Persistent Link:
http://hdl.handle.net/10150/291491
Title:
Process control of GASAR porous metals
Author:
Apprill, Jon M., 1974-
Issue Date:
1998
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
GASAR porous metals are produced by melting under a partial pressure of hydrogen and then casting into a mold that ensures directional solidification. Hydrogen is driven out of solution and grows as cylindrical pores normal to the solidification front. Experiments have been performed to produce GASARs from pure Ni and Inconel 718, a nickel-base superalloy. The processing variables studied in these experiments included the pressure of H₂(g), total pressure, superheat, and solidification rate. An analysis that considers heterogeneous bubble nucleation was developed that identifies processing conditions in which H₂(g) bubbles are stable in the liquid before solidification. It is hypothesized that these conditions lead to low porosity because the bubbles float out of the melt and are not incorporated into the final porosity. Experimental data are shown to support this hypothesis.
Type:
text; Thesis-Reproduction (electronic)
Keywords:
Engineering, Metallurgy.; Engineering, Materials Science.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Graduate College; Materials Science and Engineering
Degree Grantor:
University of Arizona
Advisor:
Poirier, David R.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleProcess control of GASAR porous metalsen_US
dc.creatorApprill, Jon M., 1974-en_US
dc.contributor.authorApprill, Jon M., 1974-en_US
dc.date.issued1998en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractGASAR porous metals are produced by melting under a partial pressure of hydrogen and then casting into a mold that ensures directional solidification. Hydrogen is driven out of solution and grows as cylindrical pores normal to the solidification front. Experiments have been performed to produce GASARs from pure Ni and Inconel 718, a nickel-base superalloy. The processing variables studied in these experiments included the pressure of H₂(g), total pressure, superheat, and solidification rate. An analysis that considers heterogeneous bubble nucleation was developed that identifies processing conditions in which H₂(g) bubbles are stable in the liquid before solidification. It is hypothesized that these conditions lead to low porosity because the bubbles float out of the melt and are not incorporated into the final porosity. Experimental data are shown to support this hypothesis.en_US
dc.typetexten_US
dc.typeThesis-Reproduction (electronic)en_US
dc.subjectEngineering, Metallurgy.en_US
dc.subjectEngineering, Materials Science.en_US
thesis.degree.nameM.S.en_US
thesis.degree.levelmastersen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineMaterials Science and Engineeringen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorPoirier, David R.en_US
dc.identifier.proquest1392407en_US
dc.identifier.bibrecord.b39123212en_US
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