This mini project depicts the possibility of medical scanning to determine the defects in casting after reconstruction. The results are less significant but this ultimately predicts the importance of industrial scanner in finding and reconstructing casting defects.

1. INTROSPECTING CASTING DEFECTS IN
METAL CASTED TURBINE BLADE
THROUGH CT SCANNING
Presented by-Akriti Belbase

2. CONTENTS
CT SCANNING
WHAT IS CT SCANNING?
HOW DOES THIS WORK?
MEDICAL VS INDUSTRIAL CT
SCANNING
ARTIFACTS
3D SLICER
3D SLICER TOOLS
3D SLICER EXTENSIONS
OBJECTIVE
METHODOLOGY
3D RECONSTRUCTION
RESULTS
WORK REMAINING
RECOMMENDATION

3. CT SCANNING
• A medical imaging procedure that
uses a motorized x-ray source that
rotates around the circular opening
of a donut-shaped structure
• Numerous 2D images are
extrapolated to 3D images
mathematically

4. Medical CT scanner is not suitable for large dense objects such as steel parts or
concrete blocks, due to the limit of 120–130 kV for most such systems. Since higher
X-ray voltages are possible with industrial CT systems , the penetrating power of
Industrial CT scanner is high
Medical CT SCANNING INDUSTRIAL CT SCANNING

5. ARTIFACTS
• It is any divergence between
the reconstructed values
produced in a CT image and
the actual sample value
based on its material density
and geometry
The fur like appearance in the picture are streaks artifacts

6. OBJECTIVE
• To introspect the possibility of CT Scanning
and 3D reconstruction to find casting defects
in metal casted turbine blade

7. METHODOLOGY
3D scanning the turbine blade
Exporting the DICOM file in 3d slicer
Optimization for removal of artifacts
Reconstruction of the 3D model
3D printing

8. 3D RECONSTRUCTION
• 3D SLICER MODULES
• 3D SLICER TOOLS

9. RESULTS
Volume Reconstruction
red part is the object and the gray streaks are the artifacts.
Metal Casted Turbine Blade
• The Turbine blade was mild
steel casted and coated with
aluminum

10. DISCUSSIONS
1. Artifacts
• The rotation generated repetitive artifacts that
come to look as streak.
• This is due to the low voltage used to penetrates X
ray. The X –Rays are less powerful and they get
entirely captured inside the metal instead of
penetrating to give the image.
How to avoid artifacts ?
Artifacts cannot be removed entirely if we are using Medical
CT scanner to scan the part.
But it can be reduced by application of filters and other tools
in Slicer.
Other software can also be used because in the past when
Industrial scanners were not developed, medical
scanners only did the job.
Changing the voltage (Increasing) at the time of scan will
reduce the artifacts

11. 2. Problem in Reconstruction of thin
portion of Blade .
• The function used was the threshold function of
highest intensity. If we decrease the intensity we
can model the missing part separately.
• It could be possible that changing the alignments
can reconstruct the missing part as well
Solution
1. Using different intensity level to mode the
missing part differently.
2. Changing the alignment of the metal blade while
CT scanning
Missing part indicated by white circle

12. 3. Can Casting Defects be detected with
certainty?
• No, It wont be detected with certainty. And not
all defects will be detected.
• Slicer is a software used for medical purpose to
reconstruct the part . It works with quality and
comparison.
• The industrial scanner works with quantity and
accuracy.
However, some errors like hotspots, difference in
density and surface errors can be studied
using Slicer.
• Exploring the Slicer extensions like
Free Grow Cut for removing artifacts
• Developing new segment for the
missing part.
• Exploring other software for
dimensional accuracy
WORK REMAINING

13. References
https://www.startradiology.com/the-basics/x-rayct-technique/
https://www.qualitymag.com/articles/93223-the-inside-story-on-industrial-ct-scanning
https://pubs.rsna.org/doi/10.1148/rg.246045065
THANK YOU
Members
Akriti Belbase
Manisha Upreti
Design and Manufacturing
(4 th Year, 1 st Sem)
Mechanical Engineering
Kathmandu University