scholarly journals Computer Simulation of High-Speed Anodic Dissolution Processes of Geometrically-Complex Surfaces of GTE Details

2014 ◽  
Vol 8 (1) ◽  
pp. 436-440 ◽  
Author(s):  
Maxim V. Nekhoroshev ◽  
Nikolay D. Pronichev ◽  
Gennadiy V. Smirnov
Keyword(s):  
Electric Fields ◽  
High Speed ◽  
Rapid Development ◽  
Electrochemical Machining ◽  
Aircraft Engine ◽  
Electrode Spacing ◽  
Work Piece ◽  
Tool Electrode ◽  
Electrode Gap ◽  
Switched Mode Power Supply

Electrochemical machining (ECM) is widely used in modern aircraft engine technology. This method was developed on a step-by-step basis in accordance with development of gas turbine equipment. Introduction of new difficult to machine materials into engines designs and improvement of accuracy of detail geometric parameters required new technological solutions. ECM method has a number of advantages: zero tool wear, the process does not depend on physical-mechanical properties of work piece material, no heat and force action on a work piece; these facts provide high quality of the surface layer and increase engine life. However, electrochemical machining has also disadvantages which essentially limit its applicability. This is primarily a low localization of ECM process. In order to eliminate this disadvantage new ECM schemes were developed, inter-electrode gap was reduced, switched mode power supply units, vibration of electrochemical machining electrode, etc. were used. Electrochemical machines design became more complicated and ECM operations design techniques required new solutions, therefore the scientific inquiry in this area continued intensively. Rapid development of computer technology contributed to the creation of digital models that adequately describe processes in the inter-electrode spacing at ECM. It is necessary to create electronic databases for various electrochemical metal-electrolyte systems, to develop techniques to simulate electric fields in the inter-electrode spacing, and to profile tool electrode automatically. The authors carried out active researches in this area at all stages of ECM development; they have a large number of publications in the field, including 4 monographs.

Research on Micro Electrochemical Machining Based on Multifunction Machine Tool

2009 ◽  
Vol 628-629 ◽  
pp. 399-404
Author(s):  
Xiao Hai Li ◽  
Li Jie Zhao ◽  
Xin Rong Wang ◽  
X. Zhang ◽  
Zhen Long Wang
Keyword(s):  
Stainless Steel ◽  
High Speed ◽  
Short Pulse ◽  
Electrochemical Machining ◽  
304 Stainless Steel ◽  
Tool Electrode ◽  
Electrode Gap ◽  
Micro Ecm ◽  
Gap Control ◽  
Ultra Short Pulse

The research aims to develop an experimental equipment to carry out in depth research on micro electrochemical machining (micro-ECM). The mechanisms of ultra-short pulse current micro ECM are discussed. As a consequence, lower machining voltage, lower passivity electrolyte concentration, high frequency short pulse power supply and micro rotating tool electrode at high speed have been synthetically used to localize the dissolution area during micro-ECM. The machining gap can be kept at a very small value, and the better resolution of machined shape is achieved by using a novel designed electrode gap control system and the effective utilization of ECM for micromachining is fulfilled. The experiments on microstructure by micro-ECM milling on stainless steel plate are conducted. The micro structures milled on 304 stainless steel foil with 300μm thickness with high precision and high aspect ratio are achieved, and the width of micro beam is about 60μm.

Removal of Defective Layer after Electrical Discharge Machining

2019 ◽  
Vol 973 ◽  
pp. 157-160
Author(s):  
Stanislav A. Mozgov ◽  
Yuriy A. Morgunov ◽  
Boris P. Saushkin
Keyword(s):  
Electrical Discharge ◽  
Metal Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Work Piece ◽  
Machining Parameters ◽  
Electrode Gap ◽  
Machining Time ◽  
Defective Layer

This study investigates the possibility of electrochemical removal of the defective layer formed on the surface of the product after its electrical discharge machining. A set of experiments was conducted in different electrolytes based on aqueous and aqueous-organic solvents. The experiments were to trace the influence of such settings of electrochemical machining as current density, electrolyte pumping speed, electrolyte temperature, and an electrode gap upon both the dynamics of metal removal and surface quality. Morphology of the obtained surface was examined by an Olympus BX-51Microscope. The dynamics of removing material (stock) from the work piece was inspected. Appropriate adjustments were made to the machining parameters during the machining of 65G steels, and a preferred composition was selected for the working medium. A sufficient design for production tools was proposed. Pitting corrosion was discovered on the surface of the samples in all studied modes of electrolysis. It was observed that switching from aqueous electrolyte to aqueous-organic electrolyte gave lower material removal rate and longer machining time accordingly. At the same time, a reduction in surface roughness was visualized, together with smaller pits and lower density of their distribution. The obtained results may be applied in operation design for electrochemical machining of steels with relatively high carbon contents.

