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WSN 34 (2016) 34-50 EISSN 2392-2192

Nano-Structural Features Raman Spectra and New Trend of 3D-AFM Investigations for High

Performance Ni-Super-alloy

Khaled M Elsabawy12 N H Elbagoury23 1Materials Science Unit Chemistry Department Faculty of Science Tanta University

Tanta 31725 Egypt

2Metallurgy Laboratory Advanced Materials Department Central Metallurgical Research and

Development Institute (CMRDI) PO Box 87 Helwan Cairo Egypt

3Chemistry Department Faculty of Science Taif University 888 Alhawyah Taif City Saudi Arabia

E-mail address khaledelsabawyyahoocom ksabawyhotmailcom

ABSTRACT

The synthesized Ni-alloy was prepared via conventional casting technique under vacuum and

highly superheated treatment route The casting parameters such as solidification cooling rate (SCR)

was monitoring by both of AFM and SEM Micro-structural investigations within different spots in the

same sample indicated that γ matrix is the domain phase besides minor phases as MC carbides σ

phase and η phase which was observed to solidify in two forms as plate-like and blocky shape The

volume fraction (Vf) of σ and η phases was increased as the solidification cooling rate decreases 3D-

microstructural imaging map of the Ni-based super-alloy was constructed depending upon AFM-data

evaluating that the morphology of the alloy-surface is a function of casting parameters Furthermore

raman spectra of highly superheated casted Ni-based super-alloy was performed to confirm existence

of different phases recorded via SEM and EDX-elemental analysis with their corresponding different

vibrational modes such as Ni-O vibrating modes in the region 360-510 cm-1

and Mo-O vibrating mode

which lies at 1005 cm-1

Keywords Synthesis Casting Raman Spectra SEM AFM 3D-microstructre

World Scientific News 34 (2016) 34-50

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1 INTRODUCTION

The Ni -base super-alloy has a great attention of researchers and investigators due to

their industrial and manufacturing application as blades of powerful gas turbines (over 125

MW)

These blades work at critical conditions of creep corrosion and fatigue for more than

70000h Many of additives specially refractory elements like Mo W Ta Cr and Co were

added to prevent local hot corrosion [1-3] In spite of important role of most of Ni base super-

alloy in the high temperature performance limited data on microstructure and material

characterization are reported therefore a complete description of the effect of casting

parameters on the Ni base alloys is required [4-7] Ni base super-alloy is known to have a

multiphase microstructure consisting of a solid solution strengthened austenitic nickel γ

matrix bimodal γrsquo precipitate γ γrsquo eutectic carbides and a small amount of deleterious

phases such as δ σ η and laves [8-11] In some cases minor phases like η phase and σ phase

which usually form at solid state in super-alloys may form at the end of solidification owing

to the influence of composition The η phase has a hexagonal close-packed (hcp) structure and

has the basic stoichiometry of Ni3Ti while σ phase has a tetragonal topologically close-

packed (TCP) structure Both η and σ phases are generally considered as deleterious minor

phases by alloy designers as they usually pose negative impact on superalloysrsquo mechanical

properties Previous studies are focused in analyzing the precipitation mechanism of η and σ

phases in solid state in superalloys η phase may form either during casting or thermo

exposure process in nickel based superalloys Bouse has reported that η phase or platelet

phases formed in the as cast microstructure of alloys containing high percentages of Ti such

as IN792 Hf IN939 GTD111 and IN6203 [12] Other studies also reported the occurrence of

η phase at the periphery of the γ γrsquo eutectics [13-15]

Many researchers through laser raman spectroscopy (LRS) investigations suggest that

probability of existing species like oxides hydroxides oxy hydroxides nitrates nitrides

sulphates chlorides and oxy chlorides of Fe Cr and Ni could be present in the passive film

and surface layers of synthesized M-based-alloy [16-25] The contributions of other elements

apart from Ti W Al Mo and Co were not expected to be detected in surface layer since

their content in the alloy was very low to be detectable

The major goal of the present article firstly is investigating the effect of high

superheating treatment and cooling rates on the micro-structural parameters of different

phases existed (even those with low content) on the alloy bulk and their vibrational modes

detectable thoroughly raman spectroscopic analysis and secondly implementation of LRS

raman spectroscopy as qualitative tool to identify different phases which are present in the

nickel alloy matrix

2 EXPERIMENTAL

The Ni-based alloy used in this work was received as turbine blade scrap supplied from

a gas turbine power plant Table 1 shows the chemical composition of as-received alloy This

scrap was double melted and cast under vacuum using an induction vacuum furnace In the

second melt some amounts of alloying elements such as Ti Co Ta W were added to adopt

the chemical composition then a third melting was made to ensure melting and homogenous


