Microstructures and Properties of Fiber Laser Welded ACM522 Magnesium Alloy Joint

2009 ◽  
Vol 610-613 ◽  
pp. 911-914 ◽  
Author(s):  
Jun Liu ◽  
Jun Hui Dong ◽  
K. Shinozaki
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Fiber Laser ◽  
Laser Power ◽  
Weld Bead ◽  
Deep Penetration ◽  
Fiber Laser Welding ◽  
Bead Width ◽  
Welding Joints ◽  
Deep Penetration Welding

The microstructure, mechanical properties, hardness, rules and mechanism of various parameters on formation of weld bead of Mg alloy ACM522 using a fiber laser welding were investigated. The results showed that sound welds without major defects could be produced and the mechanical properties of welding joints were good. With the increase of laser power, the penetration depth and bead width of the weld bead all increased. The mechanism of welding transformed from the conduction welding mode to the deep penetration welding mode and the weld beads aspect ratio became higher with the increase of heat input. The microstructure of weld metal was significantly finer and the hardness of weld metal was higher than that of the base metal.

Detection of Seam Offset Based on Molten Pool Characteristics during High-Power Fiber Laser Welding

2012 ◽  
Vol 549 ◽  
pp. 1064-1068
Author(s):  
Jian Bin Liang ◽  
Xiang Dong Gao ◽  
De Yong You ◽  
Zhen Shi Li ◽  
Wei Ping Ruan
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Molten Pool ◽  
High Energy ◽  
High Energy Density ◽  
Deep Penetration ◽  
Characteristic Parameters ◽  
Fiber Laser Welding ◽  
Deep Penetration Welding

Laser welding includes the heat conduction welding and the deep penetration welding. Deep penetration welding can not only penetrate the material completely, but also can vaporize the material. An important phenomenon during deep penetration welding is that molten pool in the weldment will appear a keyhole. The formation of the keyhole leads to a deep penetration weld with a high aspect ratio and this is the most advantageous feature of welding by high-energy-density beams. Small focus wandering off weld seam may result in lack of penetration or unacceptable welds, and largely reduce heating efficiency. In a fiber laser butt-joint welding of Type 304 austenitic stainless steel plate with a high power 6kW continuous wave fiber laser, an infrared sensitive high-speed video camera was used to capture the dynamic images of the molten pools. The configurations of molten pools were analyzed through image processing techniques such as median filtering, partial Otsu threshold segmentation and Canny edge to obtain the edge of keyholes and molten pools. The circular degree and the area of keyholes and the width and average gray of molten pools were defined as characteristic parameters to reflect the seam offset between the laser beam and the weld center. By analyzing the change of characteristic parameters during welding process, it was found that these parameters were related to the seam offset. Welding experimental results and analysis of characteristic parameters confirmed that the seam offset could be monitored and distinguished by molten pools configuration during high-power fiber laser welding.

Analysis of Microstructure and Mechanical Properties of 2A97T3 Al-Li Alloy Fiber Laser Welding Joint

2015 ◽  
Vol 1095 ◽  
pp. 677-683 ◽  
Author(s):  
Zhen Yi ◽  
Li Chen ◽  
En Guang He ◽  
Ming Chang
Keyword(s):  
Mechanical Properties ◽  
Laser Welding ◽  
Fiber Laser ◽  
Base Metal ◽  
Columnar Dendrite ◽  
Fiber Laser Welding ◽  
Columnar Crystal ◽  
Welding Joint ◽  
Microstructure And Mechanical Properties ◽  
Welding Joints

2A97 Al-Li alloy with good comprehensive performance is a new type of Al-Li alloys in our country,in order to meet the ever-increased long-term requirements of aerospace,aviation and armament industries,microstructure and mechanical properties of 2A97Al-Li alloy fiber laser welding joint were analyzed in this paper.The results show that:2A97 Al-Li alloy laser welding joints from welding fusion line to the center of welding seam are non-dendritic equiaxed grain zone,columnar crystal zone,columnar dendrite zone,equiaxed dendrite zone.Precipitates θ,T2 and T1 are probably exited in FZ,hardness of the center of FZ is the lowest.Yield strength of welding joints are about 70% of base metal,tensile strength are approximately 63% of the base metal.

Development of ultra deep penetration welding with 10 kW fiber laser

2008 ◽  
Author(s):  
Xudong Zhang ◽  
Eiji Ashida ◽  
Seiji Katayama ◽  
Masami Mizutani
Keyword(s):  
Fiber Laser ◽  
Deep Penetration ◽  
Deep Penetration Welding

Fiber Laser Welding of Noncombustible Magnesium Alloy

2008 ◽  
Vol 580-582 ◽  
pp. 479-482 ◽  
Author(s):  
Yuji Sakai ◽  
Kazuhiro Nakata ◽  
Takuya Tsumura ◽  
Mitsuji Ueda ◽  
Tomoyuki Ueyama ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Magnesium Alloy ◽  
Laser Welding ◽  
Fiber Laser ◽  
Vickers Hardness ◽  
Laser Power ◽  
Welded Joint ◽  
Welding Process ◽  
Fiber Laser Welding ◽  
Laser Welding Process

