The efficiency of gas turbines plays an important role for a sustainable energy transition. Even for a possible hydrogen turbine application, an increased efficiency is associated with a lower environmental impact. Additionally, due to the increasing demand for cheap and sustainable commercial flights, gas turbine efficiency influences the design of airplanes. Gas turbines have been improved over decades. One main factor to increase gas turbine efficiency is to boost the turbine entry temperature. Consequently, this increases the requirements for materials for turbine blades in the combustion or turbine section of a gas turbine. Due to their combination of high strength and corrosion resistance at high temperatures, nickel-based superalloys are often used for this application. If nickel-based superalloys are combined with additive manufacturing (AM) the major subtractive processing steps after conventional casting of turbine blades  can be avoided and complex lightweight structures can be achieved. Unfortunately, the nickel-based superalloys withstanding the highest temperatures produce cracks during the AM process. This phenomenon is a result of the high cooling rates and repeated heating cycles, which build up strong residual stresses. The high alloying content and high amount of γ‘-fraction offer a variety of crack initiating spots and widen the solidification interval, resulting in defects. Since the γ‘-phase is the main contributor to the high temperature and creep properties of these alloys a perfect combination of mechanical properties and processability is often inaccessible.
We present a method to mitigate the cracking tendency of the non-processable nickel-based superalloy CM247LC in PBF-LB/M by adding reinforcing TiC-particles resulting in a metal matrix composite (MMC). The main focus of the investigation is the influence of the incorporated particles on the selection of PBF-LB/M process parameters and the evolution  of the microstructure.  The results show a reduction in crack-length and density in the new MMC by grain refinement and a change in local chemical composition and precipitation density. Additionally, conclusions on the resulting mechanical properties under application conditions  will be drawn.
The research will contribute to the development of more efficient turbine concepts and help energy and aerospace technology to develop into a more sustainable future.