scholarly journals Fabrication of Taper Free Micro-Holes Utilizing a Combined Rotating Helical Electrode and Short Voltage Pulse by ECM

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 28 ◽  
Author(s):  
Yong Liu ◽  
Minghong Li ◽  
Jingran Niu ◽  
Shizhou Lu ◽  
Yong Jiang
Keyword(s):  
Voltage Pulse ◽  
High Speed ◽  
Manufacturing Industry ◽  
Difficult Problem ◽  
Machining Accuracy ◽  
Gap Flow ◽  
Electrochemical Drilling ◽  
Micro Holes ◽  
Micro Hole ◽  
Helical Electrode

Fabrication of the injection nozzle micro-hole on the aero engine is a difficult problem in today’s manufacturing industry. In addition to the size requirements, the nozzle micro-hole also requires no burr, no taper and no heat-affected zone. To solve the above problem, an ultra-short voltage pulse and a high-speed rotating helical electrode were used in electrochemical drilling (ECD) process. Firstly, a theoretical model of ECD with ultra-short voltage pulse was established to investigate the effects of many predominant parameters on machining accuracy, and the effect of rotating helical electrode on the gap flow field was analyzed. Secondly, sets of experiments were carried out to investigate the effects of many key parameters on machining accuracy and efficiency. Finally, the optimized parameters were applied to machine micro holes on 500 μm thickness of GH4169 plate, and micro-holes with the diameter of 186 μm with no taper were machined at the feed rate of 1.2 μm/s. It is proved that the proposed ECD process for fabricating micro-holes with no taper has a huge potential and broad application prospects.

Micro-Hole Machined by Electrochemical Discharge Machining (ECDM) with High Speed Rotating Cathode

2011 ◽  
Vol 295-297 ◽  
pp. 1794-1799 ◽  
Author(s):  
Shao Fu Huang ◽  
Di Zhu ◽  
Yong Bin Zeng ◽  
Wei Wang ◽  
Yong Liu
Keyword(s):  
High Speed ◽  
Electrochemical Machining ◽  
304 Stainless Steel ◽  
Machining Accuracy ◽  
Micro Machining ◽  
Rotating Speed ◽  
Electrochemical Discharge Machining ◽  
Electrochemical Discharge ◽  
Micro Holes ◽  
Micro Hole

Electrochemical discharge machining (ECDM), based on electrochemical machining (ECM) and electrodischarge machining (EDM), is an unconventional micro-machining technology. In this paper, with the use of water, the process of micro hole on ANSI 304 stainless steel machined by micro-ECDM with high speed rotating cathode is studied. The effects of machining conditions such as the cathode rotating speed and cathode diameter on the surface quality and accuracy of the shape are investigated. The results indicate that a relatively higher electrode rotating speed can improve the machining accuracy of the micro-holes and reduce the electrodes wear.

Experimental Study on Electrochemical Drilling of Micro Holes with High Aspect Ratio

2014 ◽  
Vol 941-944 ◽  
pp. 1952-1955 ◽  
Author(s):  
Yong Liu ◽  
Shao Fu Huang
Keyword(s):  
Aspect Ratio ◽  
High Speed ◽  
Electrochemical Machining ◽  
Difficult Problem ◽  
Drilling Process ◽  
Electrochemical Drilling ◽  
Drilling Technology ◽  
Micro Holes ◽  
Machining System ◽  
Rotary Speed

It is a difficult problem to fabricate deep and micro holes on the difficult-to-cut metals in the field of aviation manufacturing. The experimental research of electrochemical drilling technology with high-speed micro electrode for fabricating deep micro holes is carried out. The influences of rotary speed on machining precision and stability are studied. The holes, which the diameter is about 400μm, the aspect ratio is more than 10, and have steep wall and sharp edges were fabricated successfully on the nickelbase superalloys on self-developed high-precision micro-electrochemical machining system. It is proved that the high-speed electrochemical drilling process for fabricating deep and micro holes has a huge potential and broad application prospects.

