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dc.contributor.author
Li, Xiaoshuang
dc.contributor.supervisor
Wegener, Konrad
dc.contributor.supervisor
Spolenak, Ralph
dc.contributor.supervisor
Leinenbach, Christian
dc.date.accessioned
2021-02-19T10:00:47Z
dc.date.available
2020-02-19T13:42:10Z
dc.date.available
2020-02-19T14:21:47Z
dc.date.available
2021-02-19T10:00:47Z
dc.date.issued
2019
dc.identifier.uri
http://hdl.handle.net/20.500.11850/400456
dc.identifier.doi
10.3929/ethz-b-000400456
dc.description.abstract
Advanced tools with superabrasive grains like diamond and cubic boron nitride are widely applied for machining high strength materials. The emerging Selective Laser Melting process has the potential to embed the superabrasives into such tools, so-called Metal Matrix Composites. Commercially available matrix alloys were developed for the conventional processes like casting, brazing which have cooling rates of several orders of magnitude lower than Selective Laser Melting. The present work focuses on developing new alloys for Metal Matrix Composites by Selective Laser Melting. Computationally assisted alloy screening is a cost-effective mean to narrow the alloy compositions of interest. To pre-screen alloys, rapid solidification experiments were carried out on the Cu-Sn-(Ti) and Ni-Cr-Si systems, which mimic the primary metallurgical process taking place in Selective Laser Melting. The results allow the understanding of the effects of cooling rates and compositions on the microstructural formation. In addition, in-situ synchrotron X-ray diffraction helps track phase transformations during the rapid solidification and the underlying mechanisms. Based on the results, a test alloy was selected for Selective Laser Melting. Sets of fundamental processing parameters were investigated to search for the processing window. Two superabrasives, i.e. diamond and cBN, were tested to study the effect of physical properties on the consolidation. It turned out that rapid solidification experiments enabled to estimate microstructure in as-built parts by observation of the same phases in the rapid solidification tests. The superabrasives are soundly bonded to the matrix by the formation of Ti carbides, borides and nitrides. Diamond content varies from 2 to 20 vol.%. Composites with 2 vol.% diamond can be free of cavities while density of defects significantly increases with diamond fractions. Using of Ti coated diamond showed limited improvement of density. However, 10 vol.% of cBN particles were successfully embedded into the final parts with far less defects. Besides, Finite Element Modelling was employed to support the understanding of the consolidation of the melt-diamond suspension. Due to the high thermal conductivity and volumetric heat capacity of diamond, abnormal heat transfer accounts for the occurrence of a large amount of defects and the poor mechanical performance.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
ETH Zurich
en_US
dc.rights.uri
http://rightsstatements.org/page/InC-NC/1.0/
dc.title
Rapid Solidification of Alloys and Selective Laser Melting of Metal Matrix Composites for Abrasive Applications
en_US
dc.type
Doctoral Thesis
dc.rights.license
In Copyright - Non-Commercial Use Permitted
dc.date.published
2020-02-19
ethz.size
152 p.
en_US
ethz.code.ddc
DDC - DDC::6 - Technology, medicine and applied sciences::670 - Manufacturing
en_US
ethz.identifier.diss
26266
en_US
ethz.publication.place
Zurich
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02130 - Dep. Maschinenbau und Verfahrenstechnik / Dep. of Mechanical and Process Eng.::02623 - Inst. f. Werkzeugmaschinen und Fertigung / Inst. Machine Tools and Manufacturing::03641 - Wegener, Konrad / Wegener, Konrad
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02130 - Dep. Maschinenbau und Verfahrenstechnik / Dep. of Mechanical and Process Eng.::02623 - Inst. f. Werkzeugmaschinen und Fertigung / Inst. Machine Tools and Manufacturing::03641 - Wegener, Konrad / Wegener, Konrad
en_US
ethz.date.deposited
2020-02-19T13:42:19Z
ethz.source
FORM
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.date.embargoend
2021-02-19
ethz.rosetta.installDate
2020-02-19T14:21:58Z
ethz.rosetta.lastUpdated
2022-03-29T05:18:32Z
ethz.rosetta.versionExported
true
ethz.COinS
ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Rapid%20Solidification%20of%20Alloys%20and%20Selective%20Laser%20Melting%20of%20Metal%20Matrix%20Composites%20for%20Abrasive%20Applications&rft.date=2019&rft.au=Li,%20Xiaoshuang&rft.genre=unknown&rft.btitle=Rapid%20Solidification%20of%20Alloys%20and%20Selective%20Laser%20Melting%20of%20Metal%20Matrix%20Composites%20for%20Abrasive%20Applications
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