LasReX - Laser metal deposition using Hastelloy X blown powder for structural component repair

Laser welding of Hastelloy X has been found to cause heat affected zone liquation cracking. This is also a potential concern when using laser metal deposition with powder as feedstock material, with multi-layer material deposition as during LMDp generally providing a greater risk of crack formation. The thermal profile and its effect on microstructure and mechanical properties is therefore a practical concern for the industrial partners in this project. A suitable process window is therefore needed. The combination of the complex metallurgy of the material and the multi-parameter environment of LMDp necessitates the development of a suitable process window tailored to both material and application. Being able to understand and control the material changes and effects on mechanical performance enable the application of the technique in production and could provide a more controlled and repeatable repair process of cast and welded gas turbine components. The project is therefore of great interest to producers of structural gas turbine components for aerospace (GKN Aerospace) and land-based applications (Siemens).

The aim, therefore, is to research the influence of LMDp process parameters on the thermal profile and the microstructure evolution of Hastelloy X within the framework of a repair operation. As a result, design recommendations will be developed to enable the use of LMDp of Hastelloy X in component production.