supported significant developments in chromium-free arc spray coating technology.
The aim of the presented work is to evaluate the properties of chromium-free coatings applied by arc spray to chromium containing standard materials and unique chemistries in the Oerlikon product portfolio.
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