properties of plasma welds
DESCRIPTION
Properties of Plasma Welds. Rafael Jaramillo Greg Angelides Linda McLaren. Overview. Experimental Objectives and Motivation Previous Work Experimental Design Results Future Work. Objectives and Motivation. Create a complete database of plasma welds - PowerPoint PPT PresentationTRANSCRIPT
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Properties of Plasma Welds
Rafael Jaramillo
Greg Angelides
Linda McLaren
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Overview• Experimental Objectives
and Motivation
• Previous Work
• Experimental Design
• Results
• Future Work
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Objectives and Motivation
• Create a complete database of plasma welds• Study how speed and amperage affect the weld attributes.
- width- depth- structure
• Determine whether temperatures read with a thermocouple correlate with Infrared Camera readings.
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Previous WorkTwo years ago an REU group created several plasma welds. Last year’s group organized them.
1.5 mm/s2.0 mm/s3.0 mm/s4.0 mm/s4.5 mm/s5.0 mm/s1.5 mm/s2.0 mm/s3.0 mm/s4.0 mm/s4.5 mm/s
60Amps 65 Amps 70 Amps 75 Amps
1.5mmps N/A
2.0mmps
2.5mmps
3.0mmps
3.5mmps N/A N/A N/A
4.0mmps N/A N/A N/A
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Experimental Setup
Fluke +Computer
Infrared Camera
Plasma Welding Robot
Sample Holder
Camera Control+ Television
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While Welding…
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Experimental Design Samples were cut and cleaned
Thermocouples were affixed
Sample was welded at specified
current and speed
Temperature Data was recorded using
a Fluke Hydra DAQ unit.
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Infrared Recordings were made during welding.
Cross sectional cut of samples
was made and put into molds
for microscope study.
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Polishing!
5 step polishing process
Fine polishing necessary for viewing microscopic structures
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Finding IR Camera Range Temp. range of IR camera had to
be set before welding process Tradeoff between visible
temperature range and temperature resolution
Range set at 200 – 700 oC Entire heating process could not
be captured
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Sample Weld Results
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Welding Temperature Plot
Sample 6
0
100
200
300
400
500
600
700
0 20 40 60 80
Time (s)
Tem
p
Upper Right
Lower Right
Lower Left
Upper Left
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IR vs. Thermocouple Temperature Readings
Sample 9, Upper Left
0
50
100
150
200
250
300
350
400
450
500
time
tem
p (
de
g. C
)
IR TemperatureData
ThermocoupleTemperature Data
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IR vs. Thermocouple Temperature Readings
Sample 9, Lower Left
0
100
200
300
400
500
600
700
800
900
time
tem
p (
de
g. C
)
IR Temp.
ThermocoupleTemp.
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IR vs. Thermocouple Temperature Readings
Sample 6, Lower Right
-100
0
100
200
300
400
500
600
700
800
0 10 20 30 40 50
time
tem
p (
de
g. C
)
IR Temperature
ThermocoupleTemperature
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Sources of Error
Unreliable thermocouples: ultrasonic welding process flattened the leads
IR data could not be taken at thermocouple’s exact location
IR camera pixel intensity found to be unreliable
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Thermocouple ProblemGood weld
Bad weld
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IR Pixel Intensity Problem
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Future Work
Examine samples under microscope for structural changes due to welding
Determine accurate method for measuring temperature
Compare to numerical model for welding process using MathCad