Author
Moataz M. Attallah
Other affiliations: Caterpillar Inc., University of Manchester, University of Cambridge ...read more
Bio: Moataz M. Attallah is an academic researcher from University of Birmingham. The author has contributed to research in topics: Selective laser melting & Microstructure. The author has an hindex of 33, co-authored 147 publications receiving 6218 citations. Previous affiliations of Moataz M. Attallah include Caterpillar Inc. & University of Manchester.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the influence of selective laser melting (SLM) process parameters (laser power, scan speed, scan spacing, and island size) on the porosity development in AlSi10Mg alloy builds has been investigated, using statistical design of experimental approach, correlated with the energy density model.
854 citations
TL;DR: In this paper, the development of surface structure and porosity of Ti-6Al-4V samples fabricated by selective laser melting under different laser scanning speeds and powder layer thicknesses has been studied and correlated with the melt flow behavior through both experimental and modelling approaches.
689 citations
20 Aug 2013-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the tensile properties measured before and after HIPing were analyzed using optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD).
Abstract: Ti–6Al–4V samples have been prepared by selective laser melting (SLM) with varied processing conditions. Some of the samples were stress-relieved or hot isostatically pressed (HIPed). The microstructures of all samples were characterised using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) and the tensile properties measured before and after HIPing. It was found that the porosity level generally decreased with increase of laser power and laser scanning speed. Horizontally built samples were found to have a higher level of porosity than vertically built samples. The as-fabricated microstructure was dominated by columnar grains and martensites. HIPing closed the majority of the pores and also fully transformed the martensite into α and β phases. The as-fabricated microstructure exhibits very high tensile strengths but poor ductility with elongation generally smaller than 10%. The horizontally built samples show even lower elongation than vertically built samples. HIPing considerably improved ductility but led to a reduction in strength. With HIPing, the SLMed samples were found to show tensile properties comparable with those thermomechanically processed and annealed samples.
566 citations
TL;DR: In this paper, the authors used optical and SEM micrographs to show the observed grain structure in the SLM fabricated and Hot Isostatically Pressed (HIPped) material and found that the repeating pattern shown in the grain structure has been linked to the overlapping of the "island" pattern used as standard in the Concept Laser M2 powder-bed facility.
556 citations
TL;DR: In this article, microstructural characterisation was performed for IN718 thin-walled builds, produced using direct laser fabrication (DLF), to understand the influence of the variations in the deposition path and the laser power on the microtexture, grain structures and intermetallic particle morphology development.
404 citations
Cited by
More filters
Journal Article•
TL;DR: This book by a teacher of statistics (as well as a consultant for "experimenters") is a comprehensive study of the philosophical background for the statistical design of experiment.
Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON
13,333 citations
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
31 Oct 2001
TL;DR: The American Society for Testing and Materials (ASTM) as mentioned in this paper is an independent organization devoted to the development of standards for testing and materials, and is a member of IEEE 802.11.
Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.
3,792 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
Proceedings Article•
[...]
TL;DR: The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images.
Abstract: MUCKE aims to mine a large volume of images, to structure them conceptually and to use this conceptual structuring in order to improve large-scale image retrieval. The last decade witnessed important progress concerning low-level image representations. However, there are a number problems which need to be solved in order to unleash the full potential of image mining in applications. The central problem with low-level representations is the mismatch between them and the human interpretation of image content. This problem can be instantiated, for instance, by the incapability of existing descriptors to capture spatial relationships between the concepts represented or by their incapability to convey an explanation of why two images are similar in a content-based image retrieval framework. We start by assessing existing local descriptors for image classification and by proposing to use co-occurrence matrices to better capture spatial relationships in images. The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images. Consequently, we introduce methods which tackle these two problems and compare results to state of the art methods. Note: some aspects of this deliverable are withheld at this time as they are pending review. Please contact the authors for a preview.
2,134 citations