scholarly journals Investigation on Orbital EDM for Double-Hole Thin Wall of Integrated Flexible Joint

2021 ◽  
Author(s):  
Yang Liu ◽  
Yunlong Du ◽  
Weifeng Li ◽  
Yerui Feng ◽  
Yongfeng Guo
Keyword(s):  
Electrical Discharge Machining ◽  
Signal To Noise Ratio ◽  
Orthogonal Experiment ◽  
Cutting Tools ◽  
Thin Wall ◽  
Average Thickness ◽  
Flexible Joint ◽  
Processing Cost ◽  
Key Factor ◽  
Circular Holes

Abstract The thin neck structure of integrated flexible joint is the key factor to realize high-precision navigation in dynamically tuned gyroscope. The thin neck structure is composed of two adjacent circular holes and the thin wall between the two holes. The thin wall is easy to deform under the external force and vibration exerted by the tool when using traditional machining methods such as drilling and boring, and the cutting tools are easily to be damaged for the machining of small holes in superhard materials, inducing high processing cost. Aiming at these problems, the machining method of double-hole thin wall in the step-by-step orbital electrical discharge machining (EDM) with a high rotation speed electrode is proposed. The procedure for EDM of double-hole flexible thin wall is designed, and the process parameters of each step machining are optimized using orthogonal experiment and signal-to-noise ratio analysis. The machining experiments of double-hole thin wall of 3J33B material are proceed using the optimized parameters. The results show that the hole diameter of the double-hole flexible thin wall is 2 mm, the hole depth is 8mm, and the average thickness of the thin wall is about 46.5 μm. The thickness range between the measured point and the average is 1.55 μm, that compared with average thickness of 46.5 μm, the error is less than 3%, the overall thickness is uniform relatively.

An Investigation on Machining Power of EN-AC 48000 Aluminum Alloy Used in Automotive and Aerospace Industries

2009 ◽  
Vol 83-86 ◽  
pp. 704-710 ◽  
Author(s):  
H. Shahali ◽  
Hamid Zarepour ◽  
Esmaeil Soltani
Keyword(s):  
Signal To Noise Ratio ◽  
Cutting Tools ◽  
Tool Material ◽  
Polycrystalline Diamond ◽  
Dimensional Accuracy ◽  
Machining Parameters ◽  
Anova Analysis ◽  
Essential Parameter ◽  
Cutting Velocity ◽  
Coated Carbide

In this paper, the effect of machining parameters including cutting velocity, feed rate, and tool material on machining power of EN-AC 48000 aluminium alloy has been studied. A L27 Taguchi's standard orthogonal array has been applied as experimental design to investigate the effect of the factors and their interaction. Twenty seven machining tests have been accomplished with two random repetitions, resulting in fifty four experiments. EN-AC 48000 is an important alloy in automotive and aerospace industries. Machining of this alloy is of vital importance due to build-up edge and tool wear. Machining power is an essential parameter affecting the tool life, dimensional accuracy, and cutting efficiency. Three types of cutting tools including coated carbide (CD 1810), uncoated carbide (H10), and polycrystalline diamond (CD10) have been used in this study. Statistical analysis has been employed to study the effect of factors and their interactions using ANOVA analysis. Moreover, optimal factor levels have been presented using signal to noise ratio (S/N) analysis. Also, regression model have been provided to predict the machining power. Finally, the results of confirmation tests have been presented to verify and compare the adequacy of the predictive models.

scholarly journals The Effects of Manifest Residual Variances, Indicator Communality, and Sample Size on the χ2-Test Statistic of the Metric Invariance Model

2019 ◽  
Author(s):  
Eric Klopp ◽  
Stefan Klößner
Keyword(s):  
Sample Size ◽  
Measurement Invariance ◽  
Signal To Noise Ratio ◽  
Practical Implication ◽  
Residual Variance ◽  
Test Statistic ◽  
Monte Carlo Studies ◽  
Key Factor ◽  
Metric Measurement ◽  
Invariance Model

In this contribution, we investigate the effects of manifest residual variance, indicator communality and sample size on the χ2-test statistic of the metric measurement invariance model, i.e. the model with equality constraints on all loadings. We demonstrate by means of Monte Carlo studies that the χ2-test statistic relates inversely to manifest residual variance, whereas sample size and χ2-test statistic show the well-known pro- portional relation. Moreover, we consider indicator communality as a key factor for the size of the χ2-test statistic. In this context, we introduce the concept of signal-to-noise ratio as a tool for studying the effects of manifest residual error and indicator commu- nality and demonstrate its use with some examples. Finally, we discuss the limitations of this contribution and its practical implication for the analysis of metric measurement invariance models.

