The presentation discusses the testing and inspection of turbine blades, which is critical to ensure safe and efficient turbine operation. It covers various inspection methods for turbine blades, such as visual inspection, dye penetrant testing, ultrasonic testing, and automated inspection systems. Non-destructive testing methods like magnetic particle inspection, ultrasonic testing, x-ray radiography, and thermography are explored in detail. The challenges of inspecting turbine blades and key considerations for blade maintenance are also summarized.

1. Department: Metallurgy Engineering
Subject: Metallurgical Operations Seminar
TITLE: (3) Testing and inspection of Turbine Blade
Name : Aditya Shende (220133121023)
Yash Shinde (220133121025)
GOVERNMENT ENGINEERING COLLEGE
Sector-28, GANDHINAGAR
GUIDED BY : DR. I B DAVE
PROF. D.V. MAHANT

2. Topicscovered in 1st presentation
 Introduction of investment casting and turbine blade
 Application of investment casting
1) Energy
2) Marine
3) Aerospace
4) Medical
5) Automotive
 Performance requirement of turbine blade
1) Complex cooling structure
2) Advanced Grain structure
3) Super alloys
 Structure of turbine blade
 Advantages and disadvantages of investment casting
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3. Topics covered in2nd presentation
 Material used for manufacturing
1) Super alloys
2) Stainless Steel
 Design Process
 Process of investment casting
 External and Internal profile of turbine blades
 Manufacturing Process
 Main issues of investment casting of turbine blade
1) Design and Geometry
2) Material Selection
3) Shell Building
4) Melting and Pouring
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4. Contents
1. Defects in Turbine Blade
2. How important to inspect small defect
3. ImportanceofTurbineBladeTestingandInspection
4. Inspection Methods for Turbine Blades
5. Automated turbine blade inspection (BOREINSPECT
system)
6. Non-Destructive Testing Methods (NDT)
7. Challenges in NDT testing of turbine blade
8. Key Considerations for Gas Turbine Blade Maintenance
9. FutureAdvancementsinTurbineBladeTesting
10. Summary
11. Reference
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5. • The proper testing and inspection of turbine blades is
critical for ensuring safe and efficient turbine operation.
• In this presentation, we will explore various methods of
testing and inspection for turbine blades, including visual
inspection techniques, non-destructive testing methods
(NDT), and more.
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6. Defects in Turbine Blade
Investment casting is a common way to manufacture turbine blades. However, this method
is not perfect and can lead to defects. These include shrinkage porosity, gas porosity, and
hot tears, all of which can negatively affect the performance of turbine blades.
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Porosity Detection
Porosity can be detected through visual inspection
and non-destructive testing methods, such as X-ray
radiography and ultrasonic testing.
Oxidation
High-temperature environments can cause oxidation, forming
detrimental oxide scales that reduce the blade's
resistance to corrosion and further degrade its performance.
Cavitation damage
Cavitation damage is caused by the collapse of cavities in the fluid.
It can be detected visually or through non-destructive testing such
as eddy current testing and magnetic particle inspection.

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Hot tears
Hot tears occur due to thermal stresses during investment
casting. They can be detected visually and through careful
inspection of casting microstructures.
Cracking
Thermal cycles and mechanical stresses can induce
cracks, which weaken the blade and can propagate,
eventually leading to catastrophic failure.

8. How important to inspect small
defect
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9. Importance of TurbineBlade Testing and
Inspection
• Testing and inspection of gas turbine bladesare vital
for identifying defects, ensuring optimal performance,
and preventing catastrophic failuresthat can lead to
costly downtime and repairs.
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10. Inspection Methods for Turbine Blades
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1
2
3
Visual Inspection
A comprehensive visual examination of the blade surface, leading to
the identification of visible defects like erosion, cracks, and
deformations.
Dye Penetrant Inspection
A technique involving the application of a dye penetrant, which
highlights cracks and defects by seeping into these areas, aiding in
their detection.
Ultrasonic Inspection
Utilizes sound waves to assess the internal quality of the blade,
providing information about hidden defects invisible to the naked
eye.

