Author
Tom Craeghs
Other affiliations: Katholieke Universiteit Leuven
Bio: Tom Craeghs is an academic researcher from Materialise NV. The author has contributed to research in topics: Selective laser melting & Selective laser sintering. The author has an hindex of 18, co-authored 47 publications receiving 3803 citations. Previous affiliations of Tom Craeghs include Katholieke Universiteit Leuven.
Papers
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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 article, the authors discuss the principle and relevance of an in situ monitoring system for selective laser melting (SLM) which enables the operator to monitor the quality of the SLM job on-line and estimate the part accordingly.
Abstract: This paper discusses the principle and the relevance of an in situ monitoring system for selective laser melting (SLM). This system enables the operator to monitor the quality of the SLM job on-line and estimate the quality of the part accordingly. The monitoring system consists of two major developments in hardware and software. The first development, essential for a suitable monitoring system, is the design of a complete optical sensor set-up. This set-up is equipped with two commercially available optical sensors connected to a field-programmable gate array (FPGA) which communicates directly with the machine control unit. While the sensors ensure a high-quality measurement of the melt pool, the FPGA’s main task is to transfer the images from the sensors into relevant values at high sample rates (above 10 kHz). The second development is the data analysis system to translate and visualize measured sensor values in the format of interpretable process quality images. The visualization is mainly done by a “mapping algorithm,” which transfers the measurements from a time-domain into a position-domain representation. Further off-line experiments illustrate an excellent compatibility between the in situ monitoring and the actual quality of the products. The resulting images coming out of this model illustrate melt pool variations which can be linked to pores that are present in the parts.
339 citations
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 describe which tools are and will be available to fulfil those requirements from the perspective of a laser machine manufacturer and set the focus on melt pool analysis and control.
242 citations
TL;DR: In this paper, a monitoring and control system is presented which enables monitoring the melt pool continously at high speed throughout the building process, in this way enabling feedback control of the process parameters.
241 citations
Cited by
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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: In this paper, the authors describe the complex relationship between additive manufacturing processes, microstructure and resulting properties for metals, and typical microstructures for additively manufactured steel, aluminium and titanium are presented.
2,837 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 article, a review of additive manufacturing (AM) techniques for producing metal parts are explored, with a focus on the science of metal AM: processing defects, heat transfer, solidification, solid-state precipitation, mechanical properties and post-processing metallurgy.
Abstract: Additive manufacturing (AM), widely known as 3D printing, is a method of manufacturing that forms parts from powder, wire or sheets in a process that proceeds layer by layer. Many techniques (using many different names) have been developed to accomplish this via melting or solid-state joining. In this review, these techniques for producing metal parts are explored, with a focus on the science of metal AM: processing defects, heat transfer, solidification, solid-state precipitation, mechanical properties and post-processing metallurgy. The various metal AM techniques are compared, with analysis of the strengths and limitations of each. Only a few alloys have been developed for commercial production, but recent efforts are presented as a path for the ongoing development of new materials for AM processes.
1,713 citations