Comparison of Residual Stresses in Inconel 718 Simple Parts Made by Electron Beam Melting and Direct Laser Metal Sintering

Sochalski-Kolbus, Lindsay M.; Payzant, E. Andrew; Cornwell, P; Watkins, Thomas R.; Babu, S. S.; DeHoff, R. T.; Lorenz, Matthias; Ovchinnikova, Olga S.; Duty, Chad

doi:10.1007/s11661-014-2722-2

Cited by 250 publications

(84 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Table 3 shows that δ-phase contains higher Nb, Mo and Ti concentrations than those in the matrix. Similar microstructure was found in a solution treated SLM fabricated IN718 followed by a double aging treatment by Wang et al [16] and was designated as δ-phase [38] with a rhombic crystal structure and Ni 3 Nb formula. However, Wang et al found the atomic ratio of Nb to Ni to be 1:1.77 (19.10 at % Nb and 33.86 at % Ni) [16], while in this study the ratio is equal to 1:4.17 with 8.75 at % Nb and 36.5 at % Ni.…”

Section: Phase Analysis Of Heat Treated Specimenssupporting

confidence: 72%

Structure, Texture and Phases in 3D Printed IN718 Alloy Subjected to Homogenization and HIP Treatments

Mostafa

Rubio

Braïlovski

et al. 2017

Metals

198

View full text Add to dashboard Cite

3D printing results in anisotropy in the microstructure and mechanical properties. The focus of this study is to investigate the structure, texture and phase evolution of the as-printed and heat treated IN718 superalloy. Cylindrical specimens, printed by powder-bed additive manufacturing technique, were subjected to two post-treatments: homogenization (1100 • C, 1 h, furnace cooling) and hot isostatic pressing (HIP) (1160 • C, 100 MPa, 4 h, furnace cooling). The Selective laser melting (SLM) printed microstructure exhibited a columnar architecture, parallel to the building direction, due to the heat flow towards negative z-direction. Whereas, a unique structural morphology was observed in the x-y plane due to different cooling rates resulting from laser beam overlapping. Post-processing treatments reorganized the columnar structure of a strong {002} texture into fine columnar and/or equiaxed grains of random orientations. Equiaxed structure of about 150 µm average grain size, was achieved after homogenization and HIP treatments. Both δ-phase and MC-type brittle carbides, having rough morphologies, were formed at the grain boundaries. Delta-phase formed due to γ -phase dissolution in the γ matrix, while MC-type carbides nucleates grew by diffusion of solute atoms. The presence of (Nb 0.78 Ti 0.22 )C carbide phase, with an fcc structure having a lattice parameter a = 4.43 Å, was revealed using Energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD) analysis. The solidification behavior of IN718 alloy was described to elucidate the evolution of different phases during selective laser melting and post-processing heat treatments of IN718.

show abstract

Section: Phase Analysis Of Heat Treated Specimenssupporting

confidence: 72%

Structure, Texture and Phases in 3D Printed IN718 Alloy Subjected to Homogenization and HIP Treatments

Mostafa

Rubio

Braïlovski

et al. 2017

Metals

198

View full text Add to dashboard Cite

show abstract

“…Residual stresses are always introduced in AM parts by large thermal gradients during processing, which can have seriously negative impact on mechanical properties [40]. In powder bed fusion (PBF) and direct energy deposition (DED) parts, the residual stresses are always compressive in the center and tensile at the edge [41][42][43][44]. Some researchers have been conducted to relieve the residual stresses, like preheating the substrate [40] and applying island scanning [45,46].…”

Section: Additive Manufacturingmentioning

confidence: 99%

Integration of physically-based and data-driven approaches for thermal field prediction in additive manufacturing

Jin

2018

Materials & Design

View full text Add to dashboard Cite

A quantitative understanding of thermal field evolution is vital for quality control in additive manufacturing (AM). Because of the unknown material parameters, high computational costs, and imperfect understanding of the underlying science, physically-based approaches alone are insufficient for component-scale thermal field prediction. Here, I present a new framework that integrates physically-based and data-driven approaches with quasi in situ thermal imaging to address this problem. The framework consists of (i) thermal modeling using 3D finite element analysis (FEA), (ii) surrogate modeling using functional Gaussian process, and (iii) Bayesian calibration using the thermal imaging data. Based on heat transfer laws, I first investigate the transient thermal behavior during AM using 3D FEA. A functional Gaussian process-based surrogate model is then constructed to reduce the computational costs from the high-fidelity, physically-based model. I finally employ a Bayesian calibration method, which incorporates the surrogate model and thermal measurements, to enable layer-to-layer thermal field prediction across the whole component. A case study on fused deposition modeling is conducted for components with 7 to 16 layers. The cross-validation results show that the proposed framework allows for accurate and fast thermal field prediction for components with different process settings and geometric designs. Integration of Physically-based and Data-driven Approaches for Thermal Field Prediction in Additive ManufacturingJingran Li GENERAL AUDIENCE ABSTRACT This paper aims to achieve the layer to layer temperature monitoring and consequently predict the temperature distribution for any new freeform geometry. An engineering statistical synergistic model is proposed to integrate the pure statistical methods and finite element modeling (FEM), which is physically meaningful as well as accurate for temperature prediction. Besides, this proposed synergistic model contains geometry information, which can be applied to any freeform geometry. This paper serves to enable a holistic cyber physical systems-based approach for the additive manufacturing (AM) not only restricted in fused deposition modeling (FDM) process but also can be extended to powder-based process like laser engineered net shaping (LENS) and selective laser sintering (SLS). This paper as well as the scheduled future works will make it affordable for customized AM including customized geometries and materials, which will greatly accelerate the transition from rapid prototyping to rapid manufacturing. This article demonstrates a first evaluation of engineering statistical synergistic model in AM technology, which gives a perspective on future researches about online quality monitoring and control of AM based data fusion principles. iv ACKNOWLEDGEMENTS

show abstract

“…Although this hypothesis has never previously been validated, SochalskiKolbus et al 67 recently experimentally evaluated it by using neutron scattering (see Figure 4 ).…”

Section: Demonstrationmentioning

confidence: 99%

Additive manufacturing of materials: Opportunities and challenges

et al. 2015

View full text Add to dashboard Cite

Figure 1. Development stages of big-area additive manufacturing (BAAM). (a) Gantrystyle robotic automation system, without any heating environment, was developed and integrated with a single-screw extrusion nozzle. (b) Initial material trials led to extensive distortion with acrylonitrile butadiene styrene (ABS) pellets, whereas use of pellets with ABS and carbon fi ber (CF) reduced the distortion. (c) Aerial view of the industrial-scale BAAM system developed by Local Motors. (d) The industrial-scale system was verifi ed by printing out a chassis of a small car, which was then integrated with an electric drive train. (e) The same technology was coupled with traditional manufacturing to produce a prototype similar to the Ford Shelby Cobra, which was also powered by an electric drive train. (f) The same technology has also been used to make molds for use in prototyping during traditional metal-forming processes. Reproduced with permission from Reference 10.

show abstract

Comparison of Residual Stresses in Inconel 718 Simple Parts Made by Electron Beam Melting and Direct Laser Metal Sintering

Cited by 250 publications

References 30 publications

Structure, Texture and Phases in 3D Printed IN718 Alloy Subjected to Homogenization and HIP Treatments

Structure, Texture and Phases in 3D Printed IN718 Alloy Subjected to Homogenization and HIP Treatments

Integration of physically-based and data-driven approaches for thermal field prediction in additive manufacturing

Additive manufacturing of materials: Opportunities and challenges

Contact Info

Product

Resources

About