Erosion

1. Erosion wear behaviour of plasma sprayed NiCrSiB/Al2O3
composite coating
 Ayyappan Susila Praveena,
,
 J. Sarangana,
,
 S. Suresha, ,
,
 J. Siva Subramanianb,
Abstract
In this work, 60 wt.% NiCrSiB–40 wt.% Al2O3 composite coating was produced on AISI
304 substrate material using the atmospheric plasma spraying technique. The coating
surface has been characterised using a scanning electron microscope (SEM), optical
microscope and X-ray diffractometer (XRD). The microhardness, porosity, density and
surface roughness of the coating were measured. The adhesion strength of the coating
was measured using pull off adhesion tester. The erosion behaviour of plasma sprayed
coating was studied at 450 °C using hot air jet erosion testing machine. The erosion rate
of coated and uncoated samples was evaluated at 30° and 90° erodent impact angles.
The SEM images of the eroded samples were taken to analyse the erosion mechanism.
The test results reveal that the coating protects the substrate at both 30° and 90° impact
angles.
Synergistic effect of ultrasonic cavitation erosion and
corrosion of WC–CoCr and FeCrSiBMn coatings prepared
by HVOF spraying
 Sheng Honga, ,
,
 Yuping Wua, ,
,
 Jianfeng Zhanga
,
 Yugui Zhengb
,
 Yuan Zhengc
,
 Jinran Lind
Abstract
The high-velocity oxygen-fuel (HVOF) spraying process was used to fabricate
conventional WC–10Co–4Cr coatings and FeCrSiBMn amorphous/nanocrystalline
coatings. The synergistic effect of cavitation erosion and corrosion of both coatings was

2. investigated. The results showed that the WC–10Co–4Cr coating had better cavitation
erosion–corrosion resistance than the FeCrSiBMn coating in 3.5 wt.% NaCl solution.
After eroded for 30 h, the volume loss rate of the WC–10Co–4Cr coating was about 2/5
that of the FeCrSiBMn coating. In the total cumulative volume loss rate under cavitation
erosion–corrosion condition, the pure cavitation erosion played a key role for both
coatings, and the total contribution of pure corrosion and erosion-induced corrosion of
the WC–10Co–4Cr coating was larger than that of the FeCrSiBMn coating. Mechanical
effect was the main factor for cavitation erosion–corrosion behavior of both coatings.
Optimization and erosion wear response of NiCrSiB/WC–
Co HVOF coating using Taguchi method
 Ayyappan Susila Praveena,
,
 J. Sarangana,
,
 S. Suresha, ,
,
 B.H. Channabasappab,
Abstract
In this work, high velocity oxy-fuel (HVOF) thermal spraying was used to develop
65 wt% NiCrSiB–35 wt% WC–Co coatings on AISI 304 stainless steel substrate.
Taguchi method was taken to optimize the spray parameters like oxygen flow rate, fuel
flow rate, powder feed rate and standoff distance to obtain better erosion resistance at
90° impact angle. Standoff distance and powder feed rate were identified as the highly
contributing parameters on the erosion wear loss. The important sequence of the spray
parameter is standoff distance>powder feed rate>fuel flow rate>oxygen flow rate. The
combination of 220 lpm of oxygen flow rate, 65 lpm of fuel flow rate, 28 g/min of powder
feed rate and 300 mm of standoff distance was identified as the optimum condition for
minimum erosion wear loss. The microstructure of the optimized coating was
characterized using Scanning Electron Microscope (SEM) equipped with Energy
dispersive spectroscopy (EDS), Optical microscope (OM), and X-Ray Diffraction (XRD).
The microhardness, porosity and surface roughness of the coating was also measured.
Finally, erosion wear testing of the optimized coating was conducted at 30°, 60° and 90°
impact angle using hot air jet erosion testing machine. The SEM images of the erodent
samples were taken to analyse the erosion mechanism.

