Recent Advances in Alloy Development for Metal Additive Manufacturing in Gas Turbine/Aerospace Applications: A Review

A dozen or so alloys have been occupying the alloy landscape in metal additive manufacturing (MAM) in terms of addressing all aspects of research, aiding the maturity of development of these alloys towards various qualified applications for the aerospace/gas turbine sector, in the last decade or so. These include, AlSi10Mg, Al7Si0.5 Mg (F357), AlMgSc, Ti6Al4V, γ-TiAl, CoCrMo, Stellite12, IN718, IN625, CM247LC, HastelloyX, SS316L, CuCrNb, CuCrZr, to name a few. There has been a tremendous interest in the design and development of novel high temperature materials for MAMMAM: Metal Additive Manufacturing is a layer-by-layer manufacturing process making use of digital manufacturing, using lasers, electron beam, plasma, to melt powders and wires to enable direct manufacturing of metallic parts., with isotropic microstructure and high defect tolerance, to facilitate accelerated adoption of this technology to the aerospace sector. These include developing difficult to weld chemistries, alloys prone to cracking, alloys with improved high temperature properties, composite materials and creating novel alloys that are otherwise not achievable via conventional manufacturing. This article comprises a review of some of the innovations in alloy development that have been explored in recent times, comprising Aluminum, Titanium, Nickel, Cobalt, Copper, and others, with relevance to the gas turbine/aerospace arena. This includes over 100 different alloys that have been studied via laser powder bed fusion, direct energy deposition, binder jet technology, along with some novel methods of manufacturing new materials via MAM, to give a flavour for the importance that this subject has garnished in the scientific community in recent times.