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The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy / GANG LIU

Swansea University Author: GANG LIU

DOI (Published version): 10.23889/Suthesis.53058

Abstract

Nickel-based superalloy IN713C produced by investment casting method are used for turbine blade of turbocharger in modern vehicles. IN713C alloy possesses good strength, fatigue, creep and high temperature oxidation resistance that make the alloy suitable to be used in harsh service environment such...

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Published: Swansea 2019
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
Supervisor: Birosca, Soran
URI: https://cronfa.swan.ac.uk/Record/cronfa53058
first_indexed 2019-12-19T04:17:34Z
last_indexed 2025-03-27T06:38:41Z
id cronfa53058
recordtype RisThesis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2025-03-26T13:03:43.7693422</datestamp><bib-version>v2</bib-version><id>53058</id><entry>2019-12-18</entry><title>The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy</title><swanseaauthors><author><sid>fcf965cef4838cf6b2c9412b1f557ba7</sid><firstname>GANG</firstname><surname>LIU</surname><name>GANG LIU</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2019-12-18</date><abstract>Nickel-based superalloy IN713C produced by investment casting method are used for turbine blade of turbocharger in modern vehicles. IN713C alloy possesses good strength, fatigue, creep and high temperature oxidation resistance that make the alloy suitable to be used in harsh service environment such as in the heating part of turbocharger. However, this material suffers from microstructure and microtexture heterogeneity produced during solidification. This microstructure heterogeneity across the component will inevitably give rise to local stress and strain accumulation which may facilitate crack initiation and affect crack propagation. Fatigue, both LCF (Low Cycle Fatigue) and HCF (High Cycle fatigue) are the common failure modes of turbine blade component in turbocharger. It is of industrial and academic interests to identify and classify the features of fracture surface of each failure mode. The necessity of optimisation of fatigue property for the newly developed turbocharger component parts is becoming critical and a fundamental research for understanding fatigue deformation micromechanism and the influence of microstructure (dendrite structure, carbides / oxidised carbides, grain size, etc.) and microtexture (individual crystallographic orientation, cluster of grains, etc.) is required. In the current investigation, LCF and HCF fatigue tests are conducted on real turbine blades as wel as on bars produced via investment casting. Various microstructure characterisation tools were used to identify the deformation micromechanics during LCF and HCF fatigue conditions. The results showed that in real turbine blades where there are much less casting defects than in the testing bar, the fatigue crack initiated from blade surface and crack propagation process was mainly dominated by oxidation-assistant process with oxidised carbides during LCF test. During the late stage of crack propagation, the interdendrite area was found to deform differently from the surrounding area to accommodate accumulated strain heterogeneity. Whilst for HCF, facet was initiated from slip planes with the highest Schmid factor and assisted by small porosity in most cases. As for the fatigue tests conducted on test bars produced via investment casting, the dendrite structure played a vital role in crack propagation mechanism. Based on the observations throughout this study, a concept of &#x2018;crack propagation unit (CPU)&#x2019; was proposed. From this proposed micro deformation mechanism, a new perspective of Hall-Patch effect of small grain size in casting alloys (containing dendrite structure) was further elucidated duirng both LCF and HCF. Finally, solidification trials were performed to study the exact correlation between solidification cooling rate and microstructure evolution including grain size and structure, gamma prime, carbides and other phases.</abstract><type>E-Thesis</type><journal/><volume/><journalNumber/><paginationStart/><paginationEnd/><publisher/><placeOfPublication>Swansea</placeOfPublication><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic/><keywords>Superalloy, deformation micromechanism, microstructure, microtexture</keywords><publishedDay>31</publishedDay><publishedMonth>10</publishedMonth><publishedYear>2019</publishedYear><publishedDate>2019-10-31</publishedDate><doi>10.23889/Suthesis.53058</doi><url/><notes>A selection of third party content is redacted or is partially redacted from this thesis.</notes><college>COLLEGE NANME</college><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><supervisor>Birosca, Soran</supervisor><degreelevel>Doctoral</degreelevel><degreename>Ph.D</degreename><apcterm>Not Required</apcterm><funders/><projectreference/><lastEdited>2025-03-26T13:03:43.7693422</lastEdited><Created>2019-12-18T17:26:31.6393572</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Materials Science and Engineering</level></path><authors><author><firstname>GANG</firstname><surname>LIU</surname><order>1</order></author></authors><documents><document><filename>53058__16143__64eeaea5a4ea42cfb6cfa6579b52130d.pdf</filename><originalFilename>Liu_Gang_PhD_Thesis_Final_Redacted.pdf</originalFilename><uploaded>2019-12-18T18:11:14.6783826</uploaded><type>Output</type><contentLength>27497883</contentLength><contentType>application/pdf</contentType><version>Redacted version - open access</version><cronfaStatus>true</cronfaStatus><copyrightCorrect>true</copyrightCorrect></document></documents><OutputDurs/></rfc1807>
spelling 2025-03-26T13:03:43.7693422 v2 53058 2019-12-18 The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy fcf965cef4838cf6b2c9412b1f557ba7 GANG LIU GANG LIU true false 2019-12-18 Nickel-based superalloy IN713C produced by investment casting method are used for turbine blade of turbocharger in modern vehicles. IN713C alloy possesses good strength, fatigue, creep and high temperature oxidation resistance that make the alloy suitable to be used in harsh service environment such as in the heating part of turbocharger. However, this material suffers from microstructure and microtexture heterogeneity produced during solidification. This microstructure heterogeneity across the component will inevitably give rise to local stress and strain accumulation which may facilitate crack initiation and affect crack propagation. Fatigue, both LCF (Low Cycle Fatigue) and HCF (High Cycle fatigue) are the common failure modes of turbine blade component in turbocharger. It is of industrial and academic interests to identify and classify the features of fracture surface of each failure