-36-

distribution of all alloying elements in the heat Heats were made by melting 10 kg of turbine

blade scrap Pouring was carried out into an investment casting ceramic mold

The chemical composition of the prepared experimental polycrystalline Ni base

superalloy is shown in Table 1 Optical emission apparatus ARL3560OES as well as Ni base

software were used to determine the chemical composition of as-cast alloys

Table 1 Chemical composition of as cast Ni base superalloys

Elements

Alloy C Cr Mo W Ti Co Al Nb Ta Ni

Ni-Based-Alloy 013 1501 197 281 363 767 452 107 127 Bal

As cast (H) 054 1695 245 436 588 1048 149 010 186 Bal

Fig 1 The schematic Skelton of the produced castings indicating different solution treatment

solidification conditions


-37-

The microstructure of as-cast specimens was investigated by Zeiss light optical

microscope fitted with Hitachi digital camera as well as JOEL JSM-5410 Scanning Electron

Microscope (SEM) The specimens for microstructure examination were cut from the cast

ingots then ground polished and etched with 100 ml H2O + 50 ml HCl + 50 ml H2SO4 + 4 g

CuSO4 solution Studying the microanalysis and segregation for alloying elements was

performed using EDS in JEOL JSM5410 Samples were scanned on Analytical Scanning

Electron Microscopy for the Jeol JSM-63OLA and VEECO INNOVA -AFM with multi-

modes function USA Raman laser of samples were measured on the Bruker FT Raman with

laser source 50 mW

Figure 1 shows the schematic skelton of the produced castings indicating different

solidification conditions There are 2 castings the first one has high superheat named coarse

casting giving symbol (H) and the other one has low superheat called fine casting giving

symbol (L) Additionally each one consists of three sections thin intermediate and thick

referring to fast medium and slow cooling rates respectively

3 RESULTS amp DISCUSSION

3 1 SEM3D-AFM-Microstructure Analysis of Casted-Ni-Alloy

3 1 A At High Solidification Cooling Rate (HSCR)

Fig 2a displays the optical microscope image captured for casted Ni-super-alloy with

high solidification cooling rate (HSCR) It was observed that it consists of primary γ eutectic

γγrsquo MC carbides and minor phases in the interdendritic zones such as σ -phase and ɳ-phase

that has plate-like form with Ti-rich content (Ni3Ti) phase which symbolized by orange

squares These observations of existence of multi-phases are in full agreement with data

reported in [9-11]

It can be seen from Fig 2b the nodular and plate-like of σ and ɳ-phases that found in

interdendritic regions near eutectic γγrsquo The plate-like phase existed at the eutectic periphery

was found to be rich in both Ti and Ni and lower in both Cr and W as detected in EDX

analysis results given in Table 3 This plate-like phase is identified as Ti-rich (Ni3Ti) phase

The eutectic γγrsquo colonies found at the interdendritic zones in the as cast microstructure

specimen It is clear that the γγrsquo eutectic is distributed at dendrite boundaries often near

micro-pores showing that they are formed during the last stages of solidification The

approximate ratios (areaarea ratios) Vf of ɳ-phase that represented in orange squares was

found to be in between ~ 12-18 of captured image area in the case of high solidification

cooling rate (HSCR) Furthermore the average grain size of Ni-super-alloy was estimated

from Fig 2b and ranged in between 23-54 microm which is fully consistent with those reported

on literature [45] Fig 2c shows high resolution three dimensional AFM-image recorded for

Ni-super-alloy surface with HSCR applying tapping mode For hyperfine 3D-structure of the

surface the experimental data supplied from AFM-device was forwarded to visualize the 3D-

surface to be able to map the surface with maximum accuracy as possible see Figs 2de

Fig 2d displays 3D-mapping structure for very small area 035x035 microm of nickel-

superalloy It was noticeable that ~ 50 of the surface morphology has z-axis (heights)

ranged in between (026-65 microm represented by dark and pale blue) and only ~ 10 has the

heights higher than 65 microm One can indicate that as strengthen phase ratio increases these

heights will be increased and consequently increasing of ɳ- phase will lead to corresponding


-38-

increase in these heights This notification is confirmed as clear in Fig 2e such that the ratio

of heights area dark zones to the homogeneous Ni-surface blue coloration is nearly equal to ~

