Upload
atinderbir-singh-deo
View
217
Download
0
Embed Size (px)
Citation preview
7/30/2019 316 l Stainless Steel
1/17
Effect of Surface TreatmentEffect of Surface Treatmenton Surface Characteristics ofon Surface Characteristics of
316L Stainless Steel316L Stainless Steel
Guna SelvadurayGuna Selvaduray11
and Steve Trigwelland Steve Trigwell22
11San Jose State UniversitySan Jose State University22NASA Kennedy Space CenterNASA Kennedy Space Center
Materials and Processes for Medical Devices ConferenceMaterials and Processes for Medical Devices ConferenceNovember 14~16, 2005November 14~16, 2005
Boston, MABoston, MA
7/30/2019 316 l Stainless Steel
2/17
22G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Presentation OutlinePresentation OutlineIntroductionIntroductionMotivationMotivationExperimental ProcedureExperimental ProcedureAnalytical TechniquesAnalytical Techniques
xxxxxxyyyyyy
zzzzzzConclusionsConclusionsfuture workfuture work
7/30/2019 316 l Stainless Steel
3/17
33G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
IntroductionIntroductionAISI 316L Stainless SteelAISI 316L Stainless Steel Ni (10~14%), Cr (16~18%), Mo (2~3%)Ni (10~14%), Cr (16~18%), Mo (2~3%) AusteniticAusteniticUsed widely in medical devicesUsed widely in medical devices Fracture fixation plates, screwsFracture fixation plates, screws IntramedullaryIntramedullary nailsnails StentsStents EtcEtc
ThermomechanicalThermomechanical/processing history affects/processing history affects Bulk propertiesBulk properties Surface propertiesSurface properties
7/30/2019 316 l Stainless Steel
4/1744
G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Surfaces & BiocompatibilitySurfaces & BiocompatibilityBiocompatibility affected by surfaceBiocompatibility affected by surfacecharacteristicscharacteristics Surface chemistrySurface chemistry Surface roughnessSurface roughness
Surface porositySurface porosity Surface thermodynamicsSurface thermodynamicsCritical surface tension (of solid phase)Critical surface tension (of solid phase)
Surface chargeSurface charge Others ??Others ??Chemical & mechanical processingChemical & mechanical processing
affects/changes surface characteristicsaffects/changes surface characteristics
7/30/2019 316 l Stainless Steel
5/17
55G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Previous StudiesPrevious StudiesRelatively large number of studies relatingRelatively large number of studies relating
various aspects of surfaces tovarious aspects of surfaces tobiocompatibilitybiocompatibilityPrimarilyPrimarily in vivoin vivoand/orand/or in vitroin vitroteststests
Wide variety of testing methods forWide variety of testing methods forbiocompatibilitybiocompatibility
Detailed correlation of effect of processingDetailed correlation of effect of processingon surface characteristics and subsequenton surface characteristics and subsequenteffect on biocompatibility still neededeffect on biocompatibility still needed
7/30/2019 316 l Stainless Steel
6/17
66G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
ObjectiveObjectiveInvestigate the effect of surface treatmentInvestigate the effect of surface treatment
on the surface characteristics and surfaceon the surface characteristics and surfacechemistry ofchemistry of NiTiNiTi, AISI 316L, Co, AISI 316L, Co--Cr alloysCr alloysRelate to biocompatibility and corrosionRelate to biocompatibility and corrosion
behaviorbehaviorThis work:This work:
Effect of mechanical polishing, electropolishingEffect of mechanical polishing, electropolishingand plasma treatment on surface roughness,and plasma treatment on surface roughness,surface chemistry and critical surface tensionsurface chemistry and critical surface tension
7/30/2019 316 l Stainless Steel
7/17
77G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Experimental ApproachExperimental ApproachMaterialsMaterials AISI 316LAISI 316L 19 mm x 19 mm x 0.73719 mm x 19 mm x 0.737
mm couponsmm coupons CleanedCleaned Composition verified byComposition verified byGCMSGCMS
Surface treatments:Surface treatments: Mechanical polishing (MP)Mechanical polishing (MP)
#1000#1000 SiCSiC paperpaper MP + Electropolishing (EP)MP + Electropolishing (EP)
63% H63% H33POPO44, 15% H, 15% H22SOSO44,,
22% DI H22% DI H22OO MP + Plasma treatmentMP + Plasma treatment
98% He, 2% O98% He, 2% O22 EP + Plasma treatmentEP + Plasma treatment
7/30/2019 316 l Stainless Steel
8/17
88G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
AnalysisAnalysisSurface Roughness: Atomic ForceSurface Roughness: Atomic Force
MicroscopyMicroscopySurface Chemistry: XSurface Chemistry: X--ray Photoelectronray Photoelectron
SpectroscopySpectroscopyDepth Profile: Auger ElectronDepth Profile: Auger ElectronSpectroscopySpectroscopyCritical Surface Tension:Critical Surface Tension: ZismanZisman PlotsPlots
7/30/2019 316 l Stainless Steel
9/17
