Optimization of new semi-automatic TIG welding process for surface quality through taguchi method
Tungsten inert gas (TIG) welding which uses a non-consumable tungsten electrode and an inert gas for arc shielding, is an extremely important arc welding process. The aims of this research project are to find optimization parameters in weld bead using TIG. Semi-automatic TIG was developed to ensu...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2014
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/1548/1/24p%20MOHD%20KHAIRULAMZARI%20HAMJAH.pdf http://eprints.uthm.edu.my/1548/2/MOHD%20KHAIRULAMZARI%20HAMJAH%20WATERMARK.pdf |
| Summary: | Tungsten inert gas (TIG) welding which uses a non-consumable tungsten
electrode and an inert gas for arc shielding, is an extremely important arc welding
process. The aims of this research project are to find optimization parameters in weld
bead using TIG. Semi-automatic TIG was developed to ensure the success of this
research project. Samples are produce in single bead and padding bead on top of
substrate (base metal) in horizontal position. Substrate material is from Mild Steel
AISI 1018 while wire filler ER70S-6 has a diameter of 0.8 mm and Tungsten
electrode EWth-2 (2% Thorium, Red) has a diameter 2.4mm. Argon is used as
shielding gas for this research project. Parameters such as Ampere (A), Travel Speed
(mm/s) and Wire Feed Rate (mm/min) has been determined and selected as factors
that can influence the weld bead result. Taguchi orthogonal array L9 (Minitab 16)
was used to determine the amount of runoff and the analysis of samples. The result
for surface roughness was found to be better with an average value of Ra 2.96 µm for
single bead and Ra 3.08 µm for padding bead when compared to the work of other
researchers. Surface hardness has also shown improvement from this research
project. Analysis result shows that the travel speed of the torch has the greatest effect
on surface roughness followed by wire feed rate and ampere. Dye Penetrant
Inspection (DPI) interpretations of the nearest Optimize level shows no cracks or
porosity occurring on top of the bead surface. Defects only happen at the undercut
weld due to improper start-up of the welding. For future study other parameters and
optimization technics need to be considered. The parameter combination must reflect
safety, environment issue and reasonable factors. |
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