10-12 which is identical to the estimated ratio of σ and ɳ-phases as confirmed from SE-

micro-structural investigations with EDX-analyses see Table 2

Fig 2(a-c)

(2a) Optical micrograph captured for Ni-alloy with HSCR

(2b) SE-micrograph showing σ and ɳ-phases and γγrsquo eutectic zone at HSCR

(2c) 3D-AFM tapping mode image of Ni-super-alloy

EDX analysis was used to investigate the micro-segregation of the as cast

specimens as shown in Table 2 The partitioning coefficient krsquo was calculated to

characterize the degree of micro-segregation between dendrite core and

interdendritic areas represented by eutectic γγrsquo krsquo is the ratio between the element

composition in dendrite core and the composition of the same element in eutectic

γγrsquo zone


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Fig 2d 3D-AFM-visualized image of Ni-super alloy at HSCR

Fig 2e 2-D-vertical view image to map heights ratio of Ni-alloy

030031

032

033

034

0

2

4

6

8

10

12

14

16

18

20

22

24

26

030

031

032

033

Z-

Axi

s

Y -

Axi

s

X- Axis

0

3250

6500

9750

1300

1625

1950

2275

2600

030 031 032 033 034

030

031

032

033

0

3250

6500

9750

1300

1625

1950

2275

2600

X - Axis Micrometer

Y -

Axi

s M

icro

met

er


-40-

Table 2 EDX-elemental analysis of the micro-constituents in as cast alloys

Elements

Phase C Cr Mo W Ti Co Al Nb Ta Ni

η in as cast fine 019 431 084 117 1594 719 153 034 300 Bal

η in as cast coarse 189 572 190 237 1407 833 208 013 646 Bal

σ in as cast fine 031 3385 973 468 505 1115 070 004 120 Bal

σ in as cast coarse 078 3675 2037 1001 229 968 047 -- 345 Bal

MC in as cast fine 684 035 163 763 2335 017 -- 023 5699 Bal

MC in as cast coarse 635 126 193 801 2032 063 015 036 5671 Bal

Table 2 shows the partition coefficient of important elements in the

experimental Ni base superalloys used in this study There are two groups of

alloying elements according to the portioning coefficient The first group of

elements symbolized (G1) has krsquo higher than one such as W Mo Co and Cr These

elements segregate to the dendrite core during solidification

However the other group of elements symbolized as (G2) has krsquo lower than

one like Al Ti and Ta These elements of this group are preferably segregated to the

liquid during solidification process ultimately solidifying in interdendritic zones

3 1 B At Medium Solidification Cooling Rate (MSCR)


medium solidification cooling rate (MSCR) The same notifications was also observed such

as existing of multi-phases as primary γ eutectic γγrsquo MC carbides and minor phases in the

interdendritic zones such as ɳ-phase that has plate-like form with Ti-rich content (Ni3Ti)

phase which symbolized by orange squares The differences between HSCR and MSCR could

be summarized in the following points as clear in Fig 3b that Vf the plate-like form of σ and

ɳ-phases represented by yellow squares increase slightly to record ~ 22-28 area ratio at

expense of eutectic γγrsquo zones The increasing in the approximate ratios (areaarea ratios) Vf

of σ and ɳ-phase that represented in yellow squares was found to be ~ 10 extra than of that

found under HSCR Furthermore the average grain size of Ni-super-alloy was estimated from

Fig 3b and ranged in between 32-61 microm which is remarkably higher than with those

reported on literature [45] Fig 3c displays 3D-mapping structure for very small area

035x06 microm of nickel-superalloy It was noticeable that ~ 70 of the measured surface

morphology has z-axis (heights) with the following division (~ 40 of heights has 1 ndash 3 microm

and the rest 30 higher than 3 with maximum height 7 microm represented by orange and dark

orange color as clear in Fig 3c The increasing in the area ratio with heights is due to the

previously mentioned increasing of strengthen phases as σ and ɳ-phases plus M-carbides

phases


-41-

Fig 3(a-b)

(3a) Optical micrograph captured for Ni-alloy with MSCR

(3b) SE-micrograph showing ɳ-phase and γγrsquo eutectic zone at MSCR

Fig 3(c) 3D-AFM-visualized image of Ni-super alloy at MSCR

380385

390395

400405

410415

0

1

2

3

4

5

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7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-

