Microstructural Characterization of the Laser Welding in a Nickel Based Superalloy

MRS Advances ◽  
2019 ◽  
Vol 4 (63) ◽  
pp. 3463-3473
Author(s):  
Mayra Jurado ◽  
Gerardo Altamirano ◽  
Jorge Leobardo Acevedo ◽  
Alvaro Aguirre
Keyword(s):  
Heat Treatment ◽  
Laser Welding ◽  
Turbine Blades ◽  
Base Material ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Heat Treatment Condition ◽  
Nickel Base Superalloy ◽  
Micro Laser Welding ◽  
Laser Welding Process

ABSTRACTIn this research it was experimentally analyzed the effect of the parameters of the Pulsed Micro Laser Welding Process Nd:YAG on the microstructural behavior of a nickel base superalloy (IN-738). For this purpose, different laser welding tests were performed on samples subjected to different heat treatment conditions obtained from the gas turbine blades. The influence of the power and the speed welding of the applied process and heat treatment condition on the weld geometry, microstructure and mechanical properties was determined. The microstructures of the obtained welds were characterized by scanning electron microscopy and Vickers hardness tests. In general, alternatives to homogenize and rejuvenate the microstructure of the base material are proposed in order to avoid the formation and propagation of cracks. The results are discussed mainly in terms of the present phases and decomposition of carbides, which considerably affect the weldability of the IN-738 superalloy. This study provides useful information for the subsequent restoration of the 2nd step turbine blades by using of the Laser Welding Process Nd:YAG.

Microstructure Characterization of AZ31B Mg Alloy Welds Processed by Nd:YAG Laser Welding

2017 ◽  
Vol 898 ◽  
pp. 1051-1055 ◽  
Author(s):  
Hong Tao Liu ◽  
Ruo Chao Wang ◽  
Qing Liu ◽  
Ji Xue Zhou ◽  
Yan Fei Chen ◽  
...  
Keyword(s):  
Laser Welding ◽  
Nd:Yag Laser ◽  
Energy Dispersive Spectrometer ◽  
Base Material ◽  
Welding Process ◽  
Microstructure Characterization ◽  
Columnar Grains ◽  
Equiaxed Grains ◽  
Laser Welding Process

The Nd:YAG laser welding process of AZ31B alloys was performed by using the six-axis robot in this work. The microstructure characterization of AZ31B auto-welded joints was studied by using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The laser welding process resulted in the formation of equiaxed grains in the center of the fusion zone (FZ) and columnar grains near the FZ boundary, meanwhile some eutectic β-Mg17Al12 particles were observed in the microstructure. No clear heat affected zone (HAZ) was observed in the welded AZ31B joint. Furthermore, some pores were observed in the base material (BM) and FZ.

Effects of pre- and post-weld heat treatment conditions on microstructures of cast nickel based superalloys GTD-111 in the laser welding process

2019 ◽  
Vol 61 (8) ◽  
pp. 713-718
Author(s):  
Juthamate Jaruratchataphun ◽  
Panyawat Wangyao ◽  
Tanaporn Rojhirunsakool ◽  
Gobboon Lothongkum
Keyword(s):  
Heat Treatment ◽  
Laser Welding ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Treatment Conditions ◽  
Laser Welding Process ◽  
Weld Heat

Segmentation of Molten Pool Infrared Images Using Morphology during High Power Disk Laser Welding

2012 ◽  
Vol 201-202 ◽  
pp. 91-94
Author(s):  
Yan Xi Zhang ◽  
Xiang Dong Gao
Keyword(s):  
Laser Welding ◽  
High Power ◽  
Molten Pool ◽  
Welding Process ◽  
Histogram Equalization ◽  
Welding Quality ◽  
Infrared Images ◽  
Traditional Methods ◽  
Disk Laser ◽  
Laser Welding Process

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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