CHEM02200704003 Nilamadhab Pandhy - Homi Bhabha National ...

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Chapter 5 was an increase in martensite peak intensity. The “ballistic effect” of ions implanted on the surface, can also induce shear deformation, and produce dislocations in fcc crystal structure which enhances the martensite peak character [159]. At highest dose of implantation (1×10 17 , 2.5×10 17 N + /cm 2 ) a singlet peak was observed at 42.7 o corresponding to the formation of chromium nitride [Cr 2 N (111)] phase [160], and furthermore the peaks at 44.7º [αFe(110)], 65° [αFe(200)], and 82.3° [´-Fe (211)] also disappeared [21]. 5.2. 4 Metallographic characterization The results for metallographic characterization of unimplanted, and nitrogen implanted 304L SS are shown in Fig. 5.4 [21]. (a) (b) (c) (d) Fig. 5.4: Optical micrograph of 304L SS in (a) Oxalic acid (b) Vilella’s reagent, (c) Murakami’s reagent, and (d) at a dose of 1×10 16 N + /cm 2 in Villela’s reagent [21].
Chapter 5 The unimplanted specimen (Fig. 5.4a) revealed austenite microstructure in oxalic acid medium. However, the presence of martensite phase, and any abnormal ferrite phase present could not be confirmed by etching with Vilella’s reagent, and Murakami’s reagent (Fig. 5.4b-c). The reason is dissolution of superficial layer of martensite, and ferrite layer in the as polished specimens during etching. As in the case of unimplanted specimen, no ferrite microstructure was observed, for implanted specimens also it was not observed. The martensite phase at lower dose of 1×10 16 N + /cm 2 could not be revealed metallographically because of unknown depth, and extent of martensite formation (Fig. 5.4d). Second important factor is that the extent of martensite formation is dependent on energy of implantation, dose rate, and type of ion implanted. The degree of martensite transformation is higher for heavier ions. Study carried out by Chayahara et al [161] to investigate martensite transformation on 304 SS by high energy (1.5 MeV) implantation of heavier ions (Au + ) using TEM has revealed fewer martensite grains. However, in the present study as the energy of implantation and mass of ion implanted are small, the martensite layer formed is very thin to reveal the microstructure metallographically. As the dose rate increases the martensite layer formation is also coupled with nitride formation [162], and this has been reflected by the disappearance of main as well as additional martensite peaks at 44.7º, 65°, and 82.3° at dose of 1×10 17 N + /cm 2 , 2.5×10 17 N + /cm 2 , respectively. The martensite area provides defects and nitride nucleation sites, and acts as sinks for nitrogen [162]. Thus, at higher doses the martensite microstructure could not be revealed metallographically [21]. 5.2. 5 X-ray photoelectron spectroscopy study The detailed analysis of the Cr2p 3/2 and N1s energy levels has been carried out by deconvoluting the high resolution regions by asymmetric peak fitting procedure. The data presented in Fig. 5.5a-b is from the dose of 1×10 17 N + /cm 2 after sputtering for 3 min corresponding to erosion of 6 nm from the surface. The binding energy shift of Cr-Cr bond corresponding to the
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2.3 Effect of alloying elements on
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4 C H A P T E R 4 73 # $%&' 4.1 In
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6.2.3.2 Open circuit potential vs.
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eprocessing can be recovered, and c
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The ex-situ study of passive film w
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Fig.3.10: Schematic of electrical e
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Fig.6.11: Polarization study of unc
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AISI: American Institute of Steel I
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Chapter 1 C H A P T E R 1 Spent Nuc
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Chapter 1 1.3 Challenges in spent n
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Chapter 1 corrosion resistance. The
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Chapter 1 choice of zirconium is du
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C H A P T E R2
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Chapter 2 temperature, (c) higher i
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Chapter 2 Chromium in excess of 12
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Chapter 2 2. 3 Effect of alloying e
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Chapter 2 The twins are identified
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Chapter 2 and at temperature around
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Chapter 2 of adsorption of oxygen o
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Chapter 2 transpassive dissolution
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Chapter 2 healing chromium oxide fi
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Chapter 2 their segregation to the
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Chapter 2 is intimately related to
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Chapter 2 in nature because the dis
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C H A P T E R3
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Chapter 3 3.1.1.2 Specimen preparat
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Chapter 3 ionized. However, differe
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Chapter 3 various industrial applic
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Chapter 3 In the present investigat
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Chapter 3 3.1.3.2 Atomic force micr
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Chapter 3 present on the surface fo
Page 70 and 71: Chapter 3 necessary condition is th
Page 72 and 73: Chapter 3 Y m is the sputter yield.
