Cathode Design of Aero-Engine Blades in Electrochemical Machining Based on Characteristics of Gap Distribution

2009 ◽  
Vol 69-70 ◽  
pp. 248-252 ◽  
Author(s):  
Ji Hua ◽  
Zhi Yong Li
Keyword(s):  
High Surface ◽  
Electrochemical Machining ◽  
Dimensional Accuracy ◽  
Machining Accuracy ◽  
Electrode Gap ◽  
Electrolyte Flow ◽  
High Surface Quality ◽  
Cathode Design ◽  
Aero Engine ◽  
Electric Filed

Cathode design is a difficult problem must be faced and solved in ECM. We develop a new numerical approach for cathode design by employing a finite element method and this approach has been applied in the cathode design of aero-engine blades in ECM. The mathematic models of the electric filed and electrolyte flow filed distribution in EMC process are described primarily. Then the realization procedure of this approach is presented，in which the effects of electric filed and electrolyte flow filed distribution within the inter-electrode gap domain are concentrated. In order to verify the machining accuracy of the designed cathodes, the experiments are conducted using an industrial scale electrochemical machining system. The experimental results demonstrate that the machined blade have high surface quality and dimensional accuracy which proves the proposed approach for cathode design of aero-engine blades in ECM is applicable and valuable.

The Effects of Normal Gap Distribution on Cathode Design of Aero-Engine Blades in Electrochemical Machining

2010 ◽  
Vol 97-101 ◽  
pp. 3583-3586 ◽  
Author(s):  
Zhi Yong Li ◽  
Hua Ji
Keyword(s):  
Design Method ◽  
Electrochemical Machining ◽  
Difficult Problem ◽  
Machining Process ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Three Dimension ◽  
Cathode Design ◽  
Aero Engine ◽  
Machining Rate

Cathode design is a difficult problem must be faced and solved in electrochemical machining (ECM). In ECM process, various parameters, such as applied voltage, current density, gap distribution, machining rate and electrolyte composition and concentration, can affect ECM machining process and therefore cathode design. Among all these machining parameters, gap distribution is the most vital. Regard some type of aero-engine compressor blade as research object, this paper concentrates on the effects of the normal gap distribution of 2-dimension and 3-dimension on cathode design based on the cathode design method of , moreover the errors between two and three dimension normal gap also can be compared and analyzed in detail. To verify the accuracy of the designed cathode, the machining experiments were conducted on an industrial scale ECM machine and the experimental results demonstrates that the cathode designed utilizing 3-dimension normal gap exhibits more machining accuracy and therefore valuable.

Improvement of leading-edge accuracy by optimizing the cathode design plane in electrochemical machining of a twisted blade

2019 ◽  
Vol 234 (4) ◽  
pp. 814-824 ◽  
Author(s):  
Lingguo Yu ◽  
Dong Zhu ◽  
Yujun Yang ◽  
Jibin Zhao
Keyword(s):  
Three Dimensional ◽  
Electrochemical Machining ◽  
Leading Edge ◽  
The Body ◽  
Machining Process ◽  
Machining Accuracy ◽  
Electrode Gap ◽  
Cathode Design ◽  
Twisted Blade ◽  
Blade Leading Edge

Cathode design plays an important role in the electrochemical machining of aero engine blades and is a core issue influencing machining accuracy. Precision electrochemical machining of the leading edge of a twisted blade is particularly difficult. To improve the electrochemical machining accuracy of the leading edge, this article deals with cathode design by optimizing the design plane based on the three-dimensional potential distribution in the inter-electrode gap. A mathematical model is established according to the electrochemical machining shaping law, and the formation of the blade leading edge is simulated using ANSYS. The simulation results show that the blade leading-edge profile obtained with the optimized planar cathode is more consistent with the blade model profile. The optimized planar cathode and a non-optimized planar cathode are designed and a series of corresponding electrochemical machining experiments is carried out. The experiments show that the electrochemical machining process is stable and that the surface quality near the leading edge of the samples is slightly better than that of the body surface. Compared with the non-optimized planar cathode, the allowance difference at the leading-edge vertex is decreased by 0.062 mm. Using the optimized planar cathode allows fabrication of a workpiece whose shape is similar to that of the designed twisted blade.