3 1 C At Low Solidification Cooling Rate (LSCR)


low solidification cooling rate (LSCR) The same trend was also observed such as existing of

multi-phases as primary γ eutectic γγrsquo MC carbides and minor phases in the interdendritic

zones such as ɳ-phase that has plate-like form with Ti-rich content (Ni3Ti) phase which

symbolized by orange squares

The differences between HSCR and LSCR could be formulated in the following points

as clear in Fig 4b that area ratio (Vf) the plate-like form of σ and ɳ-phases represented by

yellow squares increase slightly to record maximum ~ 43 area ratio at expense of others

phases zones

The increasing in the approximate ratios (areaarea ratios) Vf of σ and ɳ-phase that

represented in yellow squares was found to be ~ 336 extra than of that found under HSCR

Furthermore the average grain size of Ni-super-alloy was estimated from Fig4b and ranged in

between 05-52 microm which is remarkably variated according to the casting parameters

specially cooling rates

Fig 4c shows 3D-mapping structure for small area 06x06 microm of nickel-superalloy It

was noticeable that ~ 100 of the measured surface morphology has z-axis (heights ) with

the following features (~ 26 of heights has 01-19 microm 28 from 19-356 microm 19 from

356 to 437 microm and the rest 27 higher than 437 with maximum height 6 microm respectively

as clear in Fig 4d and as a result the increasing in the Vf with heights is due to increasing of

strengthen phases as σ and ɳ-phases plus M-carbides phases which are maximum with low

solidification cooling rate (LSCR)

Fig 4a Optical micrograph captured for Ni-alloy with LSCR

Fig 4b SE-micrograph showing ɳ-phase and γγrsquo eutectic zone at LSCR


-43-

Fig 4c 3D-AFM-visualized image of Ni-super alloy at LSCR

Fig 4d 2-D-vertical view image to map heights ratio of Ni-super-alloy

01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-

In all Figs 2b 3b and 4b that show SE-micrograph there are two types of

carbides the MC blocky type carbides which are located inside the γ matrix as well

as at the grain boundaries The MC agglomerated carbides mainly consist of (Ta Ti)

C in addition to lower percentages of Nb and W as presented in Table 3 The other

type of carbides is the fine M23C6 carbides as with Cr in which Cr(III) is the basic

element (Cr23C6) which can be observed only at the grain boundaries as indicated

in Table 3

Table 3 Partition coefficient of major elements in cast Ni base superalloys

3 2 Laser Raman Spectroscopy

Fig 5a shows the laser raman spectra recorded for non-smothed casted Ni-alloy inside

the range 300-550 cmminus1

to identify different vibrational modes of nickel as major constituent

of Ni-alloy It was observed that the most common vibrating modes of Ni-O lie at 364 400

and 510 cmminus1

by additional to vibrating mode appears at 476 cm-1

which is revealed to Ni3O4-

phase These results are in full agreement with those reported by [18] Furthermore there are

some extra bands appear in Fig 4a like those lie at 309 379 446 461 and 519 cmminus1

which are

assigned as α- or β-Ni-OH vibrating modes as reported in [26]

To identify some of minor phases constituent in the interfacial layers of Ni-base super-

alloy another scanning of raman spectra was constructed in the range in between 800-1200

cm-1

as clear in Fig 5b It was obviously that there are multi-mixed vibrational modes

assigned as the following sequence

(i) blue circles assignment which lie at 819 858 875 940 and 952 cmminus1

are attributable to

CrIII-CrVI-O vibrational modes

(ii) vibrational mode lies at 451701 and 920 cm-1

is corresponding to Ti-O mode as

confirmed by Ramya et al [26]

(iii) vibrational mode lie at 667716 751 765 and 935 cm-1

is corresponding to W-O modes

(iv) vibrational mode lies at 1005 cm-1

is corresponding to Mo-O vibrating mode and finally

(v) vibrational mode lie at 364 499 510 1085 cm-1

which are belonging to Ni-O modes

These results are consistent with those reported by [18-21] who investigated nickel-

stainless alloy namely 316LN SS alloy by laser raman spectroscopy and they characterized

different vibrating modes existed in the corroded interfacial surface of Ni-alloy

The present results can be understood on the basis that Ni-based alloy could be

passivated and form some metal-oxides according to the composition of the interfacial layers

which means that Ni-based-alloy vibrating modes are preparative conditions dependent

