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Ding, Z. (author), Brouwer, J.C. (author), Kwakernaak, C. (author), Zhu, Jia-Ning (author), Popovich, V. (author), Hermans, M.J.M. (author), Sloof, W.G. (author)To prevent premature triggering of the healing reaction in Mo-Si containing self-healing thermal barrier coating system, an oxygen impenetrable shell (α-Al<sub>2</sub>O<sub>3</sub>) around the sacrificial healing particles (MoSi<sub>2</sub>) is desired. Here an encapsulation method is presented through selective oxidation of Al in Mo(Al<sub>x...journal article 2023
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Ding, Z. (author), Brouwer, J.C. (author), Kwakernaak, C. (author), Hermans, M.J.M. (author), Popovich, V. (author), Quadakkers, Willem J. (author), Sloof, W.G. (author)Mo(Al<sub>x</sub>Si<sub>1-x</sub>)<sub>2</sub> alloy with x in the range of 0.35–0.65 were prepared by a one-step spark plasma sintering. To study the exclusive formation of an α-Al<sub>2</sub>O<sub>3</sub> scale, oxidation experiments were conducted in low and high oxygen partial pressure ambient at 1373 K; viz.: 10<sup>−14</sup> and 0.21...journal article 2023
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Breukelman, H. J. (author), Hermans, M.J.M. (author), Santofimia, Maria Jesus (author), Hidalgo Garcia, J. (author)Localised laser treatments enable the creation of sophisticated austenite/martensite mesostructures in Fe–Ni–C steel with the potential of achieving enhanced mechanical performance. The control of phase topology is essential to modify the properties of these structures on demand and requires a profound understanding of the effect of the...journal article 2023
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Mishra, V. (author), Babu, A. (author), Schreurs, R. (author), Wu, K. (author), Hermans, M.J.M. (author), Ayas, C. (author)Wire and Arc Additive Manufacturing (WAAM) emerged as a manufacturing process for large scale structures with extensive form and design freedom. WAAM can be fully exploited once the relation between the transient thermal history and its relation to microstructure development and resultant mechanical properties is established. This relation...journal article 2023
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Yan, Z. (author), Zhu, Jia-Ning (author), Borisov, Evgenii (author), Riemslag, A.C. (author), Scott, S.P. (author), Hermans, M.J.M. (author), Jovanova, J. (author), Popovich, V. (author)In energy absorption applications, architectured metallic materials generally suffer from unrecoverable deformation as a result of local yield damage or inelastic buckling. Nitinol (NiTi) offers recoverable deformation and energy dissipation due to its unique superelasticity, which can change the way we design and additively manufacture...journal article 2023
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Zhu, Jia-Ning (author), Liu, K. (author), Riemslag, A.C. (author), Tichelaar, F.D. (author), Borisov, Evgenii (author), Yao, Xiyu (author), Popovich, Anatoly (author), Huizenga, R.M. (author), Hermans, M.J.M. (author), Popovich, V. (author)Superelastic metallic materials possessing large recoverable strains are widely used in automotive, aerospace and energy conversion industries. Superelastic materials working at high temperatures and with a wide temperature range are increasingly required for demanding applications. Until recently, high-temperature superelasticity has only...journal article 2023
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Liang, X. (author), Bos, Cornelis (author), Hermans, M.J.M. (author), Richardson, I.M. (author)A cellular automata (CA) model has been developed for solidification simulation considering the kinetic undercooling at the interface. The state-of-the-art model incorporates a decentered growth algorithm to suppress the grid anisotropy and a generalized height function method to calculate the curvature accurately. To develop a CA model which...journal article 2023
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Ding, Z. (author), Brouwer, J.C. (author), Zhu, Jia-Ning (author), Popovich, V. (author), Hermans, M.J.M. (author), Sloof, W.G. (author)Boron containing MoSi<sub>2</sub> is a promising material for applications at high temperature, but the oxidation mechanism is still unclear. In this work, the high temperature (1100 °C) oxidation of B doped MoSi<sub>2</sub> in synthetic air has been investigated. A (boro)silicate layer is formed on the surface of the alloy, which features a...journal article 2023
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Sood, A. (author), Schimmel, Jim (author), Mattos Ferreira, V. (author), Bosman, Marko (author), Goulas, Constantinos (author), Popovich, V. (author), Hermans, M.J.M. (author)Invar alloys exhibit low thermal expansion and are useful in applications requiring dimensional stability when subject to temperature changes. Conventional production of Invar faces certain challenges that can be offset by exploiting additive manufacturing processes. This study employed pulsed gas tungsten arc welding (GTAW) to deposit Invar...journal article 2023
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Babu, A. (author), Ebrahimi, Amin (author), Wu, K. (author), Richardson, I.M. (author), Hermans, M.J.M. (author)Additive manufacturing offers a significant potential for producing metallic parts with distinctly localised microstructures and mechanical properties, commonly known as functional grading. While functional grading is generally accomplished through compositional variations or in-situ thermo-mechanical treatments, variation of process...journal article 2023
