Study and modeling of the transition from conduction to keyhole mode during SLM process.

Αλεξοπούλου, Βασιλική; Alexopoulou, Vasiliki

dc.contributor.author	Αλεξοπούλου, Βασιλική	el
dc.contributor.author	Alexopoulou, Vasiliki	en
dc.date.accessioned	2021-09-13T10:23:32Z
dc.date.available	2021-09-13T10:23:32Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/53839
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.21537
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/gr/	*
dc.subject	SLM	en
dc.subject	Conduction μορφή	el
dc.subject	Conducton mode	en
dc.subject	Keyhole mode	en
dc.subject	Innovative model	en
dc.subject	Keyhole μορφή	el
dc.subject	Καινοτόμο μοντέλο	el
dc.subject	Ti6Al4V	en
dc.title	Study and modeling of the transition from conduction to keyhole mode during SLM process.	en
heal.type	bachelorThesis
heal.secondaryTitle	Μελέτη και μοντελοποίηση της μετάβασης από conduction σε keyhole μορφή κατά τη διάρκεια της SLM κατεργασίας.	el
heal.classification	Μη συμβατικές κατεργασίες/ Μίκρο-Νάνοκατεργασίες	el
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2021-07-20
heal.abstract	Additive manufacturing (AM), also known as 3D printing, is a transformative approach to industrial production that enables the creation of lighter, stronger parts and systems. It is yet, another technological advancement made possible by the transition from analog to digital processes. In recent decades, communications, imaging, architecture and engineering have all undergone their own digital revolutions. Now, AM can bring digital flexibility and efficiency to manufacturing operations. Additive manufacturing uses data computer-aided-design (CAD) software or 3D object scanners to direct hardware to deposit material, layer upon layer, in precise geometric shapes. As its name implies, additive manufacturing adds material to create an object. By contrast, when an object is created by traditional means, it is often necessary to remove material through milling, machining or other means. While additive manufacturing seems new to many, it has actually been around for several decades. In the right applications, additive manufacturing delivers a perfect trifecta of improved performance, complex geometries and simplified fabrication. As a result, opportunities abound for those who actively embrace additive manufacturing. The 1st chapter of this study is an introduction to AM processes. Evolution, fundamental steps, the categories and technologies, the advantages and challenges of AM are all presented. Moreover, the AM defects and post-processing are discussed. Finally, the most interesting applications and a forecast for the evolution of AM are given. The 2nd chapter focuses on a specific AM technology, known as Selective Laser Melting (SLM). The basic mechanism and equipment used are described in this study. Furthermore, the physical phenomena and their effect on final part properties are discussed. In the end, the melting pool geometry, the input parameters (laser power, scanning speed, layer thickness, scan line spacing) and the different melting pool modes (conduction, keyhole, transition) are presented. In the 3rd chapter, the SLM state-of-the-art is given. Both experimental and theoretical papers, that try to estimate or predict the melting pool geometry, are presented. In the 4th chapter, a SLM simulation, that predicts the Ti6Al4V melting pool geometry, is developed. In this study, a heat transfer model coupled with deformed geometry physics, which utilize only one semi-empirical coefficient, is used. Temperature dependency of material thermophysical properties, material ablation, latent heat, convection, radiation and gaussian heat source physics are all taken into consideration. In the 5th chapter, the simulation results are compared with experimental data, taken by bibliography. Detailed discussion about how process parameters and the semi-empirical coefficient affect the melting pool geometry and modes is also given.	en
heal.advisorName	Μαρκόπουλος, Άγγελος	el
heal.committeeMemberName	Μαρκόπουλος, Άγγελος	el
heal.committeeMemberName	Μανωλάκος, Δημήτριος	el
heal.committeeMemberName	Βοσνιάκος, Γεώργιος-Χριστόφορος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Μηχανολόγων Μηχανικών. Τομέας Τεχνολογίας των Κατεργασιών	el
heal.academicPublisherID	ntua
heal.numberOfPages	149 σ.	el
heal.fullTextAvailability	false
heal.fullTextAvailability	false