Comparative Analysis of Vaporization Rates of 5456 Aluminum Alloying Elements during CO2 Laser Welding

2011 ◽  
Vol 478 ◽  
pp. 70-74
Author(s):  
Joseph I. Achebo ◽  
O. Oghoore

In this paper, the vaporization rates of Mg2+ and Al+ alloying elements of a 5456 aluminum plate were investigated using the CO2 laser welding process. The models proposed and used by Block-Bolten and Eagar in 1984 and Zhao and DebRoy in 2003 were applied with experimental results generated from this study. The vaporization rate of Mg2+ ions and Al+ ions using the equations proposed by Block-Bolten and Eagar gave 8.76 μgs-1cm-2 and 0.0465 μgs-1cm-2 respectively, whereas the equation proposed by Zhao and DebRoy gave 6.7 μgs-1cm-2 and 0.016 μgs-1cm-2 respectively. These values are within the reported values obtained by Block-Bolten and Eagar (1984). The heat transfer coefficient for Mg2+ and Al+ ions were also obtained. The vapor bubble radius including the surface tension and buoyancy forces were examined. The evaporative power and energy losses as a result of these bubbles’ collapse were calculated. The paper clearly shows the comparative analysis of alloying elements’ vaporization process in the aluminum metal heating process.

2007 ◽  
Vol 7-8 ◽  
pp. 133-138 ◽  
Author(s):  
E.M. Anawa ◽  
Abdul Ghani Olabi

Dissimilar metal welds between Ferritic steel and Austenitic steel (F/A)are commonly used in power plants, food industry, pharmaceutical industry and many other applications. There are many issues/problems associated with the joining of dissimilar materials, depending on the materials being joined and the process selected. During the laser welding process, residual stresses are introduced by a rise in temperature during the melting or heating process followed by a very quick cooling of the weld and the surrounding material. In this study, CO2 continuous laser welding has been successfully applied for joining 316 stainless steel with AISI 1009 low carbon steel F/A. Design of Experiment techniques (DOE) has been used for some of the selected welding parameters (laser power, welding speed, and focus position) to model the dissimilar F/A joints in terms of its residual stresses. The Hole-Drilling Method technique was use for measuring the residual stress of dissimilar welded components. Taguchi approach for selected welding parameters was applied and the output response was the residual stresses. The results were analysed using analysis of variance (ANOVA) and signal-tonoise (S/N) ratios for the effective parameters combination.


Author(s):  
Yan Zhang ◽  
DeShui Yu ◽  
JianPing Zhou ◽  
DaQian Sun ◽  
HongMei Li

Abstract To avoid the formation of Ti-Ni intermetallics in a joint, three laser welding processes for Ti alloy–NiTi alloy joints were introduced. Sample A was formed while a laser acted at the Ti alloy–NiTi alloy interface, and the joint fractured along the weld centre line immediately after welding without filler metal. Sample B was formed while the laser acted on a Cu interlayer. The average tensile strength of sample B was 216 MPa. Sample C was formed while the laser acted 1.2 mm on the Ti alloy side. The one-pass welding process involved the creation of a joint with one fusion weld and one diffusion weld separated by the remaining unmelted Ti alloy. The mechanical performance of sample C was determined by the diffusion weld formed at the Ti alloy–NiTi alloy interface with a tensile strength of 256 MPa.


2012 ◽  
Vol 201-202 ◽  
pp. 91-94
Author(s):  
Yan Xi Zhang ◽  
Xiang Dong Gao

Configuration of a molten pool is related to the laser welding quality. Analyzing the configuration of a molten pool is important to monitor the laser welding process. This paper proposes a method of segmentation of a molten pool and its shadow during high power disk laser welding, consequently provides the groundwork for reconstruction of the molten pool and analysis of welding quality. Subsection linear stretching histogram equalization was applied to enhance the contrast of the original images firstly, and then edge detection was used to highlight the edges. After that we used the morphology filtering method to produce the segmentation mask, and then combined the mask with the original images to get the final segmentation results. Also, the proposed method was compared with other traditional methods. The experimental results showed that our method not only could give better segmentation results and process large quantities images automatically, but also overcame the less-segmentation problems of traditional methods.


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