Page 74 and 75: Chapter 3 Fig. 3.7: Schematic of X-
Page 76 and 77: Chapter 3 rate of 10Å/min using 5
Page 78 and 79: Chapter 3 different doses of nitrog
Page 80 and 81: Chapter 3 The modulus of electroche
Page 82 and 83: Chapter 3 equivalent circuit as sho
Page 84 and 85: Chapter 3 reference electrode with
Page 86 and 87: Chapter 3 for understanding the pas
Page 88 and 89: C H A P T E R4
Page 90 and 91: Chapter 4 encountered by all materi
Page 92 and 93: Chapter 4 pitting, and intergranula
Page 94 and 95: Chapter 4 The ridged structure, and
Page 96 and 97: Chapter 4 nitric acid is that the b
Page 98 and 99: Chapter 4 Potential (V) Vs Ag/AgCl
Page 100 and 101: Chapter 4 4.2.3 In-situ electrochem
Page 102 and 103: Chapter 4 The surface morphologies
Page 104 and 105: Chapter 4 a b c d Opening up of gra
Page 106 and 107: Chapter 4 Intensity (Arbitrary unit
Page 108 and 109: Chapter 4 The chromium, and oxygen
Page 110 and 111: Chapter 4 Intensity (Arbitrary unit
Page 112 and 113: C H A P T E R5
Page 114 and 115: Chapter 5 elements, and often impar
Page 116 and 117: Chapter 5 5.2 Results and discussi
Page 118 and 119: Chapter 5 Presence of oxygen is due
Page 122 and 123: Chapter 5 formation of Cr 2 N was a
Page 124 and 125: Chapter 5 electrochemical environme
Page 126 and 127: Chapter 5 N + Dose E corr (mV vs. A
Page 128 and 129: Chapter 5 layer capacitance (C dl )
Page 130 and 131: Chapter 5 correlation between surfa
Page 132 and 133: Chapter 5 boundary dissolution was
Page 134 and 135: Chapter 6 C H A P T E R 6
Page 136 and 137: Chapter 6 193]. As a single phase c
Page 138 and 139: Chapter 6 particles range from 8×1
Page 140 and 141: Chapter 6 Results revealed that in
Page 142 and 143: Chapter 6 The change over from capa
Page 144 and 145: Chapter 6 The impedance parameters
Page 146 and 147: Chapter 6 Conc. Substrate condition
Page 148 and 149: Chapter 6 6.6a-d. The uncoated spec
Page 150 and 151: Chapter 6 (55.18°) respectively, w
Page 152 and 153: Chapter 6 OCP shifted in noble dire
Page 154 and 155: Chapter 6 The high phase angle over
Page 156 and 157: Chapter 6 Fig. 6.10d: Log f vs. Log
Page 158 and 159: Chapter 6 Fig. 6.11b: Polarization
Page 160 and 161: Chapter 6 Covalent aspect of lattic
Page 162 and 163: Chapter 6 As compared to uncoated s
Page 164 and 165: Chapter 6 6.2.3.2 Open circuit pote
Page 166 and 167: Chapter 6 Similarly, the plots for
Page 168 and 169: Chapter 6 for the duplex coating, a
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Chapter 6 Fig.6.16b: Polarization s
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Chapter 6 6.2.3.5 Morphological exa
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Chapter 7 C H A P T E R 7 The cha
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Chapter 7 1. Surface morphology exa
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Chapter 7 6 Duplex Ti-TiO 2 coated
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Chapter 7 EC-SPM study on effect
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[1] Baldev Raj, U. Kamachi Mudali,
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[37] G. Okamoto, T. Shibata, Corros
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[79] M. Moens, M. Van Craen, F.C. A
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[117] R.E.Williford, C.F.Windisch J
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[157] N. Mottu, M. Vayer, R. Erre,
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[197] M. Metikos Hukovic, M. Ceraj
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[19] H. H. Uhlig, Corros Sci, 19 (1
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[57] J. F. Ziegler, J. P. Biersack,
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[97] I. Betova, M. Bojinov, V. Kara
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[139] V. Ashworth, R. P. M. Procter
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[176] G. Frankel, G. Grundmeier, H.
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List of publications 1. Referred
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CHEM02200704003 Nilamadhab Pandhy - Homi Bhabha National ...

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