Structure and Processing Relations in Ni-W Amorphous Particle Strengthened Ni Matrix Composites

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dc.contributor.authorZeagler, Andrewen
dc.contributor.committeechairAning, Alexander O.en
dc.contributor.committeememberSchultz, Jeffery P.en
dc.contributor.committeememberReynolds, William T. Jr.en
dc.contributor.departmentMaterials Science and Engineeringen
dc.date.accessioned2014-03-14T20:49:22Zen
dc.date.adate2009-01-06en
dc.date.available2014-03-14T20:49:22Zen
dc.date.issued2008-09-26en
dc.date.rdate2009-01-06en
dc.date.sdate2008-12-12en
dc.description.abstractReinforcing metals with compositionally similar amorphous particles has been found to create composites with good interfacial bonding. It is conceivable that significant additional strengthening in amorphous reinforced composites can be realized by creating high-aspect ratio reinforcements; attritor milling holds promise in this regard. In this work, mechanical alloying was used to produce equimolar Ni-W powder that became a composite of amorphous Ni-W with undissolved W crystallites. A mixture of nickel powder and ten volume percent amorphous Ni-W powder was blended by attritor milling for either one or three hours, compacted by combustion-driven compaction and sintered for up to fifty hours at 600ºC. Prolonged times at elevated temperatures led to crystallization of the amorphous reinforcement particles and dissolution of tungsten into the matrix. Vickers macrohardness tests on the sintered composites yielded lower-than-expected values. Microscopy after hardness testing revealed sliding of particles at their boundaries, indicating poor bonding between them. It is believed that the sintering process was compromised by contamination from organic vapor present in the tube furnace used. While attritor milling effected smaller reinforcement particles, the small increase in aspect ratio would likely have been insufficient to cause significant strengthening by shear load transfer.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-12122008-142405en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-12122008-142405/en
dc.identifier.urihttp://hdl.handle.net/10919/36084en
dc.publisherVirginia Techen
dc.relation.haspartZeagler-Thesis.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectmetal matrix compositesen
dc.subjectamorphousen
dc.subjectparticulate reinforcementen
dc.subjectmechanical alloyingen
dc.titleStructure and Processing Relations in Ni-W Amorphous Particle Strengthened Ni Matrix Compositesen
dc.typeThesisen
thesis.degree.disciplineMaterials Science and Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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