Pulsed Micro-Electrochemical Machining Technology

2007 ◽  
Vol 339 ◽  
pp. 327-331 ◽  
Author(s):  
Xiao Hai Li ◽  
Zhen Long Wang ◽  
W.S. Zhao ◽  
Fu Qiang Hu
Keyword(s):  
Stainless Steel ◽  
High Speed ◽  
Short Pulse ◽  
Research Work ◽  
Electrochemical Machining ◽  
Tool Electrode ◽  
Stainless Steel Foil ◽  
Micro Ecm ◽  
Micro Hole ◽  
Micro Tool

This research work aims to explore the feasibility of applying electrochemical machining (ECM) to micromachining. An experimental setup for micro-ECM has been developed. Lower machining voltage, lower concentration of passivity electrolyte, high-frequency short-pulse power supply and micro tool electrode rotating at high speed have been synthetically adopted to localize the dissolution area in micro-ECM, so the machining gap can be kept at about 10 μm and the better resolution of machined shape is achieved. A micro-hole with 45μm diameter is drilled on the stainless steel foil with 100μm thickness. A new approach of fabricating microstructure by micro-ECM milling with a simple micro electrode is proposed, and the micro beam with width of about 50μm which has high precision is fabricated by micro-EC milling on the stainless steel foil (1Cr18Ni9Ti) with 300μm thickness. A mathematics model has been established, which can be used to simulate the process of shaping workpieces in the process of micro-ECM.

Recent Patents on the Angular Contact Ball Bearing of High-Speed Motorized Spindle

2020 ◽  
Vol 13 ◽  
Author(s):  
Yudong Bao ◽  
Linkai Wu ◽  
Yanling Zhao ◽  
Chengyi Pan
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Rapid Development ◽  
Ceramic Materials ◽  
Development Trend ◽  
Numerical Control ◽  
Angular Contact Ball Bearing ◽  
Practical Applications ◽  
High Speed Cutting ◽  
Advantages And Disadvantages

Background:: Angular contact ball bearings are the most popular bearing type used in the high speed spindle for machining centers, The performance of the bearing directly affects the machining efficiency of the machine tool, Obtaining a higher value is the direction of its research and development. Objective:: By analyzing the research achievements and patents of electric spindle angular contact bearings, summarizing the development trend provides a reference for the development of electric spindle bearings. Methods:: Through the analysis of the relevant technology of the electric spindle angular contact ball bearing, the advantages and disadvantages of the angular contact ball bearing are introduced, and the research results are combined with the patent analysis. Results:: With the rapid development of high-speed cutting and numerical control technology and the needs of practical applications, the spindle requires higher and higher speeds for bearings. In order to meet the requirements of use, it is necessary to improve the bearing performance by optimizing the structure size and improving the lubrication conditions. Meanwhile, reasonable processing and assembly methods will also have a beneficial effect on bearing performance. Conclusion:: With the continuous deepening of bearing technology research and the use of new structures and ceramic materials has made the bearing's limit speed repeatedly reach new highs. The future development trend of high-speed bearings for electric spindles is environmental protection, intelligence, high speed, high precision and long life.

Dynamic Performance of High-Speed Electric Multiple Unit within Multi-Body System Simulation

2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Body System ◽  
High Speed Railway ◽  
Evaluation Indexes ◽  
Actual Operation ◽  
Multiple Unit ◽  
The Stability ◽  
Multi Body

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.

scholarly journals Enhanced electrical conductivity and mechanical properties in thermally stable fine-grained copper wire

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Qingzhong Mao ◽  
Yusheng Zhang ◽  
Yazhou Guo ◽  
Yonghao Zhao
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Electrical Conductivity ◽  
Yield Strength ◽  
High Speed ◽  
Copper Wire ◽  
Rapid Development ◽  
Dislocation Slip ◽  
Ultrafine Grains ◽  
The Wire

AbstractThe rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.