Fabrication of Micropins Using Micro Turning Tools

2012 ◽  
Vol 523-524 ◽  
pp. 76-80 ◽  
Author(s):  
Takuya Furukawa ◽  
Yosuke Nomura ◽  
Kazuyuki Harada ◽  
Kai Egashira
Keyword(s):  
Tungsten Carbide ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Cutting Tools ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Tool Breakage ◽  
Micro Cutting ◽  
Hard Materials ◽  
Micro Turning

The turning of straight micropins with a diameter smaller than 10 µm, which has not been reported so far, was carried out using micro turning tools made of cemented tungsten carbide. Tools of 50 µm diameter were fabricated by electrical discharge machining, which is suitable for fabricating micro cutting tools because it can deal with hard materials and carry out micromachining. A turning machine designed especially for micro turning tools was used in the experiments. A brass workpiece was turned using a tool with a length of cut of 100 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 10–11 µm. As a result, a straight micropin of 7.5 µm diameter and 80 µm length was successfully turned. Furthermore, turning was also performed using a tool with a length of cut of 50 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 8.5–20 µm to fabricate a straight micropin of 3 µm diameter and 30 µm length. This micropin is the pin with the smallest ever diameter fabricated by turning, to the best of our knowledge, indicating the possibility of further minimization of the machinable size in turning. Turning properties were also investigated to determine the maximum depth of cut and feed speed that can be employed without tool breakage.

Research on Micro-Size Electrical Discharge Machining Polycrystalline Diamond

2019 ◽  
Vol 943 ◽  
pp. 14-19 ◽  
Author(s):  
Yun Hai Jia ◽  
Jian Mei Guo ◽  
Yan Guo ◽  
Fan Yu
Keyword(s):  
Pulse Duration ◽  
High Efficiency ◽  
Electrical Discharge Machining ◽  
Pulse Discharge ◽  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
Green Manufacturing ◽  
Single Pulse ◽  
Pit Depth ◽  
Thermal Influence

With the demand of modern cutting technology for ‘high efficiency, precise, flexibility and green manufacturing’, polycrystalline diamond materials as cutting tools have been widely used in automobile, aerospace and non-metal processing. Electro-spark erosion is one of the most effective ways to machine polycrystalline diamond materials. Single pulse discharge is one of the research foundations of micro-EDM. Using 2 micron granularity polycrystalline diamond as experiment material, the influence of single pulse discharge technology on the removal efficiency of materials was studied, such as pit radius, pit depth and radius-depth ratio, etc. The experimental results show that, with the extension of the pulse duration, the radius of the discharge pit begins to increase rapidly, then slowly increases, and finally to slow down; while the radius of thermal influence zone increases rapidly and then continues to increase slowly. With the extension of pulse duration, the ratio of pit depth to radius changes within the range of 0.05 ~ 0.25, which shows a downward trend basically.

Evaluation of the cutting forces, the surface roughness, and the tool wear characteristics during machining of cobalt-based superalloy Haynes 188 with ceramic cutting tool

2021 ◽  
pp. 095440892110480
Author(s):  
Abdullah Altin
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Cutting Forces ◽  
Cutting Tool ◽  
Signal To Noise Ratio ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Signal To Noise ◽  
Ceramic Cutting Tool ◽  
Cutting Speeds

