scholarly journals A dual material removal mechanism for clearing of obstructed holes via electrical discharge machining

2021 ◽  
Author(s):  
Monica Castro-Palacios ◽  
Shamraze Ahmed ◽  
Nuhaize Ahmed ◽  
James W. Murray ◽  
Alistair Speidel ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Dual Material

On Correlation of Pulses and Tool Elongations at Micro-Electrical Discharge Machining Aided by Ultrasonics

2015 ◽  
Vol 809-810 ◽  
pp. 309-314
Author(s):  
Daniel Ghiculescu ◽  
Nicolae Marinescu ◽  
Tomasz Klepka ◽  
Nicoleta Carutasu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Micro Electrical Discharge Machining ◽  
Machining Strategy ◽  
Element Method

The paper deals with Finite Element Method (FEM) of thermal and mechanical-hydraulic components of material removal mechanism at micro-electrical discharge machining aided by ultrasonics (μEDM+US), due to EDM and US contribution. The dimensions of craters produced by single discharges under μEDM+US conditions are determined with different pulse durations in order to establish a machining strategy with correlation of pulses and tool elongations.

Monitoring of material-removal mechanism in micro-electrical discharge machining by pulse classification and acoustic emission signals

2020 ◽  
pp. 095440542092756 ◽  
Author(s):  
Kanka Goswami ◽  
GL Samuel
Keyword(s):  
Acoustic Emission ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Distribution Analysis ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Time Frequency ◽  
Feed Forward Back Propagation ◽  
Micro Electrical Discharge Machining

Micro-electrical discharge machining is a stochastic process where the interaction between the materials and the process parameters are difficult to understand. Monitoring of the process becomes necessary to achieve the dimensional accuracy of the micro-featured components. Although thermo-mechanical erosion is the most accepted material-removal mechanism, it fails to explain the material removal with very short pulse duration. Alternative postulate like electrostatic force-induced stress yielding provides a stronger argument, rising ambiguity over the material-removal process in the micro-electrical discharge machining regime. In this work, it was found that the stress waves released from the material during micro-electrical discharge-machining process indicate material removal by mechanical deformation and fracture mechanism. These stress waves were captured using the acoustic emission sensor. The discharge pulses were captured by voltage measurement and classified using voltage gradient and machining time duration into three major categories, open pulse, normal pulse and arc pulse. The acoustic emission signal features were extracted and identified by time–frequency–energy distribution analysis. A feed-forward back-propagation neural network mapping of the pulse instances was performed with the obtained acoustic emission signature. The time–frequency–energy distribution analysis of the acoustic emission and the scanning electron microscope images of the craters provide conclusive evidence that the material is removed by mechanical stress and fracture. The feed-forward back-propagation network model was trained to predict the discharge categories of the pulse instances with AE signal inputs which can be used for monitoring the material-removal mechanism in micro-electrical discharge machining operation.

scholarly journals Electrical Discharge Machinable Ytterbia Samaria Co-Stabilized Zirconia Tungsten Carbide Composites

Ceramics ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 408-421
Author(s):  
Maximilian Rapp ◽  
Andrea Gommeringer ◽  
Frank Kern
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Tungsten Carbide ◽  
Electrical Discharge ◽  
Material Removal ◽  
Removal Mechanism ◽  
Composite Ceramics ◽  
Material Removal Mechanism ◽  
Stabilized Zirconia ◽  
Electrically Conductive

Composite ceramics of stabilizer oxide coated ytterbia-samaria costabilized zirconia (1.5Yb1.5Sm-TZP) and 24–32 vol% of tungsten carbide as an electrically conductive dispersion were manufactured by hot pressing at 1300–1400 °C for 2 h at 60 MPa pressure. The materials were characterized with respect to microstructure, phase composition, mechanical properties and electrical discharge machinability by die sinking. Materials with a nanocomposite microstructure and a strength of up to 1700 MPa were obtained. An attractive toughness of 6–6.5 MPa√m is achieved as 40–50% of the zirconia transformed upon fracture. The materials show fair material removal rates of 1 mm³/min in die sinking. Smooth surfaces indicate a material removal mechanism dominated by melting.

Modeling and Analyzing on Nonuniformity of Material Removal in Chemical Mechanical Polishing of Silicon Wafer

2004 ◽  
Vol 471-472 ◽  
pp. 26-31 ◽  
Author(s):  
Jian Xiu Su ◽  
Dong Ming Guo ◽  
Ren Ke Kang ◽  
Zhu Ji Jin ◽  
X.J. Li ◽  
...  
Keyword(s):  
Silicon Wafer ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Removal Mechanism ◽  
Particle Movement ◽  
Material Removal Mechanism ◽  
The Relationship ◽  
Nonuniform Material

Chemical mechanical polishing (CMP) has already become a mainstream technology in global planarization of wafer, but the mechanism of nonuniform material removal has not been revealed. In this paper, the calculation of particle movement tracks on wafer surface was conducted by the motion relationship between the wafer and the polishing pad on a large-sized single head CMP machine. Based on the distribution of particle tracks on wafer surface, the model for the within-wafer-nonuniformity (WIWNU) of material removal was put forward. By the calculation and analysis, the relationship between the motion variables of the CMP machine and the WIWNU of material removal on wafer surface had been derived. This model can be used not only for predicting the WIWNU, but also for providing theoretical guide to the design of CMP equipment, selecting the motion variables of CMP and further understanding the material removal mechanism in wafer CMP.

Fundamental study on material removal mechanism in single-crystal germanium

2021 ◽  
pp. 103773
Author(s):  
Ruiwen Geng ◽  
Xiaojing Yang ◽  
Qiming Xie ◽  
Jianguo Xiao ◽  
Wanqing Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Material Removal ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Fundamental Study
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