The Design and Implementation of ECC High-Speed Encryption Engine Based on FPGA

2012 ◽  
Vol 459 ◽  
pp. 544-548 ◽  
Author(s):  
Wei Liang ◽  
Jian Bo Xu ◽  
Wei Hong Huang ◽  
Li Peng
Keyword(s):  
Data Transmission ◽  
High Speed ◽  
Lower Cost ◽  
Low Cost ◽  
Rapid Development ◽  
Security Technology ◽  
Multiplication Algorithm ◽  
Secure Data Transmission ◽  
And Performance ◽  
Computation Speed

Network security technology ensures secure data transmission in network. Meanwhile, it brings extra overhead of security system in terms of cost and performance, which seriously affects the rapid development of existing high-speed encryption systems. The existing encryption technology cannot meet the demand of high security, low cost and high real-time. For solving above problems, an ECC encryption engine architecture based on scalable public key cipher and a high-speed configurable multiplication algorithm are designed. The algorithm was tested on FPGA platform and the experiment results show that the system has better computation speed and lower cost overhead. By comparing with other systems, our system has benefits in terms of hardware overhead and encryption time ratio

scholarly journals Broadband Wireless Channel in Composite High-Speed Railway Scenario: Measurements, Simulation, and Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jianwen Ding ◽  
Lei Zhang ◽  
Jingya Yang ◽  
Bin Sun ◽  
Jiying Huang
Keyword(s):  
Ray Tracing ◽  
Communication Systems ◽  
High Speed ◽  
Channel Model ◽  
High Reliability ◽  
Rapid Development ◽  
Path Loss ◽  
Wireless Channel ◽  
Delay Spread ◽  
High Speed Railway

The rapid development of high-speed railway (HSR) and train-ground communications with high reliability, safety, and capacity promotes the evolution of railway dedicated mobile communication systems from Global System for Mobile Communications-Railway (GSM-R) to Long Term Evolution-Railway (LTE-R). The main challenges for LTE-R network planning are the rapidly time-varying channel and high mobility, because HSR lines consist of a variety of complex terrains, especially the composite scenarios where tunnels, cuttings, and viaducts are connected together within a short distance. Existing researches mainly focus on the path loss and delay spread for the individual HSR scenarios. In this paper, the broadband measurements are performed using a channel sounder at 950 MHz and 2150 MHz in a typical HSR composite scenario. Based on the measurements, the pivotal characteristics are analyzed for path loss exponent, power delay profile, and tap delay line model. Then, the deterministic channel model in which the 3D ray-tracing algorithm is applied in the composite scenario is presented and validated by the measurement data. Based on the ray-tracing simulations, statistical analysis of channel characteristics in delay and Doppler domain is carried out for the HSR composite scenario. The research results can be useful for radio interface design and optimization of LTE-R system.

The Analysis and Design of the Dynamic Information Service System Network Architecture of the SOA Based on WAVE Technology

2014 ◽  
Vol 1044-1045 ◽  
pp. 1380-1383
Author(s):  
Guang Li Yin
Keyword(s):  
Network Architecture ◽  
High Speed ◽  
Service System ◽  
Road Traffic ◽  
Rapid Development ◽  
Information Service ◽  
Advanced Technology ◽  
Living Standard ◽  
Vehicle Speed ◽  
Analysis And Design

Safety problem is one of the most attention and concern of driving. This paper in the high-speed on the road cars and car, car and road communications, vehicle real-time status, through the network information service system integration on a platform, on the use of related technologies are analyzed, the design of the software system based on SOA architecture.Keywords: network, GPS module, SOA cross platformI. IntorductionWith the development of science and technology and the improvement of people's living standard, Car popularity rate is high, it's hard to believe, families has two or three car. Whether it is the bus or private car is such rapid development, this will bring a lot of problems in road traffic, such as traffic congestion, traffic accident. These problems affect the normal life and travel, it is necessary to carry out management and provide information service for road use advanced technology. Using mobile phone GPS positioning module can obtain the vehicle speed and the basic information, through processing and optimization of information service system, the analysis of data useful, so as to divert traffic, both for the convenience of the user, but also improve the expressway management ability.

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