Title: THERMAL CYCLIC BEHAVIOUR OF AIR PLASMA SPRAYED ZIRCONATE BASED COATINGS
1THERMAL CYCLIC BEHAVIOUR OF AIR PLASMA SPRAYED
ZIRCONATE BASED COATINGS
- BATCH MEMBERS G. AGORAMOORTHY
(80107144003), - M. ASWIN (80107144009),
- K. RAMKUMAR (80107144036),
- M. SURESH (80107144050),
- FINAL YEAR MECHANICAL ENGINEERING,
- AVCCE-MANNAMPANDAL.
- PROJECT GUIDE
- INTERNAL GUIDE EXTERNAL GUIDE
- Mr. A. Ramprakash, M.E., Prof. Dr. V.
Balasubramanian, - Asst Professor, Director, CEMAJOR,
- Dept of Mechanical Engg, Dept of Manufacturing
Engg, - A.V.C.College of Engg, Annamalai University,
- Mannampandal. Chidambaram.
2NATURE OF THE PROJECT WORK
- Project work Outside the campus.
- Location Plasma spraying laboratory,
- Centre for Material Joining and Research,
(CEMAJOR), - Dept of Manufacturing Engg,
- Annamalai University,
- Chidambaram.
3OBJECTIVES
- The project work is made on a thermal sprayed
materials to study and analyze the heat
withstanding capacity among the materials. - Analyzation involves
- Scanning Electron Microscopy (SEM testing)
- X-ray Diffractometer (XRD testing).
4SYNOPSIS
- Substrate used here INCONEL 800.
- Coating materials Lanthanum Zirconate and Yttria
stabilized zirconate. - Coating systems APS plasmatron (Atmospheric
Plasma Spray system, 40 kw) - And HVOF spray system (High Velocity Oxy Fuel
spray system).
5ABOUT THE SUBSTRATE
- The substrate used here is INCONEL 800, which is
a super alloy of austenitic nickel-chromium. - Composition
- It comprises of Nickel, Chromium, Iron,
Molybdenum, Niobium, Cobalt, Manganese, Copper,
Aluminium, Titanium, Silicon, Carbon, Sulfur,
Phosphorus, Boron. - Properties
- Oxidation and corrosion resistant.
- When heated, Inconel forms a thick, stable,
passivating oxide layer protecting the surface
from further attack.
6ABOUT THE SUBSTRATE (contd.,)
- Uses
- It is common in gas turbine blades, seals, and
combustors, - Turbocharger rotors and seals, Electric
submersible well pump motor shafts, - High temperature fasteners,
- Chemical processing and pressure vessels, Heat
exchanger tubing, steam generators in nuclear
pressurized water reactors.
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8ABOUT THE CERAMIC COATINGS
- Ceramic coatings used here are
- Lanthanum Zirconate and
- Yttria stabilized Zirconate.
- Yttria stabilized Zirconate
- Yttria-stabilized zirconate (YSZ) is a
zirconium-oxide based ceramic, in which the
particular crystal structure of zirconium oxide
is made stable at room temperature by an addition
of yttrium oxide. These oxides are commonly
called "zirconia" (ZrO2) and "yttria" (Y2O3).
9ABOUT THE CERAMIC COATINGS (contd.,)
- Applications of YSZ
- It is used
- As a refractory,
- As a thermal barrier coating in gas turbines,
- As the solid electrolyte,
- As a material for non-metallic knife blades,
produced by Boker and Kyocera companies., - YSZ doped with rare-earth materials can act as a
thermographic phosphor (Phosphor thermometry is
an optical method for surface temperature
measurement. The method exploits luminescence
emitted by phosphor material).
10ABOUT THE CERAMIC COATINGS (contd.,)
- Lanthanum Zirconate
- Lanthanum zirconate (La2Zr2O7, LZ) is a newly
proposed material for thermal barrier coatings
(TBCs). - Compared with the standard TBC material
yttria-stabilized zirconia (YSZ), LZ coating has
a lower thermal expansion coefficient, which
leads to higher stress levels in a TBC system. - Lanthanum Zirconate has been developed as a TBC
using Electron Beam Physical Vapour Deposition
(EB-PVD).
11ABOUT THE CERAMIC COATINGS (contd.,)
- TBCs deposited by EB-PVD exhibit a columnar grain
microstructure. - It is able to balance the difference in thermal
expansion between the base material and TBC
during thermal cycle and hence improve the TBC
lifetime.
