From Legacy Alloys to Next-Gen Materials: the Future of Additive Manufacturing in Gas Turbine Hot Sections

Abstract The adoption of additive manufacturing (AM) in the turbomachinery sector, particularly for hot section gas turbine parts, has seen rapid growth over the past decade. This technological shift offers the potential to produce complex geometries that were previously unachievable using traditional methods. However, significant challenges remain, particularly in the high-temperature performance of AM-produced nickel- and cobalt-based superalloys. Superalloys such as IN738LC, IN939, Mar-M-247, and Mar-M-509 have been tested extensively, but they present issues related to creep resistance, oxidation, corrosion, and ductility when exposed to extreme turbine operating conditions. For example, IN738LC and Mar-M-247 have shown promise in their moderate temperature mechanical properties, but the manufacturing process, including selective laser melting (SLM), often leads to microstructural challenges like crack formation due to thermal gradients. To mitigate this, various strategies during manufacturing have been explored, which help enhance material structure and reduce cracking risks. However, these solutions remain imperfect, necessitating continued investigation into the materials’ long-term performance at elevated temperatures. Recent advancements in AM have led to the development of new superalloys specifically designed for gas turbine applications, including ABD1000, GRX810, LW4280, and the GammaPrint series alloys (GammaPrint 1100 and 700). These materials are engineered to match the limits of temperature resistance and oxidation performance of traditional alloys, but with the promise of improved printability using the SLM process. Initial tests of these newer alloys show promise of good creep resistance and high-temperature properties, positioning them as key contenders in future turbine engine applications. This paper examines both the current challenges and advancements in AM superalloys, presenting data on their performance and manufacturability. Through published studies and ongoing research, it becomes clear that while additive manufacturing offers revolutionary capabilities, optimizing the high-temperature performance of superalloys remains crucial for achieving widespread industrial adoption.