Fabrication of Micro Structures by Ultra Short Voltage Pulse Electrochemical Machining

2009 ◽  
Vol 419-420 ◽  
pp. 813-816 ◽  
Author(s):  
Hui Chen ◽  
Zhen Long Wang ◽  
Zi Long Peng ◽  
Wan Sheng Zhao
Keyword(s):  
Voltage Pulse ◽  
Electrochemical Machining ◽  
Pulse Frequency ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Stray Current ◽  
Micro Fabrication ◽  
Micro Hole ◽  
Micro Structures ◽  
Machining Localization

. The purpose of this paper is to study the application of electrochemical machining (ECM) technology for the fabrication of micro structures. The stray current corrosion, i.e. machining localization is a critical obstacle to micro fabrication for ECM. To machine micro structures by electrochemical machining ultra short voltage pulse is used. The effects of electrochemical machining parameters such as voltage, pulse duration, pulse frequency, and electrolyte composition on the machining accuracy were studied. In experiments, a micro hole was machined on stainless steel with cylindrical and square electrodes to investigate these effects.

scholarly journals Investigation on the Electrochemical Micromachining of Micro Through-Hole by Using Micro Helical Electrode

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 118 ◽  
Author(s):  
Baohui Liu ◽  
Hang Zou ◽  
Haixuan Luo ◽  
Xiaoming Yue
Keyword(s):  
Process Parameters ◽  
High Speed ◽  
Pulse Frequency ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Good Effect ◽  
Machining Accuracy ◽  
High Speed Rotation ◽  
Helical Electrode ◽  
Through Hole

The instability of machining process caused by the difficulty of the electrolyte refresh in electrochemical micromachining (EMM) of micro through-hole has been an unsolved problem. Thus, this paper investigates the electrochemical micromachining of micro through-hole by using a micro helical electrode combining with the jetting electrolyte. With the help of high-speed rotation of micro helical electrode and its spiral shape, the internal electrolyte can be stirred while the external jetting electrolyte can flow into the hole along the spiral groove to refresh the electrolyte effectively, thereby, improving the machining stability of EMM. Firstly, the influence of the process parameters on the fabrication of micro through-hole in the EMM by using micro helical electrode without non-conductive mask is investigated. Based on the optimization of the process parameters, a micro through-hole with an inlet dimension of 121.6 μm and an outlet dimension of 114.9 μm is obtained successfully. Furthermore, this paper also tries to use the micro helical electrode coated with the non-conductive mask to decrease the bad influence of the stray corrosion attack. It is found that the non-conductive mask coated on the surface of micro helical electrode can improve the machining accuracy significantly under the condition of low pulse frequency (≤1 KHz). However, its good effect on preventing the stray corrosion decreases along with the increase of the pulse frequency.

Improvement of thread turning process using micro-hole textured solid-lubricant embedded tools

2021 ◽  
pp. 095440542110199
Author(s):  
Salman Khani ◽  
Seyedhamidreza Shahabi Haghighi ◽  
Mohammad Reza Razfar ◽  
Masoud Farahnakian
Keyword(s):  
Surface Roughness ◽  
Mechanical Strength ◽  
Solid Lubricant ◽  
Operating Cost ◽  
Contact Length ◽  
Solid Lubrication ◽  
Turning Process ◽  
Micro Holes ◽  
Micro Hole ◽  
Cutting Inserts

In this paper, the thread turning of aluminum 7075-T6 alloy is studied using micro-hole textured solid-lubricant embedded carbide inserts. The primary focus of this work is to enhance the performance of the thread turning process for producing high quality threaded parts. To achieve this, micro-holes were generated by laser micro-machining on the rake face of tools and then, MoS2 and CNT (carbon nanotube) solid-lubricants were embedded into micro-holes. The effects of micro-holes and solid-lubrication on the performance of the thread turning process were examined using traditional tool ( T0), micro-hole textured tool ( T1), micro-hole textured MoS2 embedded tool ( T2), and micro-hole textured CNT embedded tool ( T3). In this study, cutting forces, chip-tool contact length, built-up edge (BUE), surface roughness, and operating cost were investigated. The influence of micro-hole generation on the mechanical strength of cutting inserts was evaluated using the finite element method. The results showed that the fabrication of the micro-holes on the rake surface of cutting inserts has no significant effect on the mechanical strength of the tools. The comparisons of our method with traditional tools demonstrated that the cutting performance improved in the threading process. Our results reveal that the main cutting force, radial thrust force, surface roughness, built-up edge, and chip-tool contact length reduced 37.1%, 40.9%, 37.9%, 58.3%, and 38.2%, respectively, as T3 tools are applied in this process. A cost analysis, based on estimated tooling costs, showed that the T3 tool can yield an 18% reduction in overall operating cost.