Benchmark test artifacts for selective laser melting – a critical review

2021 ◽  
Vol 15 ◽  
Author(s):  
Weishi Li ◽  
Kuanting Wang ◽  
Shiaofen Fang
Keyword(s):  
Selective Laser Melting ◽  
High Surface ◽  
Dimensional Accuracy ◽  
Melting Process ◽  
Design Guidelines ◽  
Laser Melting ◽  
Specific Test ◽  
Benchmark Test ◽  
High Surface Quality ◽  
Machine Performance

Background: Selective laser melting is the best-established additive manufacturing technology for high-quality metal part manufacturing. However, the widespread acceptance of the technology is still underachieved, especially in critical applications, due to the absence of a thorough understanding of the technology, although several benchmark test artifacts have been developed to characterize the performance of selective laser melting machines. Objective: The objective of this paper is to inspire new designs of benchmark test artifacts to understand the selective laser melting process better and promote the acceptance of the selective laser melting technology. Method: The existing benchmark test artifacts for selective laser melting are analyzed comparatively, and the design guidelines are discussed. Results: The modular approach should still be adopted in designing new benchmark test artifacts in the future, and task-specific test artifacts may also need to be considered further to validate the machine performance for critical applications. The inclusion of the design model in the manufactured artifact, instead of the conformance to the design specifications, should be evaluated after the artifact is measured for the applications requiring high-dimensional accuracy and high surface quality. Conclusion: The benchmark test artifact for selective laser melting is still under development, and a breakthrough of the measuring technology for internal and/or inaccessible features will be beneficial for understanding the technology.

scholarly journals Research on Stagger Coupling Mode of Pulse Duration and Tool Vibration in Electrochemical Machining

2018 ◽  
Vol 8 (8) ◽  
pp. 1296 ◽  
Author(s):  
Xiaochen Jiang ◽  
Jia Liu ◽  
Di Zhu ◽  
Mingming Wang ◽  
Ningsong Qu
Keyword(s):  
Pulse Duration ◽  
Feed Rate ◽  
Electrochemical Machining ◽  
Machining Accuracy ◽  
Electrode Gap ◽  
Tool Vibration ◽  
Coupling Mode ◽  
Machining Localization ◽  
Electrolysis Products ◽  
Gas Void Fraction

Tuning the coupling of pulse duration and tool vibration in electrochemical machining (PVECM) is an effective method to improve machining accuracy and surface quality. In general, the pulse is set at the same frequency as the tool vibration, and a symmetrical distribution is attained at the minimum inter-electrode gap. To analyse the characteristics of the electrolyte fluid flow and of the electrolysis products in the oscillating inter-electrode gap, a dynamic simulation of the PVECM process was carried out. The simulation results indicated that the electrolyte pressure and gas void fraction when the pulse arrived as the inter-electrode gap was narrowing clearly differed from those when the inter-electrode gap was expanding. Therefore, in addition to the traditional symmetry coupling mode, two other coupling modes called the pre-position and the post-position coupling modes are proposed which use a pulse either just before or just after the minimum inter-electrode gap. Comparative experiments involving the feed rate and machining localization were carried out to evaluate the influence of the three coupling modes. In addition, current waveforms were recorded to analyse the differences between the three coupling modes. The results revealed that the highest feed rate and the best machining localization were achieved by using the pre-position coupling mode.

Influence of Manufacturing Process on the Fatigue Strength of Gears

2014 ◽  
Vol 1018 ◽  
pp. 269-276
Author(s):  
Andrea Reiß ◽  
Ulf Engel
Keyword(s):  
Fatigue Strength ◽  
Surface Quality ◽  
Fatigue Behavior ◽  
High Surface ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Cold Forging ◽  
Hardness Distribution ◽  
Forming Process ◽  
High Surface Quality

With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between manufacturing parameters on the one side, strength and other properties like hardness distribution and surface quality of the component on the other side. The research work covered in this paper focuses on the correlation of the components properties influenced by its manufacturing history and their fatigue strength. The used component is a gear produced by a lateral cold forging process. For the investigations an experimental setup has been designed. The aim for the design of the setup is to reproduce the real contact condition for the contact of two gears. To obtain different component properties the production process of the gear was varied by producing the parts by a milling operation. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.

Comparative Analysis of Flow Field in Mixed and Non Mixed Gas Electrochemical Machining for Aero-Engine Turbine Blade Cooling Holes

2017 ◽  
Vol 868 ◽  
pp. 166-171
Author(s):  
Zhing Yong Li ◽  
Xiu Ting Wei ◽  
Wen Wen Lu ◽  
Qing Wei Cui
Keyword(s):  
Flow Field ◽  
Flow Velocity ◽  
Turbine Blade ◽  
Electrochemical Machining ◽  
Machining Accuracy ◽  
Mixed Gas ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Vortex Zone ◽  
Aero Engine

By the cooling holes in aero-engine turbine blade as the research object, this study focuses on two kinds of ECM methods, which are mix gas added to the nonlinear electrolyte (NaNO3) and non-mixed gas. Mixed and non-mixed gas ECM experiments of turbine blade cooling holes were carried out respectively. The corresponding two-dimensional CAD model of cooling hole was constructed combined with the experimental data and theoretical analysis. Numerical simulation analysis was carried out of the flow field base on the above models by using the fluid dynamics analysis software FLUENT. The influence flow velocity and flow velocity distribution on the machining accuracy and efficiency of ECM were investigated in detail. The vortex zone distribution of gas-NaNO3 mixed phase flow field and single NaNO3 solution flow field was analyzed qualitatively. The simulation results indicated that the flow velocity in the machining gap with mixed gas was significantly higher than the velocity during ECM process for cooling holes. The electrolytic products and heat were washed away completely, the electrolyte can be updated in time. Fluid vortex zone distribution was improved obviously, the flow field distribution became more uniform after mixed gas in ECM process. The machining accuracy and efficiency for cooling holes making may be improved greatly with gas mixed in electrolyte NaNO3.