In this research, we had studied the sensitivity for machining of cobalt-based superalloy Haynes 188 with ceramic cutting tool. The investigation had focused on the effects of the cutting speed, on the cutting forces, and on the surface roughness based on Taguchi’s experimental design. The effects of machining parameters were determined using Taguchi’s L27 orthogonal array. The signal-to-noise ratio was calculated for the average of surface roughness and the cutting forces, and the smaller were used to determine the optimal cutting conditions. The analysis of variance and the signal-to-noise ratio had effects on the parameters on both surface roughness and cutting. Three different types of cutting tools had been used in the experiment, namely KYON 4300, KYS 25, and KYS 30. The cutting force of Fz was considered to be the main cutting force. Depending on the material which had been used as cutting tool, the Fz had the lowest cutting speed and the lowest surface roughness with the KYS25 ceramic tool. The cutting force and the surface roughness of KYON 4300 cutting tool had shown better performance than other cutting tools. The flank wear and notch were found to be more effective in the experiments. The long chips were removed at low and medium cutting speeds, while the sawdust with one edge and narrow pitch at high cutting speeds was obtained.

Study on the Experimental of the Electrical Discharge Machining Titanium Alloy on Gas Dielectric

2013 ◽  
Vol 644 ◽  
pp. 171-174 ◽  
Author(s):  
Shuo Guo Zhao ◽  
Xiao Min Yao ◽  
Rui Li
Keyword(s):  
Titanium Alloy ◽  
Electrical Discharge ◽  
Pulse Width ◽  
Electrical Discharge Machining ◽  
Supply Voltage ◽  
Orthogonal Experiment ◽  
Great Influence ◽  
Gas Processing ◽  
Low Supply Voltage ◽  
Processing Properties

In order to know the processing properties of the Electrical Discharge Machining titanium alloy on gas dielectric. Firstly, this paper does comparing experiment of EDM in gas processing titanium alloy. The results indicate that electrode dissipation is low with equifrequence square wave, positive polarity and low supply voltage to machining titanium alloy when pulse width is narrow. Secondly, this paper has done the orthogonal experiment and the variance analysis of experimental results, Its result shows that pulse width and peak current have a great influence on the machining efficiency .

Impact Analysis of Electrode Material on Electrical Discharge Machining Polycrystalline Diamond Processing

2013 ◽  
Vol 441 ◽  
pp. 36-39
Author(s):  
Yun Hai Jia
Keyword(s):  
Surface Roughness ◽  
Layer Thickness ◽  
Electrode Material ◽  
Electrical Discharge ◽  
Electrode Materials ◽  
Cutting Tool ◽  
Electrical Discharge Machining ◽  
Surface Effect ◽  
Cutting Tools ◽  
Process Conditions

The electrode material plays a very important role in the electric discharge machining, affects the electrical discharge machining efficiency and machining surface quality. Experiment testing and materials analysis as the primary method, affect layer thickness and workpiece surface roughness value as evaluation indexes. PCD cutting tool samples were electrical discharge machined using copper electrodes and graphite electrodes respectively. After machining, the PCD cutting tool samples' surfaces were analyzed by X ray diffraction, the surfaces appearances were observed under the scanning electron microscope, and the surface roughness values were measured by roughness measuring instrument. PCD samples' surface effect layer thickness values and surface roughness values, affect layer distribution structure was statically analyzed in typical EDM process conditions with different electrode materials. Summary electrode material effect on PCD cutting tools in EDM processing. Provides an important experimental basis for designing technics of precision and highly efficient electrical discharge machining PCD cutting tools.

scholarly journals Dynamic Study of Thin Wall Part Turning

2011 ◽  
Vol 223 ◽  
pp. 591-599 ◽  
Author(s):  
Philippe Lorong ◽  
Arnaud Larue ◽  
Alexis Perez Duarte
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Thin Wall ◽  
Planning Stage ◽  
Cutting Test ◽  
Process Reliability ◽  
Key Factor ◽  
Simulation Parameters ◽  
And Control ◽  
Thin Wall Part

The numerical simulation of machining process is a key factor in the control of parts machining process. Its development aims at improving the process reliability and reduces the time spent during the process planning stage. In this context, we use a specific time domain simulation allowing modeling the dynamics of a thin wall part turning operation. After having introduced the basics of the proposed approach we present a specific cutting test that has been designed to specifically measure and control the dynamics of the part and the cutting conditions of a finishing toolpath. The influences of the cutting speed and damping coefficient on the chatter occurrence are discussed. In order to better control the simulation uses, an analysis of the simulation parameters influences on the simulated results is proposed.

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