12ABOUT THE MACHINING
- There are two processes involved in thermal
barrier coating process. They are - HVOF (High Velocity Oxy Fuel Spray system).
- APS (Atmospheric Plasma Spray system).
- HVOF
- A mixture of gaseous or liquid fuel and oxygen is
fed into a combustion chamber, where they are
ignited and combusted continuously. - The fuels can be gases (hydrogen, methane,
propane, propylene, acetylene, natural gas, etc.)
or liquids (kerosene, etc.).
13HVOF (contd.,)
- - The jet velocity at the exit of the barrel
(gt1000 m/s) exceeds the speed of sound. - - A powder feed stock is injected into the gas
stream, which accelerates the powder up to 800
m/s. - - The stream of hot gas and powder is directed
towards the surface to be coated. The powder
partially melts in the stream, and deposits upon
the substrate. - - The resulting coating has low porosity and
high bond strength. - - it is typically used to deposit wear and corrosi
on resistant coatings on materials due to
oxidation.
14HVOF
15HVOF
16HVOF
Welding torch
Substrate
17APS
- Atmospheric Plasma Spraying (APS) has been used
to deposit porous partially nano structured
ceramic coatings. - Initially a bond coating made is NiCrAlY
(Nickel-Chromium-Aluminium-yttrium) coating, - This is made by HVOF spray system to avoid
oxidation and to provide a greater bond strength
with the ceramic coatings.
18APS
19APS
Powder feeder
Feed motor
20APS
Welding electric torch
Substrate holding Fixture
21APS
22OVERALL PROCESS
- Initially the substrate is prepared by Sand
blasting process to remove impurities. - Sand blasting is essential to increase bond
strength between substrate and coating material. - After sand blasting, the substrate is acid
treated for removing organic contaminants. The
chemical used here is acetylene.
23OVERALL PROCESS (CONTD.,)
- After chemical treatment, a bond coating is made
on the substrate by High Velocity Oxy Fuel Spray
system. - The bond coating applied here is Ni-Cr-Al-Y
(Nickel-Chromium-Aluminium-Yttrium alloy powder). - This coating increases bond strength with the
ceramic coatings and it also reduces oxidation. - Then the ceramic coatings are applied on the
substrate by six various combinations using
Atmospheric Plasma Spray System.
24OVERALL PROCESS (CONTD.,)
- After coating of ceramic materials, Scanning
Electron Microscopy is made on the substrates to
analyse the bonding structure among the
substrates. - After SEM testing, the substrates are treated in
the furnace at various operating temperatures
(12000c, 12300c, 12500c) and quenched. - This process gets continued until the coating
material peeled off from the substrate.
25OVERALL PROCESS (CONTD.,)
- After the coating material get peeled off, the
substrates are again tested by Scanning Electron
Microscopy. - The results are observed and compared with the
previous results.
26COATING COMBINATIONS
- 350 µ YSZ 150 µ NiCrAlY BOND COATING.
- 350 µ LZ 150 µ NiCrAlY BOND COATING.
- (175 µ LZ 175 µ YSZ) 150 µ NiCrAlY BOND
COATING. - (150 µ LZ 150 µ YSZ) 100 µ (50 NiCrAlY 50
YSZ) POWDER 100 µ NiCrAlY BOND COATING. -
27COATING COMBINATIONS (CONTD.,)
- 5. 125 µ LZ 100 µ (50 LZ 50 YSZ) POWDER
125 µ YSZ 150 µ NiCrAlY BOND COATING. - 6. 100 µ LZ 100 µ (50 LZ 50 YSZ) POWDER
100 µ YSZ 100 µ (50 NiCrAlY 50 YSZ) POWDER
100 µ NiCrAlY BOND COATING.
28RESULTS AND DISCUSSIONS
- This project work has been carried out for about
3 months. - The overall physical work has been finished by
our team members and we are at the edge of our
analysation work. - We are awaiting for the results and conclusions.
29FUTURE SCOPE OF THE PROJECT
- The major factors that influences the future
scope of our project work, that we consider are
as follows - Increased life of the material (INCONEL 800),
against wear and corrosion. - Enhanced protection from dusts and flying
Aerosols. - Enhanced heat resistance and safety of the
material (INCONEL 800), such as turbine blades,
pressure vessels, high temperature vessels and so
on.
30PHOTOS AND VIDEOS
31THANK YOU