3. Erosion wear behaviour of plasma sprayed NiCrSiB/Al2O3 composite coating
Praveen A S
J. Sarangan
S. Suresh
J. Siva Subramanian
ABSTRACT
In this work, 60 wt.% NiCrSiB–40 wt.% Al2O3 composite coating was produced on AISI 304
substrate material using the atmospheric plasma spraying technique. The coating surface has
been characterised using a scanning electron microscope (SEM), optical microscope and X-ray
diffractometer (XRD). The microhardness, porosity, density and surface roughness of the coating
were measured. The adhesion strength of the coating was measured using pull off adhesion
tester. The erosion behaviour of plasma sprayed coating was studied at 450 °C using hot air jet
erosion testing machine. The erosion rate of coated and uncoated samples was evaluated at 30°
and 90° erodent impact angles. The SEM images of the eroded samples were taken to analyse the
erosion mechanism. The test results reveal that the coating protects the substrate at both 30° and
90° impact angles.
Erosion wear behaviour of plasma sprayed NiCrSiB/Al2O3 composite coating (PDF Download
Available). Available from:
https://www.researchgate.net/publication/279518459_Erosion_wear_behaviour_of_plasma_spr
ayed_NiCrSiBAl2O3_composite_coating [accessed Feb 15, 2016].
Evaluation of hot corrosion behavior of plasma sprayed
scandia and yttria co-stabilized nanostructured thermal
barrier coatings in the presence of molten sulfate and
vanadate salt
 Mohammad Reza Loghman-Estarkia, , ,
,
 Mehrdad Nejatib
,
 Hossein Edrisc
,

4.  Reza Shoja Razavia
,
 Hossein Jamalia
,
 Amir Hossein Paksereshtb
Abstract
In this study, the substrates of Inconel 738-LC superalloy were first sprayed with an
NiCrAlY bondcoat and then with a nanostructured scandia (3.6 mol%) and yttria
(0.4 mol%) co-stabilized zirconia (4SYSZ) topcoat by air plasma spraying (APS). Hot
corrosion studies of plasma sprayed thermal barrier coatings (TBCs) were conducted in
45 wt% Na2SO4 + 55 wt% V2O5 molten salt at 910 °C for 300 h. The results show that
the failure of this TBC occurred in bondcoating layer due to the formation of mixed oxide
(NiO, NiAl2O4 and NiCr2O4) in this layer.
Solid particle erosion of standard and advanced thermal
barrier coatings
 F. Cernuschia
,
 C. Guardamagnaa, ,
,
 S. Capellia
,
 L. Lorenzonia
,
 D.E. Mackb
,
 A. Moscatellic
Abstract
The state-of-the-art of the thermal barrier coatings (TBCs), used to protect hot path
components from combustion gases, is represented by yttria (partially) stabilized
zirconia (YPSZ). Combustion and cooling technology improvements in combination with
higher turbine inlet temperature imply that the standard YSZ approaches have certain
limitations due to sintering and phase transformations at elevated temperatures.
Moreover under high thermal loading early failure of the coating occurs due to attack by
calcium–magnesium–alumino-silicate (CMAS) deposits inducing cracking, spallation
and delamination of the coating. Alternative refractory materials development, with
higher performances than YSZ, was the objective of the UE project H2IGCC: within this
project the erosion resistance of porous, dense segmented YPSZ TBCs and innovative
TBCs, featured with a bilayer structure, has been tested at impingement angles of 30°
and 90°, representative for particle impingement on trailing and leading edges of gas
turbine blades and vanes, respectively. Alumina powders with grain size representative
of sand and fly ashes, respectively were chosen as the erodent.

5. A better erosion resistance of dense segmented TBCs regardless of experimental
conditions was observed, whereas one of the new bilayer coating, due to its peculiar
micro-structure, showed a very interesting erosion resistance, at least with fine erosion
particles.
Ultrasonic cavitation erosion of high-velocity oxygen-fuel
(HVOF) sprayed near-nanostructured WC–10Co–4Cr
coating in NaCl solution
 Sheng Honga, ,
,
 Yuping Wua, ,
,
 Jianfeng Zhanga
,
 Yugui Zhengb
,
 Yujiao Qina
,
 Jinran Lina
Abstract
The high-velocity oxygen-fuel (HVOF) spraying process was used to prepare near-
nanostructured WC–10Co–4Cr coating. The cavitation erosion behavior and
mechanism of the coating in 3.5 wt.% NaCl solution were analyzed in detail. The results
showed that the amorphous phase and WC grain were present in the coating. The
cavitation erosion resistance of the coating was about 1.27 times that of the stainless
steel 1Cr18Ni9Ti under the same testing conditions. The effects of erosion time on the
microstructural evolution were discussed. It was revealed that cracks initiated at the
edge of pre-existing pores and propagated along the carbide–binder interface, leading
to the pull-out of carbide particle and the formation of pits and craters on the surface.
The main failure mechanism of the coating was erosion of the binder phases, brittle
detachment of hard phases and formation of pitting corrosion products.
Degradation mechanism for high temperature erosion in surface
modified IN718 superalloy
PreviewFull text HTML
PDF
Access options