Elements

Part Coeff Al Ti Cr Co Mo Ta W Ni

krsquo in as cast G1 095 050 124 121 116 052 165 1013



-45-

Fig 5a Raman spectra recorded for casted ndashnon-smoothed Ni-superalloy showing different

vibrational modes of Ni-O moiety

Fig 5b Raman spectra recorded for casted ndashnon-smoothed Ni-superalloy showing different

vibrational modes of Cr-O Ti-O and Mo-O moieties

300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4

Ni-OH vibrating modesIn

ten

sity

Raman Shift cm-1

Ni-O vibrational mode

800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-

Fig 5c Raman spectra recorded for casted ndashnon-smoothed Ni-superalloy showing different

vibrational modes of W-O moiety

In the case of compounds of chromium on the passivated surface of Ni-alloy they will

exist as Cr(III) or Cr(VI) The moderate intensity peak at 860 cmminus1

was attributed to Cr(III)

and Cr(VI) mixed phase [27-32] which was slightly red shifted by a few wave numbers

(around 871-885 cmminus1

) Also a weak peak around 520-570 cmminus1

was due to Cr2O3 [29]

which was diminished and overlapped with the frequencies of nickel oxides thus indicating

the possibility of existing in the form of NiCr2O4

Apart from the presence of chromium and Titanium oxides one could expect

contributions of Ni as NiO at the surface layer The reported value for the heat of formation of

NiO was found to be equal minus24319 kJ molminus1

[33] Cr2O3 has more negative heat of formation

ie minus105858 kJ molminus1

Hence Cr would preferentially get oxidized and nickel was expected

to be segregated at the oxide interface [34]

Garke et al [35] showed that there was only a small amount of nickel in the oxidemetal

interface where there was no change in the nickel concentration and the nickel was in

elemental state in the segregated zone Since LRS cannot trace out individual elements [36]

the presence of elemental Ni could not be detected Even if all the Ti W and Cr get oxidized

paving way to nickel oxidation still it was difficult to sense the presence of traces of

elemental-nickel due to the limited sensitivity of LRS Fig 5c shows the raman spectra

recorded in specific range 660-780 cm-1

to identify the vibrational modes of W-O

660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-

Fig 6a Raman spectra recorded for casted ndashsmoothed Ni-superalloy showing diminishing of most

common vibrational modes

Fig 6b Raman spectra recorded for casted ndashsmoothed Ni-superalloy in specific range of

measurements 2000-2300 cm-1

showing hydroxylated metals vibration modes

500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-

As clear in Fig 4c there are bands lie at 668 713 745 and 772 cm-1

by additional to that

appears in Fig 4b at 935 cm-1

these bands were observed also with Frost at al with some

wavenumbers shift [37] who reported that W-O vibrating modes includes ν1 symmetric

stretching mode of the W-O units at around 926 cmminus1

And two bands at 765 and 751 cmminus1

These bands are thought to be associated with the antisymmetric and symmetric Ag modes

respectively of the WO2 Multiple low intensity bands are observed in the 740-780 cmminus1

region The bands observed at 767 and 747 cmminus1

are assigned to be ν3(Bg) and ν3(Eg) modes

Fig 6ab show the raman spectra recorded for smoothed Ni-alloy sample It was

noticeable that most of common raman vibration modes throughout the whole range were

diminished as clear in Fig6a only few vibration modes appeared in the range (2000-2300 cm-

1) as showed in Fig 6b these bands did not previously published in literature and in our

speculations it could be attributable to hydroxylated metal oxide while metal could be Ni W

Ta Al or Ti according to the chemical constitution of Ni-alloy

4 CONCLUSIONS

The conclusive remarks inside this article could be briefed in the following points

1- The casting parameters such as solidification cooling rate (SCR) has very important role

in microstructure features such that as the volume fraction (Vf) of σ and η phases

increased as the solidification cooling rate decreases and vice versa

2- Volume fraction (Vf) of the plate-like form of σ and ɳ-phases are recording maximum ~

43 area ratio at expense of others phases zones at LSCR

3- SE-microscopy proved that Metal carbide (MC) blocky type carbides are located inside

the γ matrix as well as at the grain boundaries

4- Laser Raman spectroscopy (LRS) could be used as qualitative technique to identify

different phases constituents that present in the interfacial layer of the Ni-alloy surface

since

a- Ni-O vibrational modes lie at 364 499 510 1085 cm-1

b- vibrational mode lies at 1005 cm-1

is corresponding to Mo-O vibrating mode

c- vibrational modes lie at 451701 and 920 cm-1

are corresponding to Ti-O modes

d- vibrational mode lies at 819 858 875 940 and 952 cm-1

are attributable to CrIII-CrVI-O

vibrational modes

e- vibrational mode lie at 667 716 751 765 and 935 cm-1


References

[1] B Gyu Choi In Soo Kim Doo Hyun Kim Chang Young Jo Materials Science and

Engineering A 478 (2008) 329

[2] Seyed Abdolkarim Sajjadi Said Nategh Roderick IL Guthrie Materials Science and


