Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys

Abstract

We present a brief review of the microstructures and mechanical properties of selected metallic alloys processed by additive manufacturing (AM). Three different alloys, covering a large range of technology readiness levels, are selected to illustrate particular microstructural features developed by AM and clarify the engineering paradigm relating process–microstructure–property. With Ti-6Al-4V the emphasis is placed on the formation of metallurgical defects and microstructures induced by AM and their role on mechanical properties. The effects of the large in-built dislocation density, surface roughness and build atmosphere on mechanical and damage properties are discussed using steels. The impact of rapid solidification inherent to AM on phase selection is highlighted for high-entropy alloys. Using property maps, published mechanical properties of additive manufactured alloys are graphically summarized and compared to conventionally processed counterparts.

Deformation and failure mechanisms of Ti–6Al–4V as built by selective laser melting

“…Additive manufacturing (AM) of titanium alloys is gaining an increasing attention because many titanium alloys are expensive and hard to form/machine with conventional methods [3,4]. There are several methods for 3D printing metals including selective laser melting (SLM), selective electron beam melting (SEBM), directed energy deposition (DED) and binder jetting [5,6]. In the present study, we focus on selective laser melting (SLM) of Ti-6Al-4V that has attracted a lot of interest and results in a lamellar microstructure [7][8][9][10][11][12][13][14][15].…”

Simulation of temperature, stress and microstructure fields during laser deposition of Ti–6Al–4V

“…There have been several studies regarding the LPBF modeling of Ti-6Al-4V (for recent reviews, refer to Refs. [1,8,9]). Karayagiz et al [10] reported the numerical and experimental analyses of temperature distribution during LPBF of Ti-6Al-4V.…”

Rafting‐Enabled Recovery Avoids Recrystallization in 3D‐Printing‐Repaired Single‐Crystal Superalloys

“…At some superalloy compositions and 3D‐printing parameters, detrimental Laves phase particles are reported 15. More importantly, a high density of dislocations build up in the heat‐affected zone (HAZ), due to unavoidable (often local) deformation under high thermal stresses during printing 16,17. Upon solution treatment at elevated temperatures, these regions riddled with dislocations readily undergo recrystallization (RX)18 that renders the microstructure polycrystalline, which would significantly degrade the high‐temperature creep performance of blades (Figure S1 in the Supporting Information) 2.…”