Additive Manufacturing of high temperature Materials and Assessment of Weldability (AMMAW)

Purpose and goal

** Denna text är maskinöversatt ** The aim of the project was to study the weldability of alloy 718 manufactured by the SLM method (L-PBF-718) and the influence of different types of heat treatment such as heat isostatic pressing (HIP)). The microstructure should be studied thoroughly using light optical and electron microscopes.

Expected results and effects

** Denna text är maskinöversatt ** L-PBF-718 in all conditions proved to be more crack prone compared to 718 sheet metal but L-PBF-718 in HIP: that condition is the most crack prone due to the larger grain size. In addition, L-PBF-718 in HIP: that state was less ductile. The microstructure of alloy 718 contains precipitates such as niobium carbide, titanium nitride and the low-melting lava phase in the interdendritic regions and along the grain boundaries. The cause of the heat cracks was related to the re-melting of these secondary phases present in the material.

Planned approach and implementation

** Denna text är maskinöversatt ** The project has been followed up regularly through meetings and monitoring of delivered deliverables. The scientific side has been evaluated first and foremost by publishing results at conferences and in scientific journals, which ultimately led to the date (2020-04-02) for the dissertation for the The project employed doctoral students (Tahira Raza) could be nailed. The research has led to a doctoral dissertation and six published articles in scientific journals as well as conference contributions at international conferences.