[3] CT Liua J Ma XF Sun Journal of Alloys and Compounds 491 (2010) 522


-49-

[4] F Long YS Yoo CY Jo SM Seo YS Song T Jin ZQ Hu Materials Science and


[5] SA SAjjadi SM Zebarjad RIL Guthrie M Isac Materials Processing Technology

175 (2006) 376

[6] M Pouranvari A Ekrami AH Kokabi Alloys and Compounds 461 (2008) 641

[7] Alain Jacques Frederic Diologent Pierre Caron Pierre Bastie Materials Science and


[8] Robert A Kupkovits Daniel J Smith Richard W Neu Procedia Engineering 2 (2010)

687

[9] M Pouranvari A Ekrami AH Kokabi Materials Science and Engineering A 490

(2008) 229

[10] Huang Xuebing Kang Yan Zhou Huihua Zhang Yun Hu Zhuangqi Materials Letters

36 (1998) 210

[11] Zhaokuang Chu Jinjiang Yu Xiaofeng Sun Hengrong Guan Zhuangqi Hu Materials

Science and Engineering A 527 (2010) 3010

[12] GK Bouse in RD Kissinger D J Deye DL Anton AD Cetel MV Nathal TM

Pollock (Eds) Superalloys 1996 The Minerals Metals and Materials Society Warrendale

PA USA 1996 163-172

[13] W R Sun JH Lee SM Seo SJ Choe ZQ Hu Mater Sci Technol 15 (1999) 1221

[14] BG Choi IS Kim DH Kim CY Jo Mater Sci Eng A 478 (2008) 329

[15] SM Seo IS Kim JH Lee CY Jo H Miyahara and K Ogi Metall Mater Trans A

38 (2007) 883

[16] J Gui and TM Devine Corrosion Science 32 (1991) 1105

[17] DS Dunn MB Bogart CS Brossiaand and GA Cragnolino Corrosion 56 (2000)

470

[18] DLA de Faria S Venacircncio Silva and MT de Oliveira Journal of Raman Specroscopy

28 (1997) 873

[19] KN Jallad and D Ben-Amotz Material Science and Technology 17 (2001) 479

[20] R Balasubramaniam AV Ramesh Kumar and P Dillmann Current Science 85 (2003)

1546

[21] F Dubois C Mendibide T Pagnier F Perrard and C Duret Corrosion Science 50

(2008) 3401

[22] T Kamimura and M Stratmann Corrosion Science 43 (2001) 429

[23] D Cook Corrosion Science 47 (2005) 2550

[24] D Neff L Bellot-Gurlet P Dillmann S Reguer and L Legrand Journal of Raman

Specroscopy 37 (2006) 1228


-50-

[25] M Yamashita H Miyuki Y Matsuda H Nagano and T Misawa Corrosion Science 36

(1994) p 284

[26] S Ramya T Anita H Shaikh and RK Dayal Corrosion Science 52(6) (2010) 2114-

2121

[27] JD Ramsey and Richard L McCreery Corrosion Science 46 (2004) 1729

[28] TL Sudhesh L Wijesinghe and DJ Blackwood Applied Surface Science 253 (2006)

1006

[29] S Kikuchi K Kawauchi M Kurosawa H Honjho and T Yahishita Analytical

Sciences 21 (2005) 197

[30] JD Ramsey and RL McCreery Journal of the Electrochemical Society 146 (1999)

4076

[31] J Zhao L Xia A Sehgal D Lu RL McCreery and GS Frankel Surface and

Coatings Technology 140 (2001) 51

[32] JE Maslar WS Hurst WJ Bowers JH Hendricks MI Aquino and I Levin Applied

Surface Science 180 (2001) 102

[33] In RC Weast Editor Handbook of Chemistry and Physics (65th ed) CRC Press Boca

Raton FL (1984)

[34] X Tian Ricky KY Fu Lianwei Wang and Paul K Chu Materials Science and

Engineering A316 (2001) p 200

[35] B Garke C Edelmann R Gunzel and J Brutscher Surface Coating Technology 93

(1997) p 318

[36] NB Colthup LH Daly and SE Wiberley Introduction to Infrared and Raman

Spectroscopy (third ed) Academic Press New York (1990)

[37] R L Frost L Duong and M Weier Spectrochimica Acta Part A Molecular and

Biomolecular Spectroscopy 60(8-9) (2004) 1853-1859

( Received 14 December 2015 accepted 28 December 2015 )


