Investigations of laser microwelding using low power fibre laser for thin 304 stainless steel sheets

2017 ◽  
Vol 7 (2/3/4) ◽  
pp. 151
Author(s):  
V.K. Haribhakta ◽  
Sujit S. Pardeshi ◽  
Shrikant B. Patil
Keyword(s):  
Stainless Steel ◽  
Low Power ◽  
304 Stainless Steel ◽  
Fibre Laser ◽  
Steel Sheets ◽  
Laser Microwelding

scholarly journals Analysis of Acoustic Emission (AE) Signals for Quality Monitoring of Laser Lap Microwelding

2021 ◽  
Vol 11 (15) ◽  
pp. 7045
Author(s):  
Ming-Chyuan Lu ◽  
Shean-Juinn Chiou ◽  
Bo-Si Kuo ◽  
Ming-Zong Chen
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Frequency Domain ◽  
Monitoring System ◽  
Welding Quality ◽  
Steel Sheets ◽  
Signal Features ◽  
Ae Signal ◽  
Laser Microwelding ◽  
Ae Signals

In this study, the correlation between welding quality and features of acoustic emission (AE) signals collected during laser microwelding of stainless-steel sheets was analyzed. The performance of selected AE features for detecting low joint bonding strength was tested using a developed monitoring system. To obtain the AE signal for analysis and develop the monitoring system, lap welding experiments were conducted on a laser microwelding platform with an attached AE sensor. A gap between the two layers of stainless-steel sheets was simulated using clamp force, a pressing bar, and a thin piece of paper. After the collection of raw signals from the AE sensor, the correlations of welding quality with the time and frequency domain features of the AE signals were analyzed by segmenting the signals into ten 1 ms intervals. After selection of appropriate AE signal features based on a scatter index, a hidden Markov model (HMM) classifier was employed to evaluate the performance of the selected features. Three AE signal features, namely the root mean square (RMS) of the AE signal, gradient of the first 1 ms of AE signals, and 300 kHz frequency feature, were closely related to the quality variation caused by the gap between the two layers of stainless-steel sheets. Classification accuracy of 100% was obtained using the HMM classifier with the gradient of the signal from the first 1 ms interval and with the combination of the 300 kHz frequency domain signal and the RMS of the signal from the first 1 ms interval.

TENSILE AND FRACTURE BEHAVIOUR OF VERY THIN 304 STAINLESS STEEL SHEET

2016 ◽  
Vol 78 (6-9) ◽  
Author(s):  
Ammar Adil Al-Bakri ◽  
Zainuddin Sajuri ◽  
Ahmad Kamal Ariffin ◽  
Mohammed Abdul Razzaq ◽  
Mohd Salehudin Fafmin
Keyword(s):  
Stainless Steel ◽  
Cross Section ◽  
Steel Sheet ◽  
Rectangular Cross Section ◽  
Fracture Morphology ◽  
304 Stainless Steel ◽  
Stainless Steel Sheet ◽  
Steel Sheets ◽  
Ductile Mode ◽  
Mode Formation

Specimen with rectangular cross-section usually used to measure the tensile properties of materials. However, the specimen size and thickness may affect the results. In this study, tensile and fracture behaviours of very thin 304 stainless steel sheet were investigated. The thickness of the stainless steel sheets investigated were 100 and 300 µm. Tensile samples were cut into dumbbell-shaped of rectangular cross-section with same width for both thickness according to ASTM E8. The results showed that 100 µm thin steel sheet exhibited higher tensile strength with no clear evidence of yielding as compared to 300 µm sheet. The fracture morphology images observed by scanning electron microscopy revealed that both specimens fracture in ductile mode. Formation of dimples on the fracture surface could be recognized easily in 300 µm sample at higher magnification as compared to 100 µm sample.

Effect of Grain Size on Micro Ball Punch Deformation of SUS 304 Stainless Steel

2012 ◽  
Vol 579 ◽  
pp. 445-452 ◽  
Author(s):  
Chao Cheng Chang ◽  
Li Yi Lin
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
304 Stainless Steel ◽  
Steel Sheets ◽  
High Production Rate ◽  
Micro Parts ◽  
Deformation Test ◽  
High Production ◽  
Different Diameters ◽  
Deformation Tests

Micro metal forming is widely interested due to its potential in manufacturing micro parts with low costs and high production rate as the demands of compact devices have been increasing in many fields. This study uses micro ball punch deformation tests to investigate the effect of grain size on the formability of SUS 304 stainless steel sheets. The study employed annealing treatments to change the grain size of the sheets. By using three punches in different diameters in associated with three dies having an inner diameter of 2 mm and different die radii, it was able to perform micro bulging tests and obtain the bulging depths which were used to assess the formability of the sheets. The study shows that the grain size does affect the depth of the deformed dome in the ball punch deformation test at the micro scale.

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