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.

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.

Primary Research on Jet ECM Processing of Difficult to Cut Materials

2013 ◽  
Vol 554-557 ◽  
pp. 1793-1799 ◽  
Author(s):  
Piotr Lipiec ◽  
Dominik Wyszynski ◽  
Sebastian Skoczypiec
Keyword(s):  
Current Density ◽  
Large Scale ◽  
Electrochemical Machining ◽  
Current Density Distribution ◽  
Electrochemical Process ◽  
Experiment Planning ◽  
Work Piece ◽  
Machined Surface ◽  
Jet Electrochemical Machining ◽  
Electrolyte Jet

Unconventional production techniques became interesting and promising part of manufacturing methods. They provide complementary, to traditional loss methods, solutions enabling use of high - performance engineering materials for construction of machinery and industrial equipment. By using properly selected methods or their hybrids difficult to cut materials as steel, alloys, sintered materials and composites can be processed. Among the wide variety of unconventional methods of materials forming, particular attention should be given to electrochemical machining, which has been successfully used in various industries. This fact proves attractiveness and versatility of ECM. The method could be used on large scale and many variations was developed as each application requires an individual approach and has own requirements. One of the least known and described type of electrochemical machining is jet ECM where the electrolyte jet stream acts as a tool. In this kind of machining, the part is shaped only in the area where the electrolyte jet strikes the surface. This is due to the fact that the current density distribution is located just below the stream. In the area around the jet hitting the work piece thin electrolyte layer is formed. Thickness of that layer is growing rapidly. Since the electrolyte jet machining is an electrochemical process, the machined surface has all the benefits of ECM. There is no burrs and low temperature of the process prevents appearance of cracks and there is no heat-affected zone. Electrolyte jet machining can be used as well as in macro and micro drilling, turning, texturing, and electroplating. The process can be controlled by proper selection of such parameters as time, the current density and the diameter of the jet. Jet ECM can be used not only for material removal, but also for coloration (passivation) by means of anodic dissolution. 3D shaping of elements is also possible by controlling the current and the velocity of the electrolyte stream. In addition, by changing the polarity of the applied voltage it is possible to use this method in broadly considered electroplating. The paper presents results of the initial research on jet electrochemical machining (jet ECM) of acid proof steel and tungsten carbide. The material processing was carried in two ways – drilling holes and shaping grooves. Shaping was realized in milling and face turning regime. The influence of the two basic process parameters voltage and pressure was examined. In order to get rough information about the jet ECM process experiment planning method was applied. Obtained results enable planning of the further extended research.

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.

Process Energy Analysis for Aluminium Alloy and Stainless Steel in Laser-Assisted Jet Electrochemical Machining

2006 ◽  
Vol 220 (3) ◽  
pp. 405-412 ◽  
Author(s):  
P T Pajak ◽  
A K M De Silva ◽  
D K Harrison ◽  
J A McGeough
Keyword(s):  
Specific Energy ◽  
Metal Removal ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Material Surface ◽  
Power Laser ◽  
Electrochemical Current ◽  
Process Energy ◽  
Jet Electrochemical Machining ◽  
Electrolyte Jet

Laser-assisted jet electrochemical machining (LAJECM) is a hybrid process that combines a relatively low-power laser beam (typically 375 mW) with an electrolyte jet to facilitate metal removal. The main purpose of the laser is to enhance the localization effect of electrochemical dissolution from the workpiece, thus giving better precision and efficiency. The laser thermally activates the material surface where it impinges, thereby increasing the electrochemical current density in that localized zone. This paper reports recent investigations of LAJECM process energy distribution and explains the influence of laser assistance on dissolution removal rates using theoretical as well as experimental analysis. It was found that laser assistance increases energy in the LAJECM process by up to 45 per cent compared with jet electrochemical machining (JECM). The process energy has also been related to volumetric removal rate, and the specific energy required for machining with given variables has been calculated. It has been proved that LAJECM is more effective then JECM as the calculated specific energy was lower by up to 30 per cent.

Study of Electrochemical Jet Machining Process

1996 ◽  
Vol 118 (4) ◽  
pp. 490-498 ◽  
Author(s):  
J. Kozak ◽  
K. P. Rajurkar ◽  
R. Balkrishna
Keyword(s):  
Turbine Blades ◽  
Electrochemical Machining ◽  
Small Diameter ◽  
Machining Process ◽  
Workpiece Material ◽  
Precise Control ◽  
Machining Rate ◽  
Jet Electrochemical Machining ◽  
The Relationship ◽  
Electrolyte Jet

Jet Electrochemical Machining (ECJM) employs a jet of electrolyte for anodic dissolution of workpiece material. ECJM is extensively used for drilling small cooling holes in aircraft turbine blades and for producing maskless patterns for microelectronics parts. ECJM process drills small diameter holes and complex shape holes without the use of a profile electrode. One of the most significant problems facing ECJM user industries is the precise control of the process. A theoretical analysis of the process and a corresponding model are required for the development of an appropriate control system. This paper presents a mathematical model for determining the relationship between the machining rate and working conditions (electrolyte jet flow velocity, jet length, electrolyte properties, and voltage) of ECJM. This model describes a distribution of electric field and the effect of change of conductivity of electrolyte (caused by heating) on the process performance. A maximum dissolution rate is determined from the allowable increase of electrolyte temperature. Experimental verification of theoretical results is also presented.

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