Progress and perspectives in laser additive manufacturing of key aeroengine materials

Aerospace is a key market driver for the advancement of additive manufacturing (AM) due to the huge demands in high-mix low-volume production of high-value parts, integrated complex part geometries and simplified fabrication workflow. Rapid and significant progress has been made in the laser additive manufacturing (LAM) of aeroengine materials, including the advanced high-strength steels, nickel-based superalloys and titanium-based alloys. Despite the extensive investigation of these three families of materials by the research community, there is a lack of comprehensive review on LAM of high strength steels, and existing gaps in published reviews on Ti-based alloys and Ni-based superalloys. Furthermore, although emerging materials such as high/medium entropy alloys and heterostructured materials exhibit promising mechanical performance, rigorous characterization, testing, qualification, and certification are still required before actual application in engine parts. Thus, it is still important and relevant to have a deep understanding on the relationship between process parameters – microstructures – mechanical properties in these widely used aeroengine materials, to drive the development of superior high-value alloys. This review aims to provide a critical and in-depth evaluation of laser powder bed fusion (LPBF) and laser directed energy deposition (LDED) technologies of the mentioned aeroengine materials. The review will summarize the material properties, performance envelops and outlines the research gaps of these aeroengine materials. Furthermore, perspectives on research opportunities, materials development, and new R&D approaches of LAM for the aeroengine materials are also highlighted. This work comprehensively reviews the recent development status of the laser additive manufacturing (LAM) process and key aeroengine materials in terms of process window, microstructure characteristics, mechanical properties, and their relationship (inner circle). On this basis, the perspectives on research opportunities, materials development and new R&D approaches for the aerospace components are also highlighted (outer circle). • Summarized correlations among process, microstructure and mechanical properties. • Outlined strength and weakness of laser additive manufacturing key aeroengine materials. • Elucidated Advancement of new laser additive manufacturing technologies. • Highlighted future directions of laser additive manufacturing aeroengine materials.