Machining Parameter Optimization of Aero-Engine Blade in Electrochemical Machining Based on BP Neural Network

2010 ◽  
Vol 121-122 ◽  
pp. 893-899 ◽  
Author(s):  
Zhi Yong Li ◽  
Hua Ji ◽  
Hong Li Liu
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Electrochemical Machining ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Parameter Combination ◽  
Aero Engine ◽  
Engine Blade ◽  
Blade Machining ◽  
Machining Parameter

Because the process of blade in electrochemical machining(EMC) can be effected by many factors, such as blade shapes, machining electrical field, electrolyte fluid field and anode electrochemical dissolution, different ECM machining parameters maybe result in great affections on blade machining accuracy. Regard some type of aero-engine blade as research object, five main machining parameters, applied voltage, initial machining gap, cathode feed rate, electrolyte temperature and pressure difference between electrolyte inlet and outlet, have been evaluated and optimized based on BP neural network technique. From 3125 possible machining parameter combinations, 657 optimized parameter combinations are discovered. To verify the validity of the optimized ECM parameter combination, a serial of machining experiments have been conducted on an industrial scale ECM machine, and the experiment results demonstrates that the optimized ECM parameter combination not only can satisfy the manufacturing requirements of blade fully but has excellent ECM process stability.

Ultra-precision grinding of asymmetric curved surfaces by line contact with cup wheel

2012 ◽  
Vol 227 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Guang Feng ◽  
Fengwei Huo ◽  
Dongming Guo ◽  
Renke Kang ◽  
Zhuji Jin
Keyword(s):  
High Surface ◽  
Work Piece ◽  
Machining Accuracy ◽  
Curved Surfaces ◽  
Line Contact ◽  
Wheel Wear ◽  
Shape Accuracy ◽  
High Surface Quality ◽  
Novel Approach ◽  
Cup Wheel

The wheel wear is a crucial factor affecting the shape accuracy while grinding the asymmetric curved surface components. To decrease the effects of the wheel wear and improve the machining accuracy, a novel approach of grinding with large-size and fine-grained cup wheel was suggested. This method has many advantages: a full line contact of the cup wheel against the work-piece can be realized, the wheel shape can be well maintained, and the wheel wear is uniform and can be compensated just by feeding along its axis. Moreover, a mathematical model was developed to analyze the grinding motion and the grinding principle deviation. Two hydrodynamic seal rings with wavy surfaces used in reactor coolant pumps were taken as examples to verify the practicability. It is expected to be an efficient method to manufacture more complex asymmetric curved surfaces with high shape accuracy and high surface quality.

scholarly journals Multiscale Assessment of Nanoscale Manufacturing Process on the Freeform Copper Surface

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3135
Author(s):  
Yafei Xu ◽  
Handing Liu ◽  
Liuyang Zhang ◽  
Matthew Becton
Keyword(s):  
Cutting Force ◽  
Surface Quality ◽  
Large Scale ◽  
Cutting Tool ◽  
High Surface ◽  
Computational Cost ◽  
Copper Sample ◽  
Machining Accuracy ◽  
Machining Mechanism ◽  
High Surface Quality

The nanocutting has been paid great attention in ultra-precision machining and high sealing mechanical devices due to its nanometer level machining accuracy and surface quality. However, the conventional methods applicable to reproduce the cutting process numerically such as finite element (FE) and molecular dynamics (MD) are challenging to unveil the cutting machining mechanism of the nanocutting due to the limitation of the simulation scale and computational cost. Here a modified quasi-continuous method (QC) is employed to analyze the dynamic nanocutting behavior (below 10 nm) of the copper sample. After preliminary validation of the effectiveness via the wave propagation on the copper ribbon, we have assessed the effects of cutting tool parameters and back-engagement on the cutting force, stress distribution and surface metamorphic layer depth during the nanocutting process of the copper sample. The cutting force and depth of the surface metamorphic layer is susceptible to the back-engagement, and well tolerant to the cutting tool parameters such as the tool rank angle and tool rounded edge diameter. The results obtained by the QC method are comparable to those from the MD method, which indicate the effectiveness and applicability of the modified QC method in the nanocutting process. Overall, our work provides an applicable and efficient strategy to investigate the nanocutting machining mechanism of the large-scale workpiece and shed light on its applications in the super-precision and high surface quality devices.

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