6. DOI:
10.1179/1743294414Y.0000000377
K. G. Thirugnanasambanthama & S. Natarajan*ab
Abstract
Nickel based superalloy, Inconel 718, is one of the main candidates for high temperature applications
such as air craft, land base and marine turbines. This technical paper deals with high temperature erosion
behaviour and its mechanism of Al2O3–40TiO2 (A40T) coating on Inconel 718 alloy. Al2O3–
40TiO2 coatings through plasma spray method were made on Inconel 718. The erosion behaviour of the
A40T coating was studied using hot air jet erosion experiments at 800°C with varying parameters like
angle of impingement and erodent velocity. Characterisation of the samples was carried out using SEM
images, and mechanisms of erosion are discussed. Images (SEM) reveal that the A40T coating exhibit
ductile and brittle behaviour by ploughing and network cracking with grain chipping at 45° angle of
impingement, while at 90°, it is brittle behaviour by network cracking and grain ejection. This investigation
concludes that A40T coating on IN718 provides good erosion resistance at elevated temperatures.
The Influence of Temperature on Erosion Resistance of Carbide Coatings Deposited by
APS Method
Pawel Sosnowy *, Marek Góral, Slawomir Kotowski, Grzegorz Hanula, Jakub Gwizdała, Jakub
Drzał, Marcin Kobylarz, Przemysław Borowski, Rafał Gargała
The carbide coatings are widely used for wear and erosion protection of different materials. In
present paper the WC/Co coatings were deposited by a single-cathode Sulzer Metco F-4 plasma gun.
The microstructure and thickness measurements were conducted. The erosion test was conducted
using a Koechler Air Jet Errosion tester at the temperature of up to 500o
C. The procedure was similar
to ASTM G76 standard. Changes in erosion resistance of coating into different temperature were
observed.
High erosion-oxidation performance of Fe-based Nb or V
containing multi-component alloys with Co addition at
1173 K
 Kenta Kusumotob
,
 Kazumichi Shimizub
,
 Xinba Yaera, ,
,
 Hiroya Harab
,
 Kazuhiro Tamurab
,
 Hideki
Abstract

7. High temperature erosion-oxidation behavior of Fe-based Nb or V containing multi-
component alloys with Co addition is investigated at 1173 K. High temperature erosion
tests and oxidation tests are conducted to determine both erosion and oxidation
behaviors. Oxide scales are detected on the surfaces with 5V–10Nb and 5V–10Co
showing superior erosion-oxidation resistance at 1173 K. The erosion rate is high in V-
containing samples without Co due to the occurrence of vanadium oxide attack. Whilst,
with increasing of Co content, the erosion rate is reduced, indicating the addition of Co
is an effective counter-measure. In Nb-containing samples on the other hand, oxidation
is successfully controlled by the formation of a composite oxide layer regardless of the
presence of Co, thereby reducing the erosion losses.
Effects of post annealing on the microstructure,
mechanical properties and cavitation erosion behavior of
arc-sprayed FeNiCrBSiNbW coatings
 Jinran Lina, ,
,
 Zehua Wanga, ,
,
 Pinghua Linb
,
 Jiangbo Chenga
,
 Xin Zhanga
,
 Sheng Honga
Abstract
FeNiCrBSiNbW coatings were fabricated via arc spraying process and were
subsequently annealed at 450, 550 and 650 °C for 1 h to study the effect of annealing
treatment on the microstructure, mechanical properties and cavitation erosion behavior.
Microstructure was studied using scanning and transmission electron microscopy. The
results showed that oxides, fine crystalline particles and borides were formed after
annealing at 650 °C. With increasing annealing temperature, the coatings showed
reductions in porosity and fracture toughness, and an increase in microhardness. The
cavitation erosion behavior of the coatings was investigated in distilled water. The
results showed that the cavitation erosion resistance of the coatings decreased with
increasing annealing temperature, and the as-sprayed coating exhibited the best
cavitation erosion resistance among the four kinds of coatings. This was attributed to
the good fracture toughness, high amorphous phase content and the absence of oxides
in the as-sprayed coating.