-35-

1 INTRODUCTION

The Ni -base super-alloy has a great attention of researchers and investigators due to

their industrial and manufacturing application as blades of powerful gas turbines (over 125

MW)

These blades work at critical conditions of creep corrosion and fatigue for more than

70000h Many of additives specially refractory elements like Mo W Ta Cr and Co were

added to prevent local hot corrosion [1-3] In spite of important role of most of Ni base super-

alloy in the high temperature performance limited data on microstructure and material

characterization are reported therefore a complete description of the effect of casting

parameters on the Ni base alloys is required [4-7] Ni base super-alloy is known to have a

multiphase microstructure consisting of a solid solution strengthened austenitic nickel γ

matrix bimodal γrsquo precipitate γ γrsquo eutectic carbides and a small amount of deleterious

phases such as δ σ η and laves [8-11] In some cases minor phases like η phase and σ phase

which usually form at solid state in super-alloys may form at the end of solidification owing

to the influence of composition The η phase has a hexagonal close-packed (hcp) structure and

has the basic stoichiometry of Ni3Ti while σ phase has a tetragonal topologically close-

packed (TCP) structure Both η and σ phases are generally considered as deleterious minor

phases by alloy designers as they usually pose negative impact on superalloysrsquo mechanical

properties Previous studies are focused in analyzing the precipitation mechanism of η and σ

phases in solid state in superalloys η phase may form either during casting or thermo

exposure process in nickel based superalloys Bouse has reported that η phase or platelet

phases formed in the as cast microstructure of alloys containing high percentages of Ti such

as IN792 Hf IN939 GTD111 and IN6203 [12] Other studies also reported the occurrence of

η phase at the periphery of the γ γrsquo eutectics [13-15]

Many researchers through laser raman spectroscopy (LRS) investigations suggest that

probability of existing species like oxides hydroxides oxy hydroxides nitrates nitrides

sulphates chlorides and oxy chlorides of Fe Cr and Ni could be present in the passive film

and surface layers of synthesized M-based-alloy [16-25] The contributions of other elements

apart from Ti W Al Mo and Co were not expected to be detected in surface layer since

their content in the alloy was very low to be detectable

The major goal of the present article firstly is investigating the effect of high

superheating treatment and cooling rates on the micro-structural parameters of different

phases existed (even those with low content) on the alloy bulk and their vibrational modes

detectable thoroughly raman spectroscopic analysis and secondly implementation of LRS

raman spectroscopy as qualitative tool to identify different phases which are present in the

nickel alloy matrix

2 EXPERIMENTAL

The Ni-based alloy used in this work was received as turbine blade scrap supplied from

a gas turbine power plant Table 1 shows the chemical composition of as-received alloy This

scrap was double melted and cast under vacuum using an induction vacuum furnace In the

second melt some amounts of alloying elements such as Ti Co Ta W were added to adopt

the chemical composition then a third melting was made to ensure melting and homogenous


-36-







Elements



As cast (H) 054 1695 245 436 588 1048 149 010 186 Bal




-37-









laser source 50 mW














reported in [9-11]






















-38-





Fig 2(a-c)









γγrsquo zone


-39-



030031

032

033

034

0

2

4

6

8

10

12

14

16

18

20

22

24

26

030

031

032

033

Z-

Axi

s

Y -

Axi

s

X- Axis

0

3250

6500

9750

1300

1625

1950

2275

2600

030 031 032 033 034

030

031

032

033

0

3250

6500

9750

1300

1625

1950

2275

2600

X - Axis Micrometer

Y -

Axi

s M

icro

met

er


-40-


Elements


































phases


-41-

Fig 3(a-b)




380385

390395

400405

410415

0

1

2

3

4

5

6

7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-36-







Elements



As cast (H) 054 1695 245 436 588 1048 149 010 186 Bal




-37-









laser source 50 mW














reported in [9-11]






















-38-





Fig 2(a-c)









γγrsquo zone


-39-



030031

032

033

034

0

2

4

6

8

10

12

14

16

18

20

22

24

26

030

031

032

033

Z-

Axi

s

Y -

Axi

s

X- Axis

0

3250

6500

9750

1300

1625

1950

2275

2600

030 031 032 033 034

030

031

032

033

0

3250

6500

9750

1300

1625

1950

2275

2600

X - Axis Micrometer

Y -

Axi

s M

icro

met

er


-40-


Elements


































phases


-41-

Fig 3(a-b)