mode. The necessity of optimisation of fatigue property for the newly developed turbocharger component parts is becoming critical and a fundamental research for understanding fatigue deformation micromechanism and the influence of microstructure (dendrite structure, carbides / oxidised carbides, grain size, etc.) and microtexture (individual crystallographic orientation, cluster of grains, etc.) is required. In the current investigation, LCF and HCF fatigue tests are conducted on real turbine blades as wel as on bars produced via investment casting. Various microstructure characterisation tools were used to identify the deformation micromechanics during LCF and HCF fatigue conditions. The results showed that in real turbine blades where there are much less casting defects than in the testing bar, the fatigue crack initiated from blade surface and crack propagation process was mainly dominated by oxidation-assistant process with oxidised carbides during LCF test. During the late stage of crack propagation, the interdendrite area was found to deform differently from the surrounding area to accommodate accumulated strain heterogeneity. Whilst for HCF, facet was initiated from slip planes with the highest Schmid factor and assisted by small porosity in most cases. As for the fatigue tests conducted on test bars produced via investment casting, the dendrite structure played a vital role in crack propagation mechanism. Based on the observations throughout this study, a concept of ‘crack propagation unit (CPU)’ was proposed. From this proposed micro deformation mechanism, a new perspective of Hall-Patch effect of small grain size in casting alloys (containing dendrite structure) was further elucidated duirng both LCF and HCF. Finally, solidification trials were performed to study the exact correlation between solidification cooling rate and microstructure evolution including grain size and structure, gamma prime, carbides and other phases. E-Thesis Swansea Superalloy, deformation micromechanism, microstructure, microtexture 31 10 2019 2019-10-31 10.23889/Suthesis.53058 A selection of third party content is redacted or is partially redacted from this thesis. COLLEGE NANME COLLEGE CODE Swansea University Birosca, Soran Doctoral Ph.D Not Required 2025-03-26T13:03:43.7693422 2019-12-18T17:26:31.6393572 Faculty of Science and Engineering School of Engineering and Applied Sciences - Materials Science and Engineering GANG LIU 1 53058__16143__64eeaea5a4ea42cfb6cfa6579b52130d.pdf Liu_Gang_PhD_Thesis_Final_Redacted.pdf 2019-12-18T18:11:14.6783826 Output 27497883 application/pdf Redacted version - open access true true
title The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy
spellingShingle The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy
GANG LIU
title_short The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy
title_full The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy
title_fullStr The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy
title_full_unstemmed The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy
title_sort The effects of microstructure and microtexture generated during solidification on deformation micromechanism in IN713C nickel-based superalloy
author_id_str_mv fcf965cef4838cf6b2c9412b1f557ba7
author_id_fullname_str_mv fcf965cef4838cf6b2c9412b1f557ba7_***_GANG LIU
author GANG LIU
author2 GANG LIU
format E-Thesis
publishDate 2019
institution Swansea University
doi_str_mv 10.23889/Suthesis.53058
college_str Faculty of Science and Engineering
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hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Materials Science and Engineering{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Materials Science and Engineering
document_store_str 1
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description Nickel-based superalloy IN713C produced by investment casting method are used for turbine blade of turbocharger in modern vehicles. IN713C alloy possesses good strength, fatigue, creep and high temperature oxidation resistance that make the alloy suitable to be used in harsh service environment such as in the heating part of turbocharger. However, this material suffers from microstructure and microtexture heterogeneity produced during solidification. This microstructure heterogeneity across the component will inevitably give rise to local stress and strain accumulation which may facilitate crack initiation and affect crack propagation. Fatigue, both LCF (Low Cycle Fatigue) and HCF (High Cycle fatigue) are the common failure modes of turbine blade component in turbocharger. It is of industrial and academic interests to identify and classify the features of fracture surface of each failure mode. The necessity of optimisation of fatigue property for the newly developed turbocharger component parts is becoming critical and a fundamental research for understanding fatigue deformation micromechanism and the influence of microstructure (dendrite structure, carbides / oxidised carbides, grain size, etc.) and microtexture (individual crystallographic orientation, cluster of grains, etc.) is required. In the current investigation, LCF and HCF fatigue tests are conducted on real turbine blades as wel as on bars produced via investment casting. Various microstructure characterisation tools were used to identify the deformation micromechanics during LCF and HCF fatigue conditions. The results showed that in real turbine blades where there are much less casting defects than in the testing bar, the fatigue crack initiated from blade surface and crack propagation process was mainly dominated by oxidation-assistant process with oxidised carbides during LCF test. During the late stage of crack propagation, the interdendrite area was found to deform differently from the surrounding area to accommodate accumulated strain heterogeneity. Whilst for HCF, facet was initiated from slip planes with the highest Schmid factor and assisted by small porosity in most cases. As for the fatigue tests conducted on test bars produced via investment casting, the dendrite structure played a vital role in crack propagation mechanism. Based on the observations throughout this study, a concept of ‘crack propagation unit (CPU)’ was proposed. From this proposed micro deformation mechanism, a new perspective of Hall-Patch effect of small grain size in casting alloys (containing dendrite structure) was further elucidated duirng both LCF and HCF. Finally, solidification trials were performed to study the exact correlation between solidification cooling rate and microstructure evolution including grain size and structure, gamma prime, carbides and other phases.
published_date 2019-10-31T07:38:08Z
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score 11.059529

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