Manufacturing of an NiCr alloy by laser powder bed fusion for high temperature applications

Dennis Karlsson¹, Mikael Kjellén², Thomas Helander², Martin Sahlberg¹, Ulf Jansson¹

¹Department of Chemistry – Ångström Laboratory, Uppsala University, Sweden, ²Kanthal AB, Hallstahammar, Sweden

Ni-based alloys are commonly used in high temperature applications due to their excellent high temperature strength and oxidation resistance. There are many alloys in the Ni-based superalloy family, which cover many different chemical compositions and mechanical properties for various applications. The high Ni and Cr content contributes to the good corrosion and oxidation resistance at high temperatures. Therefore, the Ni80Cr20 alloy have seen a wide application within the dental field and as electrical elements, due to high corrosion resistance in combination with excellent high temperature strength. The introduction of laser powder bed fusion as a manufacturing route could greatly improve design possibilities of components for various applications. In this study, the Ni80Cr20 alloy was printed using an EOS M100 machine. A wide parameter window was investigated by varying laser power, scan speed and hatch distance to find suitable printing parameters. The alloy showed good printability and it was possible to produce high density components. The tensile properties were investigated and a high strength and elongation compared to reported properties of the conventionally produced material was obtained. Furthermore, the AM produced alloy showed a linear oxidation behaviour at high temperatures, indicating that the oxide layer formed is not fully protective. The oxidation rate at elevated temperatures is superior to e.g. Inconel 625.