Author
Jeroen Heulens
Bio: Jeroen Heulens is an academic researcher from Katholieke Universiteit Leuven. The author has contributed to research in topics: Crystallization & Phase (matter). The author has an hindex of 6, co-authored 14 publications receiving 421 citations.
Papers
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TL;DR: In this article, the authors present a pragmatic engineering model to study aspects of the SLM process using an enthalpy formulation and accounting for shrinkage and laser light penetration, and investigate the importance of evaporation for a set of process parameters relevant to production.
271 citations
TL;DR: In this article, the authors present an overview of the scientific studies dedicated to the hot stage of slag processing, i.e. from the moment of slags/metal separation to complete cooling at the slag yard, and show that the functional properties of the cooled slag can be significantly enhanced by small or large scale additions to the high temperature slag and/or variations in the cooling path.
Abstract: Slags are an indispensable tool for the pyrometallurgical industry to extract and purify metals at competitive prices. Large volumes are produced annually, leading to important economical and ecological issues regarding their afterlife. To maximise the recycling potential, slag processing has become an integral part of the valorisation chain. However, processing is often directed solely towards the cooled slag. In this article, the authors present an overview of the scientific studies dedicated to the hot stage of slag processing, i.e. from the moment of slag/metal separation to complete cooling at the slag yard. Using in-depth case studies on C 2 S driven slag disintegration and chromium leaching, it is shown that the functional properties of the cooled slag can be significantly enhanced by small or large scale additions to the high temperature slag and/or variations in the cooling path, even without interfering with the metallurgical process. The technology to implement such hot stage processing steps in an industrial environment is currently available. No innovative technological solutions are required. Rather, advances in hot stage slag processing seem to rely primarily on further unravelling the relationships between process, structure and properties. This knowledge is required to identify the critical process parameters for quality control. Moreover, it could even allow to consciously alter slag compositions and cooling paths to tailor the slag to a certain application.
108 citations
TL;DR: In this article, a multicomponent multi-phase field model for isothermal crystallization of oxide melts is presented, where a paraboloid Gibbs energy is introduced to ensure correct phase equilibria and minimal solubility in the stoichiometric phase.
48 citations
TL;DR: In this paper, the crystal growth of Wollastonite (CaO·SiO2) in a 42CaO−10Al2O3−48SiO 2 melt is observed in situ at 1320 and 1370°C using a high-temperature confocal scanning laser microscope (CSLM).
Abstract: Crystal growth of Wollastonite (CaO·SiO2) in a 42CaO–10Al2O3–48SiO2 melt is observed in situ at 1320 ° C and 1370 ° C using a high-temperature confocal scanning laser microscope (CSLM). The crystallization is initiated by seeding the melt with Wollastonite particles, which is the primary phase at these temperatures and composition. At 1370 °C, a faceted growth form is observed, while at 1320 °C, dendritic, non-faceted growth occurs. The dendrite tip velocity is measured and compared with Ivantsov’s theory. The presented experimental technique proofs to be successful for characterizing isothermal crystallization of minerals in silicate melts.
23 citations
TL;DR: In this paper, an isothermal phase-field model for diffusion couples is employed to compare with the analytical solutions for the interface velocity in ternary two-phase diffusion couples.
14 citations
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TL;DR: A review of the emerging research on additive manufacturing of metallic materials is provided in this article, which provides a comprehensive overview of the physical processes and the underlying science of metallurgical structure and properties of the deposited parts.
4,192 citations
TL;DR: Additive manufacturing implies layer by layer shaping and consolidation of powder feedstock to arbitrary configurations, normally using a computer controlled laser as discussed by the authors, which is based on a novel materials incremental manufacturing philosophy.
Abstract: Unlike conventional materials removal methods, additive manufacturing (AM) is based on a novel materials incremental manufacturing philosophy. Additive manufacturing implies layer by layer shaping and consolidation of powder feedstock to arbitrary configurations, normally using a computer controlled laser. The current development focus of AM is to produce complex shaped functional metallic components, including metals, alloys and metal matrix composites (MMCs), to meet demanding requirements from aerospace, defence, automotive and biomedical industries. Laser sintering (LS), laser melting (LM) and laser metal deposition (LMD) are presently regarded as the three most versatile AM processes. Laser based AM processes generally have a complex non-equilibrium physical and chemical metallurgical nature, which is material and process dependent. The influence of material characteristics and processing conditions on metallurgical mechanisms and resultant microstructural and mechanical properties of AM proc...
2,402 citations
TL;DR: In this article, the development of the microstructure of the Ti-6Al-4V alloy processed by selective laser melting (SLM) was studied by light optical microscopy.
2,201 citations
TL;DR: In this paper, the high thermal gradients occurring during SLM lead to a very fine microstructure with submicron-sized cells, which can be modified to a weak cube texture along the building and scanning directions when a rotation of 90° of the scanning vectors within or between the layers is applied.
1,431 citations
TL;DR: In this paper, the effect of several heat treatments on the microstructure and mechanical properties of Ti6Al4V processed by Selective Laser Melting (SLM) is studied.
1,320 citations