99G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Surface RoughnessSurface Roughness -- 11
8.825.233.608.03Standard deviation ()
29.8314.0614.6632.15Roughness Average ()
MP+Plasma
EP+PlasmaEPMP
Mechanically polished surface Electropolished surface
7/30/2019 316 l Stainless Steel
10/17
1010G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Surface RoughnessSurface Roughness -- 22Electropolishing very effective inElectropolishing very effective in
reducing surface roughnessreducing surface roughnessElectropolishing improves surfaceElectropolishing improves surface
uniformityuniformityPlasma treatment had no observablePlasma treatment had no observableeffect on surface roughnesseffect on surface roughness
7/30/2019 316 l Stainless Steel
11/17
1111G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Counts
Binding Energy, (eV)537 535 533 531 529 527 525
8000
10000
12000
14000
16000
18000
20000
22000
24000
26000 O2
OH
O(H2O
)
Label BE (eV) FWHM Height Gauss Asymm Norm. Area Rel. AreaO2 529.97 1.48 16700.3 80.0% 0.0% 9575.02 59.9%OH 531.64 1.58 8283.31 80.0% 10.0% 5127.35 32.1%O(H2O) 532.72 1.56 2055.77 80.0% 15.0% 1282.52 8.0%
Oxygen
Me
chanicallypolished
Counts
Binding Energy, (eV)537 535 533 531 529 527 525
8000
10000
12000
14000
16000
18000
20000
22000
24000
26000
28000
30000
32000
34000
36000
38000
40000
42000
44000
46000
48000
50000
52000
O2
OH
O(H2O)
Label BE (eV) FWHM Height Gauss Asymm Norm. Area Rel. AreaO2 530.25 1.46 7441.4 100.0% 0.0% 3856.01 11.9%OH 531.37 1.59 36403.4 80.0% 10.0% 22689 70.0%O(H2O) 532.75 1.80 8364.91 80.0% 10.0% 5880.28 18.1%
Peak-Fit Baseline: 535.80 to 527.50 eVReduced Chi-Square: 2.479
Oxygen
Electropolished
XX--rayray
PhotoelectronPhotoelectronSpectroscopySpectroscopy
7/30/2019 316 l Stainless Steel
12/17
1212G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
1:5.881:1.821:1.711:2.10Cr:Fe Ratio1.33.714.63.8Fe Sat
15.710.712.117.4Fe-OOH
81.776.051.559.8Fe2O3
0.74.516.39.6FeO
0.65.15.69.4Fe
Fe
12.119.935.319.7Cr-OH
80.168.948.467.3Cr2O3
7.911.216.313.0CrCr
6.813.118.18.0O(H2O)
28.159.770.032.1O-H
65.127.211.959.9O=
O
2.42.71.70.5O-C=O
3.73.95.15.9COO-
4.53.95.35.9C=O
12.414.816.215.5C-O77.174.771.672.2C-C/C-H
C
MP+Plasma
EP+PlasmaEPMPBond Type
XX--rayray
PhotoelectronPhotoelectronSpectroscopySpectroscopy
7/30/2019 316 l Stainless Steel
13/17
1313G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
XPS ResultsXPS Results
--
11
Electropolishing:Electropolishing: OO22 in oxide formin oxide form OO22 in hydroxide formin hydroxide form
Cr as hydroxideCr as hydroxide Fe as metallic, FeFe as metallic, Fe22OO33, and hydroxide, and hydroxide Fe asFe as FeOFeO
7/30/2019 316 l Stainless Steel
14/17
1414G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
XPS ResultsXPS Results
--
22
Cr:FeCr:Fe ratioratio
Bulk: 1:3.63Bulk: 1:3.63After mechanical polishing: 1:2.10After mechanical polishing: 1:2.10After electropolishing: 1:1.71After electropolishing: 1:1.71
Enrichment of Cr on the surface enhanced byEnrichment of Cr on the surface enhanced byelectropolishingelectropolishingEffect of plasma treatment:Effect of plasma treatment: MP + Plasma treatment: 1:5.88MP + Plasma treatment: 1:5.88 EP + Plasma treatment: 1:1.82EP + Plasma treatment: 1:1.82
7/30/2019 316 l Stainless Steel
15/17
1515G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Auger Electron SpectroscopyAuger Electron Spectroscopy
0
2000
4000
6000
8000
10000
0 25 50 75 100 125 150
OFe
Ni
Cr
C
~ 35
AES depth profile of electropolished 316L stainless steel
7/30/2019 316 l Stainless Steel
16/17
1616G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
Auger Electron SpectroscopyAuger Electron Spectroscopy -- 22
Ni concentration on surface significantly lower thanNi concentration on surface significantly lower thanbulk concentration of 13.78%bulk concentration of 13.78%Electropolishing enhances surface Cr concentrationElectropolishing enhances surface Cr concentrationSurface oxide layer thickness ~ same, except for MPSurface oxide layer thickness ~ same, except for MP
+ Plasma+ Plasma
~ 75 ~ 35 ~ 35 ~ 40 Thickness
2533Ni
18161018Fe
10102016Cr
70696663O
MP+Plasma
EP+PlasmaEPMPElement
7/30/2019 316 l Stainless Steel
17/17
1717G. SelvadurayG. SelvaduraySJSUSJSUNovember 16, 2005November 16, 2005
ConclusionsConclusions
AES & XPS results consistentAES & XPS results consistent
Electropolishing enriches Cr concentration inElectropolishing enriches Cr concentration inthe surface oxide layerthe surface oxide layerSurface oxide layerSurface oxide layer is a combination of Feis a combination of Feand Cr oxides and hydroxidesand Cr oxides and hydroxidesSurface concentration of Ni ~ 3%Surface concentration of Ni ~ 3% -- muchmuch
lower than bulk concentration of 13.78%lower than bulk concentration of 13.78%Plasma treatment reducesPlasma treatment reduces Cr:FeCr:Fe ratio; doesratio; doesnot improve surface passivationnot improve surface passivation