Processing of Ti Alloys by Additive Manufacturing: A Comparison of the Microstructures Obtained by Laser Cladding, Selective Laser Melting and Electron Beam Melting

Abstract

In this study, samples of alloy Ti-6Al-4V have been processed by different additive manufacturing techniques in order to compare the resulting microstructure. In all three processes, ultrafast cooling gives rise to strongly out-of-equilibrium microstructures. However, the specific of the heat flow in each process lead to significant differences as far as the grains orientation and the resulting microstructural anisotropy are concerned.

On the Laser Cladding of Ti Alloy Ti‐6Al‐4V With Low Laser Power

“…Figure 5 clearly shows that these grains extend over several deposition layers. Indeed, the primary grains formed by the solidification of a given layer tend to grow epitaxially on the primary grains from the previous layer, thus taking on an elongated morphology roughly parallel to the building direction [3,[6][7][8]. As a consequence, primary grains often cross several deposition layers.…”

“…Near-net-shape layer-by-layer additive processes are of great interest for the manufacturing of expensive materials such as Ti alloys, as they present a high potential for time and cost reduction [1][2][3]. Among the wide diversity of additive processes, laser cladding not only allows for a significant reduction in the consumption of raw material, it is also particularly suitable for restoring metallic components that may have suffered damage due to wear and/or impact by foreign objects [4,5].…”

In‐Situ High Temperature EBSD Analysis of the Effect of a Deformation Step on the Alpha to Beta Transition in Additive Manufactured Ti‐6Al‐4V

“…The high cost of this material, combined with the inherent difficulty of machining, makes the fabrication of Ti-6Al-4V aerospace components a natural match with the emerging technologies of Additive Manufacture (AM), that are capable of producing near-net-shape parts [2][3][4][5][6][7][8][9]. However, it is widely acknowledged that AM processes produce very different microstructures and textures to those that are traditionally developed through thermo-mechanical processing (TMP) [10], and this can lead to a different property balance in AM components that needs to be better understood.…”

“…In AM with Ti alloys large primary columnar grain structures, with a strong <001> fibre texture, are generally observed to form on solidification that extend over several layers of deposition [2,3,5]. On cooling to room temperature, the primary bcc grains transform to a fine hcp lamellar microstructure, the morphology of which is dependent on the cooling rate, with residual retained in thin layers between the laths [10].…”

Integration of Deformation Processing with Additive Manufacture of Ti‐6A1‐4V Components for Improved β Grain Structure and Texture

“…There is potential for the aerospace industry to greatly benefit from Additive Manufacture (AM) as it allows the near-net-shape manufacture of components [1][2][3][4][5][6][7] and provides more design freedom than traditional manufacturing, which can facilitate substantial weight savings through better design optimisation [1]. Ti-6Al-4V is one of the most widely used titanium aerospace alloys due to its high specific properties [8].…”