Effects of Using an External Electromagnetic Force on Transport Phenomena and Weld Quality in Laser Welding

2012 ◽  
Author(s):  
Jun Zhou ◽  
Hai-Lung Tsai
Keyword(s):  
Laser Welding ◽  
Electromagnetic Force ◽  
Transport Phenomena ◽  
Weld Quality

Visual Evaluation of Cast Dental Alloys Welds Discontinuities in the Field of Fixed Prosthodontics

2011 ◽  
Vol 383-390 ◽  
pp. 4058-4064
Author(s):  
Sorin Porojan ◽  
Liliana Sandu ◽  
Florin Topală
Keyword(s):  
Laser Welding ◽  
Base Metal ◽  
Visual Inspection ◽  
Incomplete Fusion ◽  
Weld Quality ◽  
Dental Alloys ◽  
Visual Evaluation ◽  
Fixed Prosthodontics ◽  
Microplasma Welding

It is essential for a weld to satisfy the requirements of certain standards in the field where it is applied. The aim of the study was to highlight the discontinuities which can appear in the joints achieved by laser and microplasma welding of base metal dental alloys used in fixed prosthodontics. All types of discontinuities which are visible from visual inspection were searched: inclusions, inadequate joint penetration, incomplete fusion, undercuts, overlaps, underfills. Recognizing the defects and discontinuities and their delimitation was essential in determining the weld quality. The obtained results were satisfactory for the purpose both for microplasma and laser welding. Using these methods, welds without defects, which meet minimum acceptable standards for each case, could be obtained.

Zinc Transport Phenomena in Laser Welding of Coated Sheet Steel in Overlap Configuration

2008 ◽  
Vol 52 (7-8) ◽  
pp. 33-41
Author(s):  
R. R. G. M. Pieters ◽  
C. Goos ◽  
B. Rietman ◽  
I. M. Richardson
Keyword(s):  
Laser Welding ◽  
Transport Phenomena ◽  
Sheet Steel ◽  
Zinc Transport ◽  
Coated Sheet

Quality Assessment and Metallurgical Examination of Laser Welded Sheets

2009 ◽  
Vol 83-86 ◽  
pp. 611-615
Author(s):  
Numan Abu-Dheir ◽  
Bekir Sami Yilbas
Keyword(s):  
Laser Welding ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Careful Examination ◽  
Welding Parameters ◽  
Weld Quality ◽  
Laser Weld ◽  
Power Intensity ◽  
Segregation Profile

Laser welding of steel 316L sheets is considered and the effects of laser welding parameters on the laser weld quality and metallurgical changes in the weld section are presented. The laser weld quality is assessed through careful examination of weld geometrical features, and the resulting weld microstructure. Metallurgical changes in the weld sites are examined using optical, and electron scanning microscope (SEM). Two levels of heat inputs are used-1500W and 2000W; and two scanning speeds of 2cm/s and 4cm/s are used to laser weld 316L sheets. It is found that at the high laser power intensities, evaporation takes place in the irradiated region and as the laser power intensity increases further, a cavity is formed at the top surface of the welding cross section. A similar situation is also observed as the laser scanning speed reduces. The low diffusivity of the alloying elements at high temperatures preserves the segregation profile. The scattered partitioning of the cells and dendrite boundaries are observed due to the presence of Cr and Mo.

Effect of water depth on weld quality and welding process in underwater fiber laser welding

2017 ◽  
Vol 115 ◽  
pp. 112-120 ◽  
Author(s):  
Ning Guo ◽  
Xiao Xing ◽  
Hongyun Zhao ◽  
Caiwang Tan ◽  
Jicai Feng ◽  
...  
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
Water Depth ◽  
Welding Process ◽  
Weld Quality ◽  
Fiber Laser Welding ◽  
Effect Of Water

Effect of shielding conditions of local dry cavity on weld quality in underwater Nd:YAG laser welding

2006 ◽  
Vol 174 (1-3) ◽  
pp. 34-41 ◽  
Author(s):  
Xudong Zhang ◽  
Eiji Ashida ◽  
Susumu Shono ◽  
Fukuhisa Matsuda
Keyword(s):  
Laser Welding ◽  
Nd:Yag Laser ◽  
Weld Quality
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