Microstructure characteristics and mechanical behaviour of a selective laser melted Inconel 718 alloy

Researching the Properties of Samples Fabricated Using Selective Laser Melting from A High-Temperature Nickel-Based Alloy

“…After type 2 thermal treatment, tensile strength was 1069.8 MPa, and extension deformation was at 8%, which is in agreement with the data recorded by other researchers [30][31][32]. Figure 6 and Table 2 show that at room temperature, the tensile strength, ultimate strength, and relative elongation of the tested material fabricated by SLM were higher than those of cast Inconel 718 alloy [33]. On the one hand, since the SLM process was characterized by a very high cooling rate, the printed part had a finer microstructure compared to the cast part.…”

“…Therefore, the investigated material fabricated by SLM was better when a fine Laves phase was precipitated in intercrystalline regions. However, as compared to forged Inconel 718, hardening particles of the second phase precipitate in lesser quantities in the researched selective material melted by laser, while the amount of a brittle Laves phase increased [33].…”

Analysis of Microstructure and Mechanical Properties in As-Built/As-Cast and Heat-Treated Conditions for IN718 Alloy Obtained by Selective Laser Melting and Investment Casting Processes

“…The existence of ″ is not well detected in the XRD pattern due the overlapping of their peaks with /′. There are no evident peaks for delta and Laves phases, perhaps due to their low volumetric fraction in the alloys obtained with both manufacturing processes, but strong <111> and <200> diffraction peaks for /′are observed in all the conditions studied, and it is consistent with XRD patterns reported for IN718 SLMed samples by some authors [25,30,32,36]. Li X. et al [32] also detected the presence of delta <211> diffraction peak in SLM samples manufactured with IN718 and direct aged, but no peak was detected in the asbuilt condition, which leads us to think that the temperatures used by them in the double stepped aging stage (higher than those used in this work) promoted the formation/modification of the delta phase in detriment of the precipitation of strengthening phases (′/″), which are not the desired precipitation kinetics for the SLM processing.…”

Process parameter optimization for selective laser melting of Inconel 718 superalloy and the effects of subsequent heat treatment on the microstructural evolution and mechanical properties

“…In addition, the heat flows in the longitudinal and transverse directions became more complicated. As a result, the grains along the boundary of molten tracks got more orientation, and even grew through the multi-layer molten tracks in the opposite direction of the heat flow, which was consistent with Huang et al's work [32]. Similarly, when the scanning speed was 300mm/s, more powders were molten and width of molten tracks became larger, which resulted in complex metallurgical reactions between layers.…”