A new approach of combined electroless nickel plating (ENP) and spark plasma sintering (SPS) was used to determine the feasibility of fracture toughness improvement of ZrO2. Nano-grained yttria stabilized zirconia (YSZ) particles of 100nm average diameter were coated with about 1-5 nm of nickel coating by ENP. To reduce nano particle agglomeration throughout the ENP process; vigorous agitation with an ultrasonic horn was used. The coated powder was characterized using Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Transmission electron microscopy (TEM) to study the microstructure and coating characteristics. The coating was identified to be predominantly nickel and of 1 to 5 nm thickness. The plated powder was dried and consolidated by Spark plasma sintering (SPS) with sintering times significantly lower than used in conventional sintering processes. The solid compact was evaluated for mechanical properties. Hardness values were obtained from Vickers micro hardness indentations; fracture toughness was calculated by indentation-crack-length measurement and three-point bend test of notched samples; flexural strength was measured by 3-point bend tests. The measured hardness is comparable to the results found in the literatures. The coated and uncoated zirconia show significantly higher average fracture toughness compare to existing values.
","abstract_html":"<p>A new approach of combined electroless nickel plating (ENP) and spark plasma sintering (SPS) was used to determine the feasibility of fracture toughness improvement of ZrO2. Nano-grained yttria stabilized zirconia (YSZ) particles of 100nm average diameter were coated with about 1-5 nm of nickel coating by ENP. To reduce nano particle agglomeration throughout the ENP process; vigorous agitation with an ultrasonic horn was used. The coated powder was characterized using Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Transmission electron microscopy (TEM) to study the microstructure and coating characteristics. The coating was identified to be predominantly nickel and of 1 to 5 nm thickness. The plated powder was dried and consolidated by Spark plasma sintering (SPS) with sintering times significantly lower than used in conventional sintering processes. The solid compact was evaluated for mechanical properties. Hardness values were obtained from Vickers micro hardness indentations; fracture toughness was calculated by indentation-crack-length measurement and three-point bend test of notched samples; flexural strength was measured by 3-point bend tests. The measured hardness is comparable to the results found in the literatures. The coated and uncoated zirconia show significantly higher average fracture toughness compare to existing values.</p>","abstract_has_math":false,"creators":["Jia, Kunlong"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Mechanical Engineering & Materials Science","degree_department":null,"school":null,"contributors":["Dr. Shankar Sastry","Dr. Shankar Sastry Dr. Srikanth Singamaneni Dr. Peng Bai"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-12-18T08:00:00Z","date_published":"2018-12-18T08:00:00Z","updated_at":"2026-07-24T06:13:05Z","subjects":["ceramic","zirconia","spark plasma sintering","electroless nickel coating","ductile phase toughening","Ceramic Materials","Engineering"],"languages":["English (en)"],"rights":["I have not registered my thesis with the U.S. Copyright Office, but intend to later."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://openscholarship.wustl.edu/eng_etds/431"],"render_values":[{"text":"https://openscholarship.wustl.edu/eng_etds/431","href":"https://openscholarship.wustl.edu/eng_etds/431","code":true}]}]},"links":{"outbound_url":"https://doi.org/7936/2amq-wx38","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dr. Shankar Sastry","Dr. Shankar Sastry Dr. Srikanth Singamaneni Dr. Peng Bai"]},{"key":"dc:creator","label":"Author","values":["Jia, Kunlong"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2019-01-01T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering & Materials Science","McKelvey School of Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["ceramic","zirconia","spark plasma sintering","electroless nickel coating","ductile phase toughening","Ceramic Materials","Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English (en)"]},{"key":"dc:rights","label":"Dc Rights","values":["I have not registered my thesis with the U.S. Copyright Office, but intend to later."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://doi.org/7936/2amq-wx38","https://openscholarship.wustl.edu/eng_etds/431"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Permanent URL: https://doi.org/7936/2amq-wx38"]},{"key":"dc:description.abstract","label":"Abstract","values":["A new approach of combined electroless nickel plating (ENP) and spark plasma sintering (SPS) was used to determine the feasibility of fracture toughness improvement of ZrO2. Nano-grained yttria stabilized zirconia (YSZ) particles of 100nm average diameter were coated with about 1-5 nm of nickel coating by ENP. To reduce nano particle agglomeration throughout the ENP process; vigorous agitation with an ultrasonic horn was used. The coated powder was characterized using Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Transmission electron microscopy (TEM) to study the microstructure and coating characteristics. The coating was identified to be predominantly nickel and of 1 to 5 nm thickness. The plated powder was dried and consolidated by Spark plasma sintering (SPS) with sintering times significantly lower than used in conventional sintering processes. The solid compact was evaluated for mechanical properties. Hardness values were obtained from Vickers micro hardness indentations; fracture toughness was calculated by indentation-crack-length measurement and three-point bend test of notched samples; flexural strength was measured by 3-point bend tests. The measured hardness is comparable to the results found in the literatures. The coated and uncoated zirconia show significantly higher average fracture toughness compare to existing values.
"]},{"key":"dc:title","label":"Title","values":["Electroless Nickel Plating and Spark Plasma Sintering of nano ZrO2 for Mechanical Property Enhancement"]}]}],"canonical_facts":{"dc:contributor":["Dr. Shankar Sastry","Dr. Shankar Sastry Dr. Srikanth Singamaneni Dr. Peng Bai"],"dc:creator":["Jia, Kunlong"],"dc:date.available":["2019-01-01T08:00:00Z"],"dc:description":["Permanent URL: https://doi.org/7936/2amq-wx38"],"dc:description.abstract":["A new approach of combined electroless nickel plating (ENP) and spark plasma sintering (SPS) was used to determine the feasibility of fracture toughness improvement of ZrO2. Nano-grained yttria stabilized zirconia (YSZ) particles of 100nm average diameter were coated with about 1-5 nm of nickel coating by ENP. To reduce nano particle agglomeration throughout the ENP process; vigorous agitation with an ultrasonic horn was used. The coated powder was characterized using Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Transmission electron microscopy (TEM) to study the microstructure and coating characteristics. The coating was identified to be predominantly nickel and of 1 to 5 nm thickness. The plated powder was dried and consolidated by Spark plasma sintering (SPS) with sintering times significantly lower than used in conventional sintering processes. The solid compact was evaluated for mechanical properties. Hardness values were obtained from Vickers micro hardness indentations; fracture toughness was calculated by indentation-crack-length measurement and three-point bend test of notched samples; flexural strength was measured by 3-point bend tests. The measured hardness is comparable to the results found in the literatures. The coated and uncoated zirconia show significantly higher average fracture toughness compare to existing values.
"],"dc:identifier":["https://doi.org/7936/2amq-wx38","https://openscholarship.wustl.edu/eng_etds/431"],"dc:language":["English (en)"],"dc:rights":["I have not registered my thesis with the U.S. Copyright Office, but intend to later."],"dc:subject":["ceramic","zirconia","spark plasma sintering","electroless nickel coating","ductile phase toughening","Ceramic Materials","Engineering"],"dc:title":["Electroless Nickel Plating and Spark Plasma Sintering of nano ZrO2 for Mechanical Property Enhancement"],"thesis:degree_discipline":["Mechanical Engineering & Materials Science","McKelvey School of Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T06:13:05Z"}