8. Effect of Al-deposition on erosion resistance of plasma
sprayed thermal barrier coating
 Xiao-feng ZHANGa, b
,
 Ke-song ZHOUa, b, ,
,
 Shu-juan DONGc
,
 Wei XUb
,
 Jin-bing SONGb
,
 Min LIUb
Abstract
A columnar Al film was firstly deposited on the top of 7%Y2O3–stabilized zirconia (7YSZ)
ceramic coating in thermal barrier coating (TBC) system by magnetron sputtering. A
vacuum treatment was then carried out at 700 °C for 1 h and 900 °C for 5 h to improve
the erosion resistance of Al-deposited TBC. A α-Al2O3 layer was in situ synthesized on
the top of 7YSZ coating via vacuum heat treatment. The microstructure evolution of Al-
deposited TBC illustrated that a loose surface-layer and a dense sub-layer formed on
the top of 7YSZ coating after vacuum treatment. The phase structures of the as-sprayed
TBC and the Al-deposited TBC after vacuum heat treatment were characterized by X-
ray diffraction (XRD) and transmission electron microscope (TEM) assisted with focused
ion beam (FIB). Particulate erosion resistances of the as-sprayed TBC and treated TBC
were compared at room temperature. In addition, erosion mechanism and schematic
diagram were proposed. The results show that the Al-deposited TBC after vacuum heat
treatment has better particulate erosion resistance than the as-sprayed one.
Effect of ultrasonic cavitation erosion on corrosion
behavior of high-velocity oxygen-fuel (HVOF) sprayed near-
nanostructured WC–10Co–4Cr coating
 Sheng Honga, ,
,
 Yuping Wua, ,
,
 Jianfeng Zhanga
,
 Yugui Zhengb
,
 Yujiao Qina
,
 Jinran Lina
Abstract
The effect of ultrasonic cavitation erosion on electrochemical corrosion behavior of high-
velocity oxygen-fuel (HVOF) sprayed near-nanostructured WC–10Co–4Cr coating in
3.5 wt.% NaCl solution, was investigated using free corrosion potential, potentiodynamic

9. polarization curves and electrochemical impedance spectroscopy (EIS) in comparison
with stainless steel 1Cr18Ni9Ti. The results showed that cavitation erosion strongly
enhanced the cathodic current density, shifted the free corrosion potential in the anodic
direction, and reduced the magnitude of impedance of the coating. The impedance of
the coating decreased more slowly under cavitation conditions than that of the stainless
steel 1Cr18Ni9Ti, suggesting that corrosion behavior of the coating was less affected by
cavitation erosion than that of the stainless steel.
Hot corrosion behavior of LaTi2Al9O19 ceramic exposed to
vanadium oxide at temperatures of 700–950 °C in air
 Xin Zhoua, b, c
,
 Zhenhua Xuc
,
 Limin Hec
,
 Jiaying Xua, b
,
 Binglin Zoua, ,
,
 Xueqiang Caoa, ,
Abstract
Hot corrosion behavior of LaTi2Al9O19 ceramic exposed to V2O5 at 700–950 °C were
investigated in order to better understand the corrosion resistance of LaTi2Al9O19 as a
promising thermal barrier coating material. Results indicate that the degradation
processes were significantly temperature dependent. At 700 °C, AlVO4, LaVO4 and
TiO2were the main corrosion products, while AlVO4 partially decomposed at 800 °C to
form θ-Al2O3 and α-Al2O3. After exposure to 950 °C, V2O5 reacted with LaTi2Al9O19 to form
LaVO4, α-Al2O3 and TiO2 as final corrosion products. The hot corrosion mechanisms
were further discussed based on the phase diagrams of V2O5–Al2O3, V2O5–La2O3 and
V2O5–TiO2 systems.
High-Temperature Oxidation and Hot
Corrosion Studies on NiCrAlY Coatings
Deposited by Flame-Spray Technique
 Nidhi Rana
 , Manas Mohan Mahapatra
 , R. Jayaganthan
 , Satya Prakash
The NiCrAlY coatings deposited by flame-spray technique on the superalloy substrate were oxidized in
the presence of air and Na2SO4 + V2O5 salt at 900 °C for 100 cycles. The kinetics of oxidation showed
that the coatings deposited by flame-spray technique possess better oxidation resistance compared with