Noncombustible magnesium alloy AMC602 (Mg-6mass%Al-2mass%Ca) extruded sheet of 2.0mm thickness was successfully welded using a fiber laser welding process at welding speed of 10m/min at 3kW laser power. Tensile strength of the welded joint was about 82 to 88% of that of the base metal. Vickers hardness, tensile strength and micro structural properties are also discussed.

scholarly journals Deep Penetration Welding of Thick Section Steels with 10 kW Fiber Laser

2009 ◽  
Vol 27 (2) ◽  
pp. 64s-68s ◽  
Author(s):  
Xudong Zhang ◽  
Eiji Ashida ◽  
Seiji Katayama ◽  
Masami Mizutani
Keyword(s):  
Fiber Laser ◽  
Deep Penetration ◽  
Thick Section ◽  
Deep Penetration Welding

Elucidation of Welding Stability Based on Keyhole Configuration during High-Power Fiber Laser Welding

2011 ◽  
Vol 314-316 ◽  
pp. 941-944 ◽  
Author(s):  
Xiang Dong Gao ◽  
Qian Wen ◽  
Seiji Katayama
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Continuous Wave ◽  
High Energy ◽  
High Energy Density ◽  
Deep Penetration ◽  
Characteristic Parameters ◽  
Fiber Laser Welding ◽  
Welding Stability

During deep penetration laser welding, a keyhole is formed in the molten pool due to the intense recoil pressure of evaporation. The formation of the keyhole leads to a deep penetration weld with a high aspect ratio and this is the most advantageous feature of welding by high-energy-density beams. The configuration and characteristics of a keyhole are related to the welding stability. In a fiber laser butt-joint welding of Type 304 austenitic stainless steel plate with a high power 10 kW continuous wave fiber laser, an infrared sensitive high-speed video camera was used to capture the dynamic images of the molten pools. The configurations of a keyhole were analyzed through image processing techniques such as median filtering, wiener filtering and gray level threshold segmentation to obtain the edge of a keyhole. The width and the area of a keyhole were defined as the keyhole characteristic parameters, and the deviation between the laser beam and weld center as a parameter reflecting the welding stability. By analyzing the change of the keyhole characteristic parameters during welding process, it was found that these parameters were related to the welding stability. Welding experimental results and analysis of the keyhole characteristic parameters confirmed that the welding stability could be monitored and distinguished by a keyhole configuration during high-power fiber laser welding.

Welding of Austenitic Stainless Steel AISI 304 by Fiber Laser

2017 ◽  
Vol 891 ◽  
pp. 190-194
Author(s):  
Katarína Bártová ◽  
Mária Dománková ◽  
Jozef Bárta
Keyword(s):  
Fiber Laser ◽  
Welding Speed ◽  
Focal Point ◽  
Weld Bead ◽  
Bead Width ◽  
Statistical Software ◽  
Aisi 304 ◽  
Depth Measurement ◽  
Point Position ◽  
The Difference

Paper deals with the welding of AISI 304 thin sheets with the thickness of 1 mm by fiber laser. Statistical software MiniTab was used for planning the experiment. The influence of laser power, welding speed and focal point position on width and depth of weld bead was examined. Output power, welding speed and focus point position were used as variable factors for DOE. Samples were prepared by standard metallography. Weld bead width and depth were evaluated. Statistical results were afterward verified by welding reference samples with material the thickness of 0.25 mm. The difference between real width of weld bead and predicted width obtained from statistical software was 8.26 %. In case of weld depth measurement, the difference was 23 %.

Covered Electrodes Temperature Variation During Wet Welding and Its Influence on Weld Metal Porosity

2005 ◽  
Author(s):  
Ezequiel C. P. Pessoa ◽  
Alexandre Q. Bracarense ◽  
Stephen Liu ◽  
Faustino Peres Guerrero ◽  
Eduardo M. Zica
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Tensile Tests ◽  
Mechanical Tests ◽  
Weld Bead ◽  
Electrode Temperature ◽  
Charpy Test ◽  
Underwater Wet Welding ◽  
Porosity Reduction ◽  
Covered Electrodes

The objective of this work was to evaluate the porosity variation along weld bead and its relation with weld metal mechanical properties and electrode heating during underwater wet welding. Three commercial covered electrodes were used to make bead-on-plate welds. V-groove welds were also made using two electrodes at 50 and 100 meters depth in three different steels. Electrode temperature and weld metal porosity measurements and mechanical tests were performed. The results of temperature measurements indicated that electrode temperature increases during underwater wet welding. Simultaneously, porosity reduces along the BOP and V-groove weld beads. Mechanical tests showed that the mechanical properties are better at the end of welds. Additionally, the load supported by side bend tests samples extracted from 50 meter welds were higher than that measured for the 100 meter welds. Tensile test results also showed similar trend. Charpy test did not reveal any relation between the absorbed energy and porosity reduction along weld bead. However presented the same trend of bend and tensile tests at 50 and 100 m depth.

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