11. Automatedturbine blade inspection(BOREINSPECT
system)
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12. Non-Destructive Testing Methods (NDT)
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Magnetic Particle Inspection (MPI)
MPI uses magnetic fields and iron oxide
particles to detect surface and slightly
subsurface defects such as cracks. It is a
widely used and versatile testing method
but requires proper preparation of the
surface and can only detect ferromagnetic
materials.
Ultrasonic Testing (UT)
UT uses high-frequency sound
waves to detect subsurface defects
such as cracks, voids, and
inclusions. It provides accurate and
reliable results but requires skilled
operators and can be affected by
material properties and geometry.
X-ray Radiography
X-ray radiography uses X-rays to
produce images of the internal
structure of the turbine blade. It can
detect a wide range of defects but
requires additional safety precautions
due to the ionizing radiation involved.
Thermography
Thermography involves measuring
temperature differences on the surface of
the turbine blade using infrared cameras. It
can detect surface defects, heat-affected
zones, and thermal stress but is affected by
environmental conditions and requires
proper heating and cooling of the blade.

13. Challenges in NDT testing of turbine blade
1. Complex Geometry: Gas turbine blades often have intricate designs and
complex geometries, making it challenging to access and inspect all
areas using traditional NDT methods.
2. High Temperatures: Gas turbine blades operate at high temperatures,
which can limit the use of certain NDT techniques that are sensitive to
temperature variations.
3. Material Variability: Turbine blades are made from various materials,
including superalloys, which can have heterogeneous properties, making
it difficult to ensure consistent NDT results.
4. Cost and Time: Implementing advanced NDT techniques can be costly
and time-consuming, making it a trade-off between inspection quality
and production efficiency.
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14. Key Considerations for Gas Turbine Blade
Maintenance
1) Regular Inspections
Frequent assessments to identify and address defects early, preventing
their progression and mitigating the risk of catastrophic failure.
2) Advanced Monitoring Systems
Implementing cutting-edge sensors and real-time monitoring
technologies to track blade health, enabling proactive maintenance
strategies.
3) Material and Coating Innovations
Investing in advanced materials and coatings that enhance blade performance,
reduce degradation, and improve resistance to defects and environmental factors.
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15. Future Advancements in Turbine Blade
Testing
1. Advanced Materials: Researchers are exploring new materials, such as
ceramics and advanced composites, that can withstand higher temperatures
and pressures, leading to more efficient and durable turbine blades
2. Cooling Technologies: Enhanced cooling methods, like internal cooling
channels or innovative heat-resistant coatings, can help dissipate heat and
maintain blade integrity at extreme conditions.
3. Improved Coatings: Innovative coatings can provide better protection
against environmental factors and erosion, increasing blade longevity.
4. Additive Manufacturing: 3D printing technology allows for the creation of
complex geometries and customized designs, which can improve turbine
blade performance and reduce manufacturing costs.
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16. Summary
• Turbine blade defects can compromise safety and performance.
Testing and inspection are vital to detect these issues early.
Non-Destructive Testing (NDT) methods, like ultrasound and
radiography, are employed for inspection. Challenges in NDT
testing include reaching all areas and interpreting data. Key
maintenance considerations involve cleaning and monitoring,
and future advancements may include advanced NDT
techniques and predictive maintenance with data analytics.
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17. Reference
1. Non-Destructive Testing and Evaluation of Materials". R. S.
Sharpe. 2013.
2. "Inspection and Testing of Turbine Blades". J. Smith. 2012.
3. Investment Casting Defects". M. S. Petrov. 2015.
4. Vibration Testing and Modal Analysis of Turbine Blades". B.
Wang, 2016.
5. "Thermal Barrier Coatings for Gas Turbine Engines". D. R. Clarke,
2010.
6. Non-Destructive Testing Methods for Turbine Blades by T. Das et
al.
7. Advances in Turbine Blade Inspection and Maintenance by J. Lee
et al.
8. NDT Evaluation of Turbine Blades and Components-Literature
Review by S. Kumar et al.
9. Liu DX, Chen G et al (2003) Aero-engine: the heart of airplane.
Aviation Industry Press,Beijing (in Chinese)
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