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Zhu, Jia-Ning (author), Zhu, Weijia (author), Borisov, Evgenii (author), Yao, Xiyu (author), Riemslag, A.C. (author), Goulas, Constantinos (author), Popovich, Anatoly (author), Yan, Z. (author), Tichelaar, F.D. (author), Mainali, D.P. (author), Hermans, M.J.M. (author), Popovich, V. (author)Additive manufacturing of NiTi shape memory alloys has attracted attention in recent years, due to design flexibility and feasibility to achieve four-dimensional (4D) function response. To obtain customized 4D functional responses in NiTi structures, tailorable phase transformation temperatures and stress windows as well as one-way or two-way...journal article 2023
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Zhu, Jia-Ning (author), Ding, Z. (author), Borisov, Evgenii (author), Yao, Xiyu (author), Brouwer, J.C. (author), Popovich, Anatoly (author), Hermans, M.J.M. (author), Popovich, V. (author)The pursuit of enhancing NiTi superelasticity through laser powder bed fusion (L-PBF) and [001] texture creation poses a challenge due to increased susceptibility to hot cracking in the resulting microstructure with columnar grains. This limitation restricts NiTi's application and contributes to material waste. To overcome this, we introduce...journal article 2023
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Ebrahimi, Amin (author), Hermans, M.J.M. (author)Laser butt welding of thin metal sheets is a widely used fusion-based joining technique in industrial manufacturing. A comprehensive understanding of the complex transport phenomena during the welding process is essential for achieving high-quality welds. In the present work, high-fidelity numerical simulations are employed to investigate the...journal article 2023
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Ebrahimi, Amin (author), Sattari, Mohammad (author), Bremer, Scholte J.L. (author), Luckabauer, Martin (author), Römer, Gert-willem R.B.E. (author), Richardson, I.M. (author), Kleijn, C.R. (author), Hermans, M.J.M. (author)The absorptivity of a material is a major uncertainty in numerical simulations of laser welding and additive manufacturing, and its value is often calibrated through trial-and-error exercises. This adversely affects the capability of numerical simulations when predicting the process behaviour and can eventually hinder the exploitation of fully...journal article 2022
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Zhu, Jia-Ning (author), Borisov, Evgenii (author), Liang, X. (author), Huizenga, R.M. (author), Popovich, Anatoly (author), Bliznuk, Vitaliy (author), Petrov, R.H. (author), Hermans, M.J.M. (author), Popovich, V. (author)Laser powder bed fusion (L-PBF), categorized as additive manufacturing technique, has a capability to fabricate NiTi (Nitinol) shape memory alloys with tailorable functional properties and complex geometries. An important processing parameter, hatch distance (h), is often related to macroscale structural defects; however, its role on...journal article 2022
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Ebrahimi, Amin (author), Babu, A. (author), Kleijn, C.R. (author), Hermans, M.J.M. (author), Richardson, I.M. (author)One of the challenges for development, qualification and optimisation of arc welding processes lies in characterising the complex melt-pool behaviour which exhibits highly non-linear responses to variations of process parameters. The present work presents a computational model to describe the melt-pool behaviour in root-pass gas metal arc...journal article 2021
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Ebrahimi, Amin (author), Kleijn, C.R. (author), Hermans, M.J.M. (author), Richardson, I.M. (author)Internal flow behaviour and melt-pool surface oscillations during arc welding are complex and not yet fully understood. In the present work, high-fidelity numerical simulations are employed to describe the effects of welding position, sulphur concentration (60-300 ppm) and travel speed (1.25-5 mms-1) on molten metal flow dynamics in fully...journal article 2021
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Fu, J. (author), Davis, T. P. (author), Kumar, A. (author), Richardson, I.M. (author), Hermans, M.J.M. (author)Oxide dispersion strengthened (ODS) steels are leading candidates for structural materials in nuclear fission and fusion power plants. Understanding the nature of nano-oxide particles in ODS steels is vital for a better control of the microstructure and mechanical properties to further their applications. In this study, electron microscopy...journal article 2021
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Fu, J. (author), Richardson, I.M. (author), Hermans, M.J.M. (author)Oxide dispersion-strengthened (ODS) Eurofer steel was laser welded using a short pulse duration and a designed pattern to minimise local heat accumulation. With a laser power of 2500 W and a duration of more than 3 ms, a full penetration can be obtained in a 1 mm thick plate. Material loss was observed in the fusion zone due to metal...journal article 2021
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Zhu, Jia-Ning (author), Borisov, Evgenii (author), Liang, X. (author), Farber, Eduard (author), Hermans, M.J.M. (author), Popovich, V. (author)Nitinol (NiTi) shape memory alloys fabricated by Laser Powder Bed Fusion (L-PBF) Additive Manufacturing (AM) have attracted much attention in recent years, as compared with conventional manufacturing processes it allows to produce Nitinol parts with high design complexity. Avoidance of defects during L-PBF is crucial for the production of...journal article 2021