New scan strategy for Electron Beam Melting: Process window and microstructure evolution

Visa enkel post
dc.contributor.authorShojai, Ismail
dc.contributor.departmentChalmers tekniska högskola / Institutionen för industri- och materialvetenskapsv
dc.contributor.examinerKlement, Uta
dc.date.accessioned2019-08-28T08:02:01Z
dc.date.available2019-08-28T08:02:01Z
dc.date.issued2019sv
dc.date.submitted2019
dc.description.abstractFor the Electron Beam Melting Process, point melt scan strategy is evaluated instead of using a traditional hatch scan strategy. The effect on porosity, microstructure and basic mechanical properties are investigated using TiAl6V4 alloy powder. Different builds with different parameters (spot time, point distance and beam current) are the basis for this work with the objective generating a process window for dense and crack-free spec-imens. Porosity was characterized based on optical microscope imaging. The occur-rence of a new morphology of porosity which was not observed in traditional melting strategies, was investigated more in detail. Especially the relation between spot time and volume energy was analyzed more in detail. Specimens showing a relative density >99.8% were categorized as dense according to threshold set for this work and were therefore basis for further characterization. Thus, microstructural features were inves-tigated using OM on etched specimens and illustrated by correlating different point distances, volume energies, point energies and spot times. In addition, complementary Hardness tests were performed to gain a basic understanding of the mechanical proper-ties of the produced specimens. As a main result of this thesis, a process window for an EBM point melt strategy is proposed leading to dense specimens showing possibility to tailor the microstructure for desired applications respectivelysv
dc.identifier.coursecodeIMSX30sv
dc.identifier.urihttps://hdl.handle.net/20.500.12380/300190
dc.language.isoengsv
dc.setspec.uppsokTechnology
dc.subjectEBMsv
dc.subjectpoint meltsv
dc.subjectHatch scanning strategysv
dc.subjectpoint distancesv
dc.subjectspot timesv
dc.subjectscan strategysv
dc.subjectmicrostructuressv
dc.subjectporositysv
dc.subjectBIPsv
dc.subjectmelt poolsv
dc.subjectWidmanstätten structuresv
dc.subjectBasketweave structuresv
dc.titleNew scan strategy for Electron Beam Melting: Process window and microstructure evolutionsv
dc.type.degreeExamensarbete för masterexamensv
dc.type.uppsokH
Ladda ner
Original bundle
Visar 1 - 1 av 1
Bild (thumbnail)
Namn:
Ismail Shojai Masters Thesis 2019 Arcam-Chalmers.pdf
Storlek:
6.62 MB
Format:
Adobe Portable Document Format
Beskrivning:
Ladda ner
License bundle
Visar 1 - 1 av 1
Bild (thumbnail)
Namn:
license.txt
Storlek:
1.14 KB
Format:
Item-specific license agreed upon to submission
Beskrivning:
Ladda ner
Samling
Examensarbeten för masterexamen