On-line detection method for porosity defects in high power fiber laser welding

2020 ◽  
Author(s):  
Xin Tang ◽  
Ping Zhong ◽  
Lingling Zhang ◽  
Jun Gu ◽  
Zhaopeng Liu ◽  
...  
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Detection Method ◽  
Line Detection ◽  
Fiber Laser Welding ◽  
Porosity Defects ◽  
On Line

Laser absorption in high-power fiber laser welding of stainless steel and aluminum alloy

2008 ◽  
Author(s):  
Naoyuki Matsumoto ◽  
Yousuke Kawahito ◽  
Masami Mizutani ◽  
Seiji Katayama
Keyword(s):  
Stainless Steel ◽  
Aluminum Alloy ◽  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Fiber Laser Welding ◽  
Laser Absorption

High-power fiber laser welding of thick steel at low welding speed

2007 ◽  
Author(s):  
Xudong Zhang ◽  
Eiji Ashida ◽  
Seiji Katayama ◽  
Masami Mizutani ◽  
Yusuke Anma ◽  
...  
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Welding Speed ◽  
Fiber Laser Welding ◽  
Thick Steel

Dynamic keyhole behavior and keyhole instability in high power fiber laser welding of stainless steel

2019 ◽  
Vol 114 ◽  
pp. 1-9 ◽  
Author(s):  
Dabin Zhang ◽  
Meng Wang ◽  
Chengsong Shu ◽  
Yunfei Zhang ◽  
Dongsheng Wu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Fiber Laser Welding ◽  
Keyhole Behavior

scholarly journals Effect of Heat Input on Porosity Defects in a Fiber Laser Welded Socket-Joint Made of Powder Metallurgy Molybdenum Alloy

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1433 ◽  
Author(s):  
Miao-Xia Xie ◽  
Yan-Xin Li ◽  
Xiang-Tao Shang ◽  
Xue-Wu Wang ◽  
Jun-Yu Pei
Keyword(s):  
Computed Tomography ◽  
Powder Metallurgy ◽  
Laser Welding ◽  
Fiber Laser ◽  
Heat Input ◽  
Dominant Role ◽  
Fusion Welding ◽  
Fiber Laser Welding ◽  
Welding Heat Input ◽  
Porosity Defects

Porosity defects are still a challenging issue in the fusion welding of molybdenum and its alloys due to the pre-existing interior defects associated with the powder metallurgy process. Fiber laser welding of end plug and cladding tube made of nanostructured high-strength molybdenum (NS-Mo) alloy was performed in this work with an emphasis on the role of welding heat input. The distribution and morphology of porosity defects in the welded joints were examined by computed tomography (CT) and scanning electron microscopy (SEM). Preliminary results showed that laser welding of NS-Mo under low heat input significantly reduced the porosity defects in the fusion zone. The results of computed tomography (CT) showed that when the welding heat input decreased from 3600 J/cm (i.e., 1200 W, 0.2 m/min) to 250 J/cm (i.e., 2500 W, 6 m/min), the porosity ratio of the NS-Mo joints declined from 10.7% to 2.1%. Notable porosity defects under high heat input were related to the instability of the keyhole, expansion and the merging of bubbles in the molten pool, among which the instability of the keyhole played the dominant role. The porous defects at low heat input were generated as bubbles released from the powder metallurgy base metal (BM) did not have enough time to overflow and escape.

Observation of spatter formation mechanisms in high-power fiber laser welding of thick plate

2013 ◽  
Vol 280 ◽  
pp. 868-875 ◽  
Author(s):  
M.J. Zhang ◽  
G.Y. Chen ◽  
Y. Zhou ◽  
S.C. Li ◽  
H. Deng
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Thick Plate ◽  
Formation Mechanisms ◽  
Fiber Laser 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.

scholarly journals Effects of Laser-Induced Plume in High-Power Fiber Laser Welding with Long-Focal-Distance Focusing Optics

2011 ◽  
Vol 29 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Yousuke KAWAHITO ◽  
Shinpei OIWA ◽  
Masami MIZUTANI ◽  
Seiji KATAYAMA
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Fiber Laser Welding ◽  
Focal Distance

Effect of plume on weld penetration during high-power fiber laser welding

2016 ◽  
Vol 28 (2) ◽  
pp. 022003 ◽  
Author(s):  
Jianglin Zou ◽  
Wuxiong Yang ◽  
Shikai Wu ◽  
Yue He ◽  
Rongshi Xiao
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Weld Penetration ◽  
Fiber Laser Welding

Control of the plume induced during high-power fiber laser welding with a transverse arc

2015 ◽  
Vol 12 (4) ◽  
pp. 046006 ◽  
Author(s):  
Shikai Wu ◽  
Jianglin Zou ◽  
Rongshi Xiao ◽  
Fei Li
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Fiber Laser Welding
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