{"id":{"repo_id":"toronto-retro","oai_identifier":"oai:utoronto.scholaris.ca:1807/76180"},"canonical_url":"https://search.dev.ndltd.org/etd/toronto-retro/oai:utoronto.scholaris.ca:1807/76180","repository":{"repo_id":"toronto-retro","name":"University of Toronto","base_url":"https://utoronto.scholaris.ca/server/oai/request"},"display":{"title":"Design and Manufacture of an Ultrasonic Transducer for Long-term High Temperature Operation","abstract":"A novel design of ultrasonic transducers suitable for high temperatures is introduced. The transducers are targeted for trouble-free continuous operation at 700-800 째C for at least two years, with sufficiently wide bandwidth to yield good temporal resolution. The design and manufacturing procedures were formatted as a multistep sequence, adaptable to a variety of transducer specifications within a wide range of signal center frequencies (500 kHz to 10 MHz) and a wide range of signal bandwidths. Two transducer designs were pursued based on two different piezoelectric crystals as the active element: gallium phosphate and lithium niobate. A high Curie temperature of 1200 째C for lithium niobate and a high phase transition temperature of 970 째C for gallium phosphate, make the two piezoelements suitable for our application. A one-dimensional transducer model was used to model the transducer when used as a transmitter-receiver. The optimized acoustic impedance of the transducer backing element was determined to obtain desired signal center frequency of 3 MHz with 3 dB bandwidth of 90-95%. The concept of porous ceramics as a new generation of high temperature backing element is described. An acoustic model for wave propagation in such a medium was employed to estimate the optimal porosity and pore size for the backing element. Various high temperature adhesives and brazing alloys were investigated to bond stable bonding at high temperatures. An aluminum-based brazing alloy was found to yield reliable bonding between lithium niobate piezoelement and porous zirconia backing and alumina matching layer. None of the bonding agents resulted in acceptable bonding in the case of gallium phosphate piezoelement. The performance of the prototyped transducer at high temperature was tested on a steel plate. Despite some fluctuations in back-wall signal amplitude, clear signals were obtained.","abstract_html":"A novel design of ultrasonic transducers suitable for high temperatures is introduced. The transducers are targeted for trouble-free continuous operation at 700-800 째C for at least two years, with sufficiently wide bandwidth to yield good temporal resolution. The design and manufacturing procedures were formatted as a multistep sequence, adaptable to a variety of transducer specifications within a wide range of signal center frequencies (500 kHz to 10 MHz) and a wide range of signal bandwidths. Two transducer designs were pursued based on two different piezoelectric crystals as the active element: gallium phosphate and lithium niobate. A high Curie temperature of 1200 째C for lithium niobate and a high phase transition temperature of 970 째C for gallium phosphate, make the two piezoelements suitable for our application. A one-dimensional transducer model was used to model the transducer when used as a transmitter-receiver. The optimized acoustic impedance of the transducer backing element was determined to obtain desired signal center frequency of 3 MHz with 3 dB bandwidth of 90-95%. The concept of porous ceramics as a new generation of high temperature backing element is described. An acoustic model for wave propagation in such a medium was employed to estimate the optimal porosity and pore size for the backing element. Various high temperature adhesives and brazing alloys were investigated to bond stable bonding at high temperatures. An aluminum-based brazing alloy was found to yield reliable bonding between lithium niobate piezoelement and porous zirconia backing and alumina matching layer. None of the bonding agents resulted in acceptable bonding in the case of gallium phosphate piezoelement. The performance of the prototyped transducer at high temperature was tested on a steel plate. Despite some fluctuations in back-wall signal amplitude, clear signals were obtained.","abstract_has_math":false,"creators":["Amini, Mohammad Hossein"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Mechanical and Industrial Engineering","school":null,"contributors":[],"advisors":["Sinclair, Anthony N","Coyle, Thomas W"],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-11","date_published":"2016-11","updated_at":"2026-07-27T21:28:09Z","subjects":["High temperature Environments","Long-term operation","Non-Destructive Testing","Piezoelectric Transducers","ULtrasonics"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1807/76180","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Sinclair, Anthony N","Coyle, Thomas W"]},{"key":"dc:contributor.department","label":"Department","values":["Mechanical and Industrial Engineering"]},{"key":"dc:creator","label":"Author","values":["Amini, Mohammad