10. coatings deposited by high-velocity oxy fuel (HVOF)-sprayed technique. The oxidized coatings were
further characterized by XRD, FESEM/EDS, and x-ray mapping techniques. The mechanisms of the
oxidation and hot corrosion were substantiated by analyzing the results obtained from the various
characterization techniques.
Erosion–corrosion behaviour of Ni–20Cr plasma coating in actual
boiler environment
S. B. Mishra
*a
& S. Prakash
b
Abstract
Erosion–corrosion is encountered in a large variety of engineering industries. In such environments,
protective coatings are used. In this investigation, erosion–corrosion of the Ni–20Cr coating on nickel and
iron based superalloys has been investigated by subjecting them to the boiler of coal fired thermal power
plant at the temperature zone of 540°C for 1000 h duration. The erosion–corrosion kinetics of the plasma
sprayed Ni–20Cr coating on different superalloys has been investigated. XRD, SEM with EDS and EPMA
have been used to analyse the eroded–corroded products along the surface and cross-section. Main
phases identified in all the Ni–20Cr coated superalloys after exposure are NiO, Cr2O3, Al2O3 and SiO2.
Aluminium has penetrated from the bond coat to the top coat along the splat boundaries. Oxides of
chromium, nickel and aluminium are recognized as protective oxides for boiler environment. The probable
mechanism of attack for Ni–20Cr coating in the given boiler environment is discussed.
Comparison of hot corrosion behavior of nanostructured
ScYSZ and YSZ thermal barrier coatings in the presence of
molten sulfate and vanadate salt
 M.R. Loghman-Estarkia, ,
,
 R. Shoja Razavia
,
 H. Edrisb
,
 S.R. Bakhshia
,
 M. Nejatic
,
 H. Jamalia
Abstract
Hot corrosion behavior of nanostructured scandia (3.6 mol%) and yttria (0.4 mol%)
stabilized zirconia (4ScYSZ) and yttria stabilized zirconia (4YSZ) were investigated.
Thus, duplex TBCs (thermal barrier coatings), composed of a bond coat (NiCrAlY) and
a top coat (4ScYSZ or 4YSZ), were deposited on the IN738LC Ni-based supperalloy by
atmospheric plasma spraying (APS). Hot corrosion studies of plasma sprayed TBCs
were conducted in 45 wt% Na2SO4+55 wt% V2O5 molten salt at 910 °C for different
times. Based on the results, it was revealed that ScYSZ coating has more hot corrosion

11. resistance than YSZ coatings. Moreover, the mechanisms of degradation of both TBCs
under corrosion salt were suggested.
Erosion–corrosion resistance of electroplated Co-Pd film
on 316L stainless steel in a hot sulfuric acid slurry
environment
 Sirui Lia
,
 Yu Zuoa, ,
,
 Pengfei Jub
Abstract
A Co-Pd film was deposited on 316L stainless steel by electroplating. The erosion–
corrosion behavior of the Co-Pd plated samples in hot sulfuric acid solution with
SiO2particles was investigated. The results showed that there was a significant
synergistic effect between erosion and corrosion. At higher stirring speed, even in such
strong corrosive environment the erosion–corrosion rate of Co-Pd plated samples was
controlled mainly by the erosion resistance. The erosion–corrosion resistance of pure
Pd plated sample decreased rapidly with increasing stirring speed, whereas that of Co-
Pd plated sample kept almost stable under the tested conditions due to the high micro-
hardness and good corrosion resistance of the film.
Evaluation of erosion-corrosion resistanceof some
detonation gun sprayedcoatings on grade A-1 boiler steel
in a coal fired boiler
Balwinder Singh, Ankit Jain, Vikas Chawla
Abstract
The present investigation is made to evaluate the erosion-corrosion (E-C) behavior of detonation gun
sprayed Cr3C2-NiCr (75%-25%), Stellite-6 (St-6) and satellite-21 (St-21) coatings on ASTM SA210 Grade
A1 boiler tube steel in the actual environment of coal fired boiler. The experimental studies are performed in
the super heater zone of a coal fired boiler at GNDTP, Bathinda, where the temperature is around 900°C and
the study is carried out up to 1000 Hrs (10 cycles each of 100 Hr in boiler followed by 1 Hr cooling at
ambient temperature). All the selected bare and coated samples are exposed to actual environment of an
industrial boiler. An approach has been made to develop the properties in the substrate material to
withstand high temperature hot corrosion and erosion along with comparative study of each coating
developed. It was found that the coating on the boiler steel has provided the necessar y protection to the
base metal. The coated ASTM-SA210 Grade A1 steel has been able to resist erosion-corrosion at higher
temperature for a longer period than the uncoated steel.

12. Development Of Erosion Corrosion Resistant HVOF Sprayed Cr3C2 Nicr Coatings For Boiler Tube
Steels Operating At Elevated Temperatures
Bhatia, Rakesh Singh, Hazoor