File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Microstructure, nickel suppression and mechanical characteristics of electropolished and photoelectrocatalytically oxidized biomedical nickel titanium shape memory alloy

TitleMicrostructure, nickel suppression and mechanical characteristics of electropolished and photoelectrocatalytically oxidized biomedical nickel titanium shape memory alloy
Authors
KeywordsMicrostructure
Nanoindentation
NiTi shape memory alloy
Photoelectrocatalytic oxidation
Titania film
Issue Date2009
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/actabiomat
Citation
Acta Biomaterialia, 2009, v. 5 n. 6, p. 2238-2245 How to Cite?
AbstractA new surface modification protocol encompassing an electropolishing pretreatment (EP) and subsequent photoelectrocatalytic oxidation (PEO) has been developed to improve the surface properties of biomedical nickel titanium (NiTi) shape memory alloy (SMA). Electropolishing is a good way to improve the resistance to localized breakdown of NiTi SMA whereas PEO offers the synergistic effects of advanced oxidation and electrochemical oxidation. Our results indicate that PEO leads to the formation of a sturdy titania film on the EP NiTi substrate. There is an Ni-free zone near the top surface and a graded interface between the titania layer and NiTi substrate, which bodes well for both biocompatibility and mechanical stability. In addition, Ni ion release from the NiTi substrate is suppressed, as confirmed by the 10-week immersion test. The modulus and hardness of the modified NiTi surface increase with larger indentation depths, finally reaching plateau values of about 69 and 3.1 GPa, respectively, which are slightly higher than those of the NiTi substrate but much lower than those of a dense amorphous titania film. In comparison, after undergoing only EP, the mechanical properties of NiTi exhibit an inverse change with depth. The deformation mechanism is proposed and discussed. Our results indicate that surface modification by dual EP and PEO can notably suppress Ni ion release and improve the biocompatibility of NiTi SMA while the surface mechanical properties are not compromised, making the treated materials suitable for hard tissue replacements. © 2009 Acta Materialia Inc.
Persistent Identifierhttp://hdl.handle.net/10722/139540
ISSN
2015 Impact Factor: 6.008
2015 SCImago Journal Rankings: 2.020
ISI Accession Number ID
Funding AgencyGrant Number
Program for New Century Excellent TalentsCET-06-0464
Natural Science Foundation of Jiangsu ProvinceBK2007515
National High-tech Program-863 Projects of China2006AA03Z445
Nippon Sheet Glass Foundation for Materials Science and Engineering (NSG Foundation)
Hong Kong Research Grants Council (RGC)
General Research Funds (GRF)CityU 112307
123708
City University of Hong Kong Strategic Research7002305
Funding Information:

The work described in this paper was supported by the Program for New Century Excellent Talents (NCET-06-0464) at the University of Ministry of Education of China, Natural Science Foundation of Jiangsu Province (Project No.: BK2007515), National High-tech Program-863 Projects of China (Project No.: 2006AA03Z445), Nippon Sheet Glass Foundation for Materials Science and Engineering (NSG Foundation) and Hong Kong Research Grants Council (RGC) General Research Funds (GRF) Nos. CityU 112307 and 123708 and City University of Hong Kong Strategic Research Grant (SRG) No. 7002305.

References

 

DC FieldValueLanguage
dc.contributor.authorChu, CLen_HK
dc.contributor.authorGuo, Cen_HK
dc.contributor.authorSheng, XBen_HK
dc.contributor.authorDong, YSen_HK
dc.contributor.authorLin, PHen_HK
dc.contributor.authorYeung, KWKen_HK
dc.contributor.authorChu, PKen_HK
dc.date.accessioned2011-09-23T05:51:27Z-
dc.date.available2011-09-23T05:51:27Z-
dc.date.issued2009en_HK
dc.identifier.citationActa Biomaterialia, 2009, v. 5 n. 6, p. 2238-2245en_HK
dc.identifier.issn1742-7061en_HK
dc.identifier.urihttp://hdl.handle.net/10722/139540-
dc.description.abstractA new surface modification protocol encompassing an electropolishing pretreatment (EP) and subsequent photoelectrocatalytic oxidation (PEO) has been developed to improve the surface properties of biomedical nickel titanium (NiTi) shape memory alloy (SMA). Electropolishing is a good way to improve the resistance to localized breakdown of NiTi SMA whereas PEO offers the synergistic effects of advanced oxidation and electrochemical oxidation. Our results indicate that PEO leads to the formation of a sturdy titania film on the EP NiTi substrate. There is an Ni-free zone near the top surface and a graded interface between the titania layer and NiTi substrate, which bodes well for both biocompatibility and mechanical stability. In addition, Ni ion release from the NiTi substrate is suppressed, as confirmed by the 10-week immersion test. The modulus and hardness of the modified NiTi surface increase with larger indentation depths, finally reaching plateau values of about 69 and 3.1 GPa, respectively, which are slightly higher than those of the NiTi substrate but much lower than those of a dense amorphous titania film. In comparison, after undergoing only EP, the mechanical properties of NiTi exhibit an inverse change with depth. The deformation mechanism is proposed and discussed. Our results indicate that surface modification by dual EP and PEO can notably suppress Ni ion release and improve the biocompatibility of NiTi SMA while the surface mechanical properties are not compromised, making the treated materials suitable for hard tissue replacements. © 2009 Acta Materialia Inc.en_HK
dc.languageengen_US
dc.publisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/actabiomaten_HK
dc.relation.ispartofActa Biomaterialiaen_HK
dc.subjectMicrostructureen_HK
dc.subjectNanoindentationen_HK
dc.subjectNiTi shape memory alloyen_HK
dc.subjectPhotoelectrocatalytic oxidationen_HK
dc.subjectTitania filmen_HK
dc.subject.meshBiocompatible Materials - chemistry-
dc.subject.meshElectrochemistry - methods-
dc.subject.meshNickel - chemistry-
dc.subject.meshPhotochemistry - methods-
dc.subject.meshTitanium - chemistry-
dc.titleMicrostructure, nickel suppression and mechanical characteristics of electropolished and photoelectrocatalytically oxidized biomedical nickel titanium shape memory alloyen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1742-7061&volume=5&issue=6&spage=2238&epage=2245&date=2009&atitle=Microstructure,+nickel+suppression+and+mechanical+characteristics+of+electropolished+and+photoelectrocatalytically+oxidized+biomedical+nickel+titanium+shape+memory+alloy-
dc.identifier.emailYeung, KWK:wkkyeung@hkucc.hku.hken_HK
dc.identifier.authorityYeung, KWK=rp00309en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1016/j.actbio.2009.01.046en_HK
dc.identifier.pmid19251496-
dc.identifier.scopuseid_2-s2.0-67349159344en_HK
dc.identifier.hkuros192171en_US
dc.identifier.hkuros172957-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-67349159344&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume5en_HK
dc.identifier.issue6en_HK
dc.identifier.spage2238en_HK
dc.identifier.epage2245en_HK
dc.identifier.isiWOS:000267307900043-
dc.publisher.placeNetherlandsen_HK
dc.identifier.scopusauthoridChu, CL=7404345713en_HK
dc.identifier.scopusauthoridGuo, C=7402496793en_HK
dc.identifier.scopusauthoridSheng, XB=7102570515en_HK
dc.identifier.scopusauthoridDong, YS=7403390573en_HK
dc.identifier.scopusauthoridLin, PH=7403225139en_HK
dc.identifier.scopusauthoridYeung, KWK=13309584700en_HK
dc.identifier.scopusauthoridChu, PK=36040705700en_HK

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats