{"id":{"repo_id":"wustl","oai_identifier":"oai:openscholarship.wustl.edu:etd-1072"},"canonical_url":"https://search.dev.ndltd.org/etd/wustl/oai:openscholarship.wustl.edu:etd-1072","repository":{"repo_id":"wustl","name":"Washington University in St. Louis","base_url":"https://openscholarship.wustl.edu/do/oai/"},"display":{"title":"The Effect of Equal Channel Angular Extrusion (ECAE) and Boron Additions on the Mechanical Properties of a Biomedical Ti-Nb-Zr-Ta (TNZT) Alloy","abstract":"New metastable-beta type titanium alloys based on the biocompatible elements Ti-Nb-Zr-Ta: TNZT) have been developed to address the shortcomings: e.g. incomplete biocompatibility, high modulus, etc.) of the traditionally used materials in joint replacement prostheses. Equal channel angular extrusion: ECAE) processing has the capability to improve the mechanical properties of these alloys to broaden their potential biomedical applications. The focus of this investigation is to evaluate and optimize the ECAE process to produce maximum property improvement, and explore the effectiveness of boron as a grain refining agent. Deformation mechanisms are identified for various processing conditions, and the strain distribution induced during extrusion is examined using finite element techniques. Multi-pass ECAE processed samples were examined using optical and transmission electron microscopy, and subjected to tensile, fatigue, and wear testing. It was found that ECAE has a beneficial impact on all of the properties tested. The modulus value was increased by approximately 25 percent, but it is still well below the value of other prosthesis materials.","abstract_html":"New metastable-beta type titanium alloys based on the biocompatible elements Ti-Nb-Zr-Ta: TNZT) have been developed to address the shortcomings: e.g. incomplete biocompatibility, high modulus, etc.) of the traditionally used materials in joint replacement prostheses. Equal channel angular extrusion: ECAE) processing has the capability to improve the mechanical properties of these alloys to broaden their potential biomedical applications. The focus of this investigation is to evaluate and optimize the ECAE process to produce maximum property improvement, and explore the effectiveness of boron as a grain refining agent. Deformation mechanisms are identified for various processing conditions, and the strain distribution induced during extrusion is examined using finite element techniques. Multi-pass ECAE processed samples were examined using optical and transmission electron microscopy, and subjected to tensile, fatigue, and wear testing. It was found that ECAE has a beneficial impact on all of the properties tested. The modulus value was increased by approximately 25 percent, but it is still well below the value of other prosthesis materials.","abstract_has_math":false,"creators":["Colombo, Gian"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering and Materials Science","degree_department":null,"school":null,"contributors":["Shankar Sastry"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-01-01T08:00:00Z","date_published":"2010-01-01T08:00:00Z","updated_at":"2026-07-24T06:13:14Z","subjects":["Engineering","Metallurgy"],"languages":["English (en)"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7RR1W9T"],"render_values":[{"text":"https://doi.org/10.7936/K7RR1W9T","href":"https://doi.org/10.7936/K7RR1W9T","code":true}]}]},"links":{"outbound_url":"https://openscholarship.wustl.edu/etd/73","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Shankar Sastry"]},{"key":"dc:creator","label":"Author","values":["Colombo, Gian"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2010-01-01T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering and Materials Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering","Metallurgy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English (en)"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://openscholarship.wustl.edu/etd/73"]},{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7RR1W9T"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["New metastable-beta type titanium alloys based on the biocompatible elements Ti-Nb-Zr-Ta: TNZT) have been developed to address the shortcomings: e.g. incomplete biocompatibility, high modulus, etc.) of the traditionally used materials in joint replacement prostheses. Equal channel angular extrusion: ECAE) processing has the capability to improve the mechanical properties of these alloys to broaden their potential biomedical applications. The focus of this investigation is to evaluate and optimize the ECAE process to produce maximum property improvement, and explore the effectiveness of boron as a grain refining agent. Deformation mechanisms are identified for various processing conditions, and the strain distribution induced during extrusion is examined using finite element techniques. Multi-pass ECAE processed samples were examined using optical and transmission electron microscopy, and subjected to tensile, fatigue, and wear testing. It was found that ECAE has a beneficial impact on all of the properties tested. The modulus value was increased by approximately 25 percent, but it is still well below the value of other prosthesis materials."]},{"key":"dc:title","label":"Title","values":["The Effect of Equal Channel Angular Extrusion (ECAE) and Boron Additions on the Mechanical Properties of a Biomedical Ti-Nb-Zr-Ta (TNZT) Alloy"]}]}],"canonical_facts":{"dc:contributor":["Shankar Sastry"],"dc:creator":["Colombo, Gian"],"dc:date.available":["2010-01-01T08:00:00Z"],"dc:description.abstract":["New metastable-beta type titanium alloys based on the biocompatible elements Ti-Nb-Zr-Ta: TNZT) have been developed to address the shortcomings: e.g. incomplete biocompatibility, high modulus, etc.) of the traditionally used materials in joint replacement prostheses. Equal channel angular extrusion: ECAE) processing has the capability to improve the mechanical properties of these alloys to broaden their potential biomedical applications. The focus of this investigation is to evaluate and optimize the ECAE process to produce maximum property improvement, and explore the effectiveness of boron as a grain refining agent. Deformation mechanisms are identified for various processing conditions, and the strain distribution induced during extrusion is examined using finite element techniques. Multi-pass ECAE processed samples were examined using optical and transmission electron microscopy, and subjected to tensile, fatigue, and wear testing. It was found that ECAE has a beneficial impact on all of the properties tested. The modulus value was increased by approximately 25 percent, but it is still well below the value of other prosthesis materials."],"dc:identifier":["https://openscholarship.wustl.edu/etd/73"],"dc:identifier.doi":["https://doi.org/10.7936/K7RR1W9T"],"dc:language":["English (en)"],"dc:subject":["Engineering","Metallurgy"],"dc:title":["The Effect of Equal Channel Angular Extrusion (ECAE) and Boron Additions on the Mechanical Properties of a Biomedical Ti-Nb-Zr-Ta (TNZT) Alloy"],"thesis:degree_discipline":["Mechanical Engineering and Materials Science"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T06:13:14Z"}