Green Laser Drilling Assisted with Jet Electrochemical Machining of Nickel-Based Superalloy

2010 ◽  
Vol 426-427 ◽  
pp. 75-80 ◽  
Author(s):  
H. Zhang ◽  
Jia Wen Xu ◽  
J.M. Wang
Keyword(s):  
Electrochemical Machining ◽  
Frequency Doubling ◽  
Optical Microscope ◽  
Green Laser ◽  
Laser Drilling ◽  
Recast Layer ◽  
Ambient Atmosphere ◽  
Nickel Based Superalloy ◽  
Experimental Apparatus ◽  
Jet Electrochemical Machining

Laser drilling is extensively used in the aerospace and aircraft industries. The most important application is the drilling of fine cooling holes in aero turbine engine components such as nozzle guide vanes and blades. However, laser-drilled holes are typically associated with a number of inherent defects such as recast layer and spatter. In order to solve these problems, a novel hybrid process of laser drilling assisted with jet electrochemical machining (JECM-LD) has been developed to improve the overall quality of laser-drilled holes. The process based on the application of a jet electrolyte, being aligned coaxially with the focused laser beam, on the workpiece surface. The effects of the jet electrolyte during the process mostly consist of electro chemical reaction, effective cooling with materials and transporting debris. A pulsed Nd:YAG laser with frequency doubling is used in the JECM-LD experiments. On the basis of a measurement of laser attenuation in electrolyte, an experimental apparatus system is built and JECM-LD experiments are performed on 0.5mm thickness nickel-based superalloy sheets with the system. The optical microscope is used to detect the experimental results. It is found that the recast layer and spatter have been effectively removed during the JECM-LD compared with laser drilling in ambient atmosphere conditions. The efficiency of JECM-LD with millisecond green laser is about 70% of laser drilling in air.

Green Laser Drilling Assisted with Neutral Salt Solution

2010 ◽  
Vol 26-28 ◽  
pp. 698-701
Author(s):  
Hua Zhang ◽  
Jia Wen Xu ◽  
Jian She Zhao ◽  
Guo Ran Hua
Keyword(s):  
Salt Solution ◽  
Second Harmonic ◽  
Optical Microscope ◽  
Green Laser ◽  
Laser Drilling ◽  
Recast Layer ◽  
Ambient Atmosphere ◽  
Neutral Salt ◽  
New Processing

Recast layer is an inherent defect commonly associated with holes produced with laser drilling. The defect is likely to limit the extent of aero industrial application. In order to solve the problem, a new processing of laser drilling assisted with neutral salt solution (SALD) has been developed to improve the overall quality of laser-drilled holes. The process bases on the application of a fluid neutral salt solution, which is being on the workpiece surface with the focused laser beam at the same time. The effects of the neutral salt solution during the process mostly consist of thermal chemical reaction and continuing cooling effect of materials. Because of green laser being weakly absorbed underwater, the experiments of SALD have been performed on 0.5mm thickness 321 stainless steel with pulsed Nd:YAG laser at second harmonic wavelength. The optical microscope is used to detect the experimental results. It is found that the recast layer has been effectively removed during the SALD compared with laser drilling in ambient atmosphere conditions. It is confirmed that the principle of SALD is right and the new process can obtain good hole quality without recast layer.

Research on Hybrid Process of Laser Drilling With Jet Electrochemical Machining

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Lixin Yuan ◽  
Jiawen Xu ◽  
Jianshe Zhao ◽  
Hua Zhang
Keyword(s):  
Electrochemical Machining ◽  
Laser Drilling ◽  
Electrochemical Process ◽  
Recast Layer ◽  
Hybrid Process ◽  
Electrochemical Dissolution ◽  
Proper Distance ◽  
Metallurgical Defects ◽  
Jet Electrochemical Machining ◽  
Electrolyte Jet

The spatter and recast layer are main metallurgical defects in laser drilling (LD). Combining jet electrochemical process with laser can minimize such defects. The hybrid process is called electrolysis jet guided laser drilling (EJGLD). The presented experiment results show that the electrolyte jet can guide and transmit laser to the workpiece for drilling; and the electrochemical dissolution can effectively reduce spatter and recast layer. This paper introduces work on how to optimize this hybrid process, in particular, how to set a proper distance between the cathode and workpiece for best efficiency and accuracy.

Experimental Investigation on the Process of Jet Electrochemical Machining and Guided Laser Beam Machining

2010 ◽  
Vol 458 ◽  
pp. 325-330
Author(s):  
Li Xin Yuan ◽  
Jia Wen Xu ◽  
Jian She Zhao
Keyword(s):  
Laser Beam ◽  
Electrochemical Machining ◽  
Engineering Application ◽  
Recast Layer ◽  
Experimental Results ◽  
Laser Beam Machining ◽  
Metallurgical Defects ◽  
Jet Electrochemical Machining ◽  
Better Than

Laser beam machining is often associated with the metallurgical defects related with spatter, recast layer and heat-affected zone. In order to overcome the defects, this paper presents a process of jet electrochemical machining and guided laser beam machining (JECM-GLBM). On the explain of experimental principle and apparatus, jet electrochemical machining and laser beam machining(JECM-LBM) and JECM-GLBM experiments have been performed on 0.5mm thick 321S20 stainless steel under the same experimental condition respectively. The experimental results show that the entry circularity, repeatability and the surface quality of JECM-GLBM are significantly better than JECM-LBM, and the spatter and the recast layer of hole-wall has been mostly removed in JECM-GLBM. In addition, increasing the IEG leads that the taper and overcut are decreased in JECM-GLBM. By analyzing the experimental results, the best IEG is 10mm, which is unusually beneficial for the design of equipment in engineering application.

scholarly journals High-Efficiency Intracavity Continuous-Wave Green-Light Generation by Quasiphase Matching in a Bulk Periodically Poled MgO:LiNbO3 Crystal

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Shaowei Chu ◽  
Ying Zhang ◽  
Bin Wang ◽  
Yong Bi
Keyword(s):  
High Efficiency ◽  
Continuous Wave ◽  
Green Light ◽  
Frequency Doubling ◽  
Green Laser ◽  
Periodically Poled ◽  
Output Stability ◽  
532 Nm ◽  
Better Than ◽  
Quasiphase Matching

908 mW of green light at 532 nm were generated by intracavity quasiphase matching in a bulk periodically poled MgO:LiNbO3 (PPMgLN) crystal. A maximum optical-to-optical conversion efficiency of 33.5% was obtained from a 0.5 mm thick, 10 mm long, and 5 mol% MgO:LiNbO3 crystal with an end-pump power of 2.7 W at 808 nm. The temperature bandwidth between the intracavity and single-pass frequency doubling was found to be different for the PPMgLN. Reliability and stability of the green laser were evaluated. It was found that for continuous operation of 100 hours, the output stability was better than 97.5% and no optical damage was observed.

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