Alloy development for High Temperature applications using the high entropy concept; part II

Important results from the project

** Denna text är maskinöversatt ** The purpose was to modify existing Ni-based superalloys (IN718Plus family) based on the High Entropilation (HEA) concept to improve their stability at elevated temperatures (up to ~ 750 ° C). The concept of high entropy combined with conventional amplification mechanisms was used to achieve this objective. Alloy production cost, sustainability aspects and density were also among other criteria for alloy design.

Expected long term effects

** Denna text är maskinöversatt ** The results have been satisfactory, although they have additional room for improvement (up to ~ 30% improvement in yield strength and final tensile strength compared to IN718 Plus from room temperature to 750 ° C). Heat treatment optimization was also helpful in achieving an improved strength-ductility balance. A preliminary welding test showed satisfactory results for some of the designed alloys. Deeper investigations of creep and fatigue properties are needed for further progress towards implementation in industrial applications.

Approach and implementation

** Denna text är maskinöversatt ** Computational thermodynamics were integrated with experimental work in this research. The alloy design strategy is promising and will therefore be further developed for full implementation also for other compositions and alloy categories. Specifically for one of the alloys, both mechanical and high temperature oxidation performance were promising compared to the reference alloy. Preliminary welding tests also showed satisfactory results for one of the alloys. Going further into the implementation phase would require a more in-depth study of the creep and fatigue properties.