Learning nanotechnology through experimentation: carbon nanotube manufacturing using an electric discharge machine

2012 ◽  
Vol 1 (3) ◽  
pp. 281-287 ◽  
Author(s):  
Nebojsa Jaksic
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Student Perceptions ◽  
Electric Discharge ◽  
Arc Discharge ◽  
Removal Rate ◽  
Electric Discharge Machining ◽  
Undergraduate Engineering ◽  
The Cost ◽  
Lecture Experiment

AbstractA novel nanotechnology laboratory experiment for a required junior/senior undergraduate engineering course, Engineering of Manufacturing Processes, is described and implemented. The experiment demonstrates a process of manufacturing carbon nanotubes using a method representing a variation on arc discharge. Carbon nanotubes are synthesized in oil by electric discharge machining using two graphite electrodes. The results are compared to a known empirical formula for material removal rate in electric discharge machining. A cost analysis of the process, determining the cost of as produced carbon nanotubes is performed. This 2-h experiment is complemented with a single 2-h lecture on nanotechnology creating a lecture-experiment nanotechnology module. Student learning outcomes for the module are developed, assessed, and analyzed. The results show a significant improvement in students’ knowledge. Student perceptions about nanotechnology, carbon nanotube manufacturing, and the need for life-long learning are assessed. Pedagogical justifications and sustainability of the nanotechnology lecture-experiment module within an undergraduate engineering curriculum are addressed.

Study of Field Emission Behavior of Carbon Nanotubes with Different Sources

2002 ◽  
Vol 728 ◽  
Author(s):  
Mark Ching-Cheng Lin ◽  
M.S. Lai ◽  
H. J. Lai ◽  
M. H. Yang ◽  
B.Y. Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Emission ◽  
Arc Discharge ◽  
Metal Catalyst ◽  
Microstructural Investigation ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Different Sources

AbstractThe field emission properties of carbon nanotubes (CNTs) from various sources are investigated for the application of field emission displays. Comparisons are made between graphite with Ni metal as catalyst and polycyclic aromatic hydrocarbon as precursor by the arc discharge method. Cathode deposits are examined using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) to determine microstructure. Carbon structure is studied using Raman spectroscopy. Electron field emission characteristics are measured with the diode method at 10-6 torr pressure. In this study, SEM micrographs of cathode deposits show dense random fiber-like carbon nanotubes. The HRTEM images clearly exhibit characteristic features of multiwalled carbon nanotubes. Microstructural investigation provides evidence that both the metal catalyst and the precursor can be used to synthesize carbon nanotubes. The Raman spectrum shows a stronger peak at about 1580 cm-1 indicating formation of a well-graphitized carbon nanotube. The degree of carbon nanotube graphitization is high and is in good agreement with the HRTEM result. From field emission measurements, the lowest onset field is about 1.0 V/μm and can be attributed to highly sharp tips and the high density of carbon nanotubes. Based on microstructure characterization and field emission measurements, the influence on field emission properties including turn on voltage and threshold voltage of carbon nanotubes synthesized from different sources is discussed.

scholarly journals A Simple Procedure for Searching Pareto Optimal Front in Machining Process: Electric Discharge Machining

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ushasta Aich ◽  
Simul Banerjee
Keyword(s):  
Electric Discharge ◽  
Removal Rate ◽  
Simple Procedure ◽  
Operating Conditions ◽  
Machining Process ◽  
Optimum Process ◽  
Pareto Optimal ◽  
Electric Discharge Machining ◽  
Optimum Process Parameter ◽  
Pareto Optimal Front

Optimum control parameter setting in complex and stochastic type processes is one of the most challenging problems to the process engineers. As such, effective model development and determination of optimal operating conditions of electric discharge machining process (EDM) are reasonably difficult. In this apper, an easy to handle optimization procedure, weight-varying multiobjective simulated annealing, is proposed and is applied to optimize two conflicting type response parameters in EDM—material removal rate (MRR) and average surface roughness (Ra) simultaneously. A solution set is generated. The Pareto optimal front thus developed is further modeled. An inverse solution procedure is devised so that near-optimum process parameter settings can be determined for specific need based requirements of process engineers. The results are validated.

Nano Graphite Powder Assisted Electric Discharge Machining Characteristics of ZM21 Magnesium Alloy

2015 ◽  
Vol 787 ◽  
pp. 406-410
Author(s):  
S. Santosh ◽  
S. Javed Syed Ibrahim ◽  
P. Saravanamuthukumar ◽  
K. Rajkumar ◽  
K.L. Hari Krishna
Keyword(s):  
Magnesium Alloy ◽  
Material Removal Rate ◽  
Electric Discharge ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Parameters ◽  
Electric Discharge Machining ◽  
Zm21 Magnesium Alloy ◽  
Pulse On Time ◽  
Pulse Off Time

Magnesium alloys are used in many applications, particularly in orthopaedic implants are very difficult to machine by conventional processes because of their complex 3D structure and limited slip system at room temperature. Hence there is an inherent need for alternative processes for machining such intricate profiles. Electric Discharge Machining is growing rapidly in tool rooms, die shops and even in general shop floors of modern industries to facilitate complex machining for difficult-to-machine materials and provide better surface integrity. Therefore, the use of electric discharge machining on ZM21 magnesium alloy is attempted in this paper. Nanographite powder is added for machining zone to enhance the electrical conductivity of EDM oil by way it improves the machining performance. Machining parameters such as the current, pulse on time and pulse off time were process parameters to explore their effects on the material removal rate and tool wear rate. It is observed that, an increased material removal rate was due to the enhanced electrical and thermal conductivity of the EDM oil.

Electric discharge sawing of hybrid metal matrix composites

2015 ◽  
Vol 231 (10) ◽  
pp. 1775-1782 ◽  
Author(s):  
Ravinder Kumar ◽  
Inderdeep Singh
Keyword(s):  
Material Removal Rate ◽  
Electric Discharge ◽  
Metal Matrix ◽  
Material Removal ◽  
Removal Rate ◽  
Electric Discharge Machining ◽  
Debris Accumulation ◽  
Carbon Particles ◽  
Hybrid Metal Matrix Composite ◽  
Sawing Process

Electric discharge sawing process is a novel process for the enrichment of capabilities of electric discharge machining. The process has been developed to cut materials at greater depths where the effect of flushing becomes ineffective. During electric discharge machining at greater depths, ineffective flushing prevents debris and carbon particles from leaving the machining zone and gets accumulated in the sparking zone reducing the spark efficiency. This reduces material removal rate and causes arcing or short circuiting which may damage the workpiece and/or tool surface. In the present experimental endeavor, a new process capable of preventing debris accumulation during machining of slots at large depth and subsequently increasing material removal rate has been developed. In the process, a reciprocating motion is given to the tool blade similar to the power hacksaw blade. An experimental investigation based on central composite design has been conducted on hybrid metal matrix composite to evaluate the effect of input parameters on material removal rate and tool wear rate. It has been found that the electric discharge sawing process is quick and effective as compared to the conventional cutting process.

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