scholarly journals Towards Efficient Milling of Multi-Cavity Aeronautical Structural Parts Considering ACO-Based Optimal Tool Feed Position and Path

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 88
Author(s):  
Yupeng Xin ◽  
Yuanheng Li ◽  
Wenhui Li ◽  
Gangfeng Wang
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Milling Process ◽  
Ant Colony ◽  
Machining Accuracy ◽  
Ant Colony Optimization Algorithm ◽  
Peripheral Milling ◽  
Structural Part ◽  
Milling Method ◽  
Structural Parts

Cavities are typical features in aeronautical structural parts and molds. For high-speed milling of multi-cavity parts, a reasonable processing sequence planning can significantly affect the machining accuracy and efficiency. This paper proposes an improved continuous peripheral milling method for multi-cavity based on ant colony optimization algorithm (ACO). Firstly, by analyzing the mathematical model of cavity corner milling process, the geometric center of the corner is selected as the initial tool feed position. Subsequently, the tool path is globally optimized through ant colony dissemination and pheromone perception for path solution of multi-cavity milling. With the advantages of ant colony parallel search and pheromone positive feedback, the searching efficiency of the global shortest processing path is effectively improved. Finally, the milling programming of an aeronautical structural part is taken as a sample to verify the effectiveness of the proposed methodology. Compared with zigzag milling and genetic algorithm (GA)-based peripheral milling modes in the computer aided manufacturing (CAM) software, the results show that the ACO-based methodology can shorten the milling time of a sample part by more than 13%.

scholarly journals Experimental study on machining deformation of large scale slender beam with weak stiffness  of Ti6Al4V

2021 ◽  
Author(s):  
Qimeng Liu ◽  
Jinkai Xu ◽  
Huadong Yu
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
High Speed ◽  
Large Scale ◽  
Machining Accuracy ◽  
Beam Structure ◽  
High Speed Milling ◽  
Deformation Problem ◽  
Machining Deformation ◽  
Slender Beams

Abstract Large-scale slender beam structures with weak stiffness are widely used in the aviation field. There will be a great deformation problem in machining because the overall stiffness of slender beam parts is lower. Firstly, the cutting mechanism and stability theory of the Ti6Al4V material are analyzed, and then the auxiliary support is carried out according to the machining characteristics of the slender beam structure. The feasibility of the deformation suppression measures for the slender beam is verified by experiments. The experimental analysis shows that on the basis of fulcrum auxiliary support, the filling of paraffin melt material is capable of increasing the damping of the whole system, improving the overall stiffness of the machining system, and inhibiting the chatter effect of machining. This method is effective to greatly improve the accuracy and efficiency during machining of slender beam parts. On the premise of the method of processing support with the combination of fulcrum and paraffin, if the tool wear is effectively controlled, the high precision machining of large-scale slender beams can be realized effectively, and the machining deformation of slender beams can be reduced. Although high speed milling has excellent machining effect on the machining accuracy of titanium alloy materials, severe tool wear is observed during high-speed milling of titanium alloy materials. Therefore, high-speed milling of titanium alloy slender beam is suitable to be carried out in the finishing process, which can effectively control tool wear and improve the machining accuracy of parts. Finally, the process verification of typical weak stiffness slender beam skeleton parts is carried out. Through the theoretical and technical support of the experimental scheme, the machining of large-scale slender beam structure parts with weak stiffness is realized.

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