380385

390395

400405

410415

0

1

2

3

4

5

6

7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-37-









laser source 50 mW














reported in [9-11]






















-38-





Fig 2(a-c)









γγrsquo zone


-39-



030031

032

033

034

0

2

4

6

8

10

12

14

16

18

20

22

24

26

030

031

032

033

Z-

Axi

s

Y -

Axi

s

X- Axis

0

3250

6500

9750

1300

1625

1950

2275

2600

030 031 032 033 034

030

031

032

033

0

3250

6500

9750

1300

1625

1950

2275

2600

X - Axis Micrometer

Y -

Axi

s M

icro

met

er


-40-


Elements


































phases


-41-

Fig 3(a-b)




380385

390395

400405

410415

0

1

2

3

4

5

6

7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-38-





Fig 2(a-c)









γγrsquo zone


-39-



030031

032

033

034

0

2

4

6

8

10

12

14

16

18

20

22

24

26

030

031

032

033

Z-

Axi

s

Y -

Axi

s

X- Axis

0

3250

6500

9750

1300

1625

1950

2275

2600

030 031 032 033 034

030

031

032

033

0

3250

6500

9750

1300

1625

1950

2275

2600

X - Axis Micrometer

Y -

Axi

s M

icro

met

er


-40-


Elements


































phases


-41-

Fig 3(a-b)




380385

390395

400405

410415

0

1

2

3

4

5

6

7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-39-



030031

032

033

034

0

2

4

6

8

10

12

14

16

18

20

22

24

26

030

031

032

033

Z-

Axi

s

Y -

Axi

s

X- Axis

0

3250

6500

9750

1300

1625

1950

2275

2600

030 031 032 033 034

030

031

032

033

0

3250

6500

9750

1300

1625

1950

2275

2600

X - Axis Micrometer

Y -

Axi

s M

icro

met

er


-40-


Elements


































phases


-41-

Fig 3(a-b)




380385

390395

400405

410415

0

1

2

3

4

5

6

7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-40-


Elements


































phases


-41-

Fig 3(a-b)




380385

390395

400405

410415

0

1

2

3

4

5

6

7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-41-

Fig 3(a-b)




380385

390395

400405

410415

0

1

2

3

4

5

6

7

37

38

39

40

4142

43

Z A

xis

Y -

Axi

s M

icro

met

er

X Axis

0

08750

1750

2625

3500

4375

5250

6125

7000


-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-42-










phases zones
















-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-43-



01

23

4

5

6

0

1

2

3

4

5

6

-2

0

24

6

Z -

Axi

s M

icro

met

er

(Y - Axis) M

icrometer

X - Axis Micrometer

-05000

03125

1125

1938

2750

3563

4375

5188

6000

0 1 2 3 4 5 6

-2

0

2

4

6

-05000

03125

1125

1938

2750

3563

4375

5188

6000

X - Axis Micrometer

Y -

Axis

M

icrom

ete

r


-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-44-







in Table 3







and 510 cmminus1





which are




cm-1




are attributable to

















Elements





-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-45-





300 350 400 450 500 55000000

00002

00004

00006

00008

00010

510400

499

364

Ni3O4


ten

sity

Raman Shift cm-1


800 850 900 950 1000 1050 1100 1150 120000001

00002

00003

00004

00005

00006

00007

935 cm-1

W-O mode

920 cm-1

Ti-O

CrIII-O Modes

CrVI-O Modes

Ni-O

1085 cm-1

952 cm-1

875 cm-1

858 cm-1

819 cm-1

1005 cm-1

Mo-O vibrating mode

Inte

nsi

ty

Raman Shift cm-1


-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-46-



























660 680 700 720 740 760 780000020

000025

000030

000035

000040

000045

772 cm-1

745 cm-1

713 cm-1

668 cm-1

Inte

nsit

y

Raman Shift cm-1

W-O vibrating modes


-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-47-






500 1000 1500 2000 2500 3000 3500 4000

000

005

010

015

020

025

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy

2000 2050 2100 2150 2200 2250 2300

015

016

017

018

019

020

021

022

Inte

nsit

y

Raman Shift cm-1

Smoothed Ni-Alloy


-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-48-


















4 CONCLUSIONS











since








vibrational modes



References







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-49-




175 (2006) 376





687


(2008) 229


36 (1998) 210





PA USA 1996 163-172




38 (2007) 883



470


28 (1997) 873



1546


(2008) 3401






-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318







-50-


(1994) p 284


2121



1006


Sciences 21 (2005) 197


4076






Raton FL (1984)




(1997) p 318






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