Hossein"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-11"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-03-22T04:00:33Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-03-22T04:00:33Z"]},{"key":"dc:date.issued","label":"Date","values":["2016-11"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["High temperature Environments","Long-term operation","Non-Destructive Testing","Piezoelectric Transducers","ULtrasonics"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1807/76180"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A novel design of ultrasonic transducers suitable for high temperatures is introduced. The transducers are targeted for trouble-free continuous operation at 700-800 째C for at least two years, with sufficiently wide bandwidth to yield good temporal resolution. The design and manufacturing procedures were formatted as a multistep sequence, adaptable to a variety of transducer specifications within a wide range of signal center frequencies (500 kHz to 10 MHz) and a wide range of signal bandwidths. Two transducer designs were pursued based on two different piezoelectric crystals as the active element: gallium phosphate and lithium niobate. A high Curie temperature of 1200 째C for lithium niobate and a high phase transition temperature of 970 째C for gallium phosphate, make the two piezoelements suitable for our application. A one-dimensional transducer model was used to model the transducer when used as a transmitter-receiver. The optimized acoustic impedance of the transducer backing element was determined to obtain desired signal center frequency of 3 MHz with 3 dB bandwidth of 90-95%. The concept of porous ceramics as a new generation of high temperature backing element is described. An acoustic model for wave propagation in such a medium was employed to estimate the optimal porosity and pore size for the backing element. Various high temperature adhesives and brazing alloys were investigated to bond stable bonding at high temperatures. An aluminum-based brazing alloy was found to yield reliable bonding between lithium niobate piezoelement and porous zirconia backing and alumina matching layer. None of the bonding agents resulted in acceptable bonding in the case of gallium phosphate piezoelement. The performance of the prototyped transducer at high temperature was tested on a steel plate. Despite some fluctuations in back-wall signal amplitude, clear signals were obtained."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:title","label":"Title","values":["Design and Manufacture of an Ultrasonic Transducer for Long-term High Temperature Operation"]}]}],"canonical_facts":{"dc:contributor.advisor":["Sinclair, Anthony N","Coyle, Thomas W"],"dc:contributor.department":["Mechanical and Industrial Engineering"],"dc:creator":["Amini, Mohammad Hossein"],"dc:date":["2016-11"],"dc:date.accessioned":["2017-03-22T04:00:33Z"],"dc:date.available":["2017-03-22T04:00:33Z"],"dc:date.issued":["2016-11"],"dc:description.abstract":["A novel design of ultrasonic transducers suitable for high temperatures is introduced. The transducers are targeted for trouble-free continuous operation at 700-800 째C for at least two years, with sufficiently wide bandwidth to yield good temporal resolution. The design and manufacturing procedures were formatted as a multistep sequence, adaptable to a variety of transducer specifications within a wide range of signal center frequencies (500 kHz to 10 MHz) and a wide range of signal bandwidths. Two transducer designs were pursued based on two different piezoelectric crystals as the active element: gallium phosphate and lithium niobate. A high Curie temperature of 1200 째C for lithium niobate and a high phase transition temperature of 970 째C for gallium phosphate, make the two piezoelements suitable for our application. A one-dimensional transducer model was used to model the transducer when used as a transmitter-receiver. The optimized acoustic impedance of the transducer backing element was determined to obtain desired signal center frequency of 3 MHz with 3 dB bandwidth of 90-95%. The concept of porous ceramics as a new generation of high temperature backing element is described. An acoustic model for wave propagation in such a medium was employed to estimate the optimal porosity and pore size for the backing element. Various high temperature adhesives and brazing alloys were investigated to bond stable bonding at high temperatures. An aluminum-based brazing alloy was found to yield reliable bonding between lithium niobate piezoelement and porous zirconia backing and alumina matching layer. None of the bonding agents resulted in acceptable bonding in the case of gallium phosphate piezoelement. The performance of the prototyped transducer at high temperature was tested on a steel plate. Despite some fluctuations in back-wall signal amplitude, clear signals were obtained."],"dc:description.degree":["Ph.D."],"dc:identifier.uri":["http://hdl.handle.net/1807/76180"],"dc:subject":["High temperature Environments","Long-term operation","Non-Destructive Testing","Piezoelectric Transducers","ULtrasonics"],"dc:title":["Design and Manufacture of an Ultrasonic Transducer for Long-term High Temperature Operation"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T21:28:09Z"}