Minimizing Burrs and Defects on Microstructures with Laser Assisted Micromachining Technology

2016 ◽  
Vol 10 (6) ◽  
pp. 891-898 ◽  
Author(s):  
Shaolin Xu ◽  
◽  
Shinsaku Osawa ◽  
Ryuichi Kobayashi ◽  
Keita Shimada ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
High Efficiency ◽  
Maximum Shear Stress ◽  
Electroless Nickel ◽  
Transient Temperature ◽  
Experimental Conditions ◽  
Optical Components ◽  
Temperature Distributions ◽  
Periodic Microstructures ◽  
Cutting Processes

Molding technology is widely used to manufacture optical components because of its high efficiency. Along with the quick development of miniaturization in industry, the detrimental effects of previously negligible burrs and defects on mold surfaces have become significant to the performance of components, so these problems should be minimized. In this study, a laser assisted micromachining method was developed to solve this problem during the fabrication of periodic microstructures on a molding material of electroless nickel-phosphorus (NiP) plating. The transient temperature distributions of the workpiece under laser irradiation and the change in the maximum shear stress during the laser assisted micromachining process were simulated to set appropriate experimental conditions. Then, periodic micropyramid structures were fabricated by both conventional cutting and the laser assisted cutting processes. Results show that defects largely decreased on machined structures with the assistance of laser irradiation. The decrease in specific cutting force and the change of chips’ morphology were also utilized to analyze the reasons for this improvement.

High-angle Kikuchi patterns

1954 ◽  
Vol 221 (1145) ◽  
pp. 224-242 ◽  
Keyword(s):  
Lithium Fluoride ◽  
High Efficiency ◽  
Cylindrical Specimen ◽  
Angle Of Incidence ◽  
High Angle ◽  
Lead Sulphide ◽  
Marked Contrast ◽  
Experimental Conditions ◽  
Low Intensity ◽  
Glancing Angle

A cylindrical specimen chamber and camera have been used to study the high-angle Kikuchi patterns obtained by reflexion of electrons, of energy 6 to 50 keV, from the cleavage surfaces of crystals with the sodium chloride structure. Angles of scattering ranging from 0 to 164° were covered. The relative intensity of the pattern at different scattering angles was measured using a photographic technique. The intensity distribution was found to become less steep as the energy of the incident electrons decreased. In photographs taken with a large value of the glancing angle of incidence, defect bands were found, starting near the shadow edge of the pattern; these changed to excess bands at higher angles of scattering. The most striking feature of the results is the remarkable intensity and clarity at the highest scattering angles of the pattern produced by crystals such as lead sulphide and potassium iodide, the constituents of which have a relatively high elastic scattering cross-section. In marked contrast, a relatively low intensity and low clarity was found at these angles for lithium fluoride under the same experimental conditions. An investigation of the width of Kikuchi bands, visible over the whole available angular range, showed that the electrons forming these bands had the same energy as that of the incident electrons within the experimental error of 10%. A possible mechanism is discussed by means of which electrons can be diffused through large angles with high efficiency, relative to small angles, and with relatively little loss of energy.

New Development in High Efficiency Deep Grinding

2012 ◽  
Author(s):  
Andre D. L. Batako ◽  
Valery V. Kuzin ◽  
Brian Rowe
Keyword(s):  
Machine Tool ◽  
High Efficiency ◽  
Machining Process ◽  
Depth Of Cut ◽  
Removal Rates ◽  
Workpiece Surface ◽  
New Development ◽  
Cutting Processes ◽  
Selection Of ◽  
Made In

High Efficiency Deep Grinding (HEDG) has been known to secure high removal rates in grinding processes at high wheel speed, relatively large depth of cut and moderately high work speed. High removal rates in HEDG are associated with very efficient grinding and secure very low specific energy comparable to conventional cutting processes. Though there exist HEDG-enabled machine tools, the wide spread of HEDG has been very limited due to the requirement for the machine tool and process design to ensure workpiece surface integrity. HEDG is an aggressive machining process that requires an adequate selection of grinding parameters in order to be successful within a given machine tool and workpiece configuration. This paper presents progress made in the development of a specialised HEDG machine. Results of HEDG processes obtained from the designed machine tool are presented to illustrate achievable high specific removal rates. Specific grinding energies are shown alongside with measured contact arc temperatures. An enhanced single-pole thermocouple technique was used to measure the actual contact temperatures in deep cutting. The performance of conventional wheels is depicted together with the performance of a CBN wheel obtained from actual industrial tests.

scholarly journals Research on Key Technology of Electrochemical Sterilization and Physical Application for Circulating Cooling Water

2021 ◽  
Vol 2083 (2) ◽  
pp. 022068
Author(s):  
Xiaohui Wang ◽  
Chunyan Song ◽  
Xueying Xie ◽  
Nan Zhang ◽  
Ruiqing Guo ◽  
...  
Keyword(s):  
Electric Fields ◽  
Electrode Materials ◽  
High Efficiency ◽  
Thermal Power ◽  
Cooling Water ◽  
Environmentally Friendly ◽  
Research Progress ◽  
Electrode Spacing ◽  
Experimental Conditions ◽  
Circulating Cooling Water

Abstract As a high-efficiency, low-cost, convenient and environmentally friendly sterilization technology, electrochemical disinfection has developed rapidly in recent years. Electrochemical sterilization is an environmentally friendly sterilization technology. The research progress of this technology in the recent 30 years in sterilization mechanism and electrode materials is summarized. The mechanism of electrochemical sterilization includes the chemical effects of active chlorine, active intermediates, copper or silver ions, and the physical effects of electric fields; the electrode materials used are titanium anode, carbon cathode, and anode. The article combined with electrochemical equipment in a thermal power plant cold open circulating cooling water treatment experiment. Experimental research found that under the conditions of current density of 120A/m2, residence time of 10s, and electrode spacing of 1.8cm, the bactericidal effect can reach 97%. Under certain experimental conditions and a certain period of time, the total number of heterogeneous bacteria in the circulating cooling water after treatment can be effectively inhibited.

The Transient Temperature Distribution in a Slab Subject to Thermal Radiation

1965 ◽  
Vol 87 (1) ◽  
pp. 117-130 ◽  
Author(s):  
R. D. Zerkle ◽  
J. Edward Sunderland
Keyword(s):  
Temperature Distribution ◽  
Thermal Radiation ◽  
Radiant Heat ◽  
Analog Computer ◽  
Graphical Form ◽  
Transient Temperature ◽  
Transient Temperature Distribution ◽  
Temperature Distributions ◽  
Approximate Analytical Solutions ◽  
Wide Range

The transient, one-dimensional temperature distribution is determined for a slab, insulated on one face, and subjected to thermal radiation at the other face. The slab is initially at a uniform temperature and is assumed to be homogeneous, isotropic, and opaque; the physical properties are assumed to be independent of temperature. Transient temperature distributions for both heating and cooling situations are obtained by means of a thermal-electrical analog computer. A diode limiter circuit is used to simulate the nonlinear radiant heat flux. The transient temperature distributions are presented in a dimensionless, graphical form for a wide range of variables. Approximate analytical solutions are also given which complement and extend the solution charts over ranges of parameters not covered in the charts.

scholarly journals An Erosion-Corrosion Investigation of Coated Steel for Applications in the Oil and Gas Field, Based on Bipolar Electrochemistry

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 92
Author(s):  
Claudio Mele ◽  
Francesca Lionetto ◽  
Benedetto Bozzini
Keyword(s):  
Oil And Gas ◽  
Electroless Nickel ◽  
Solid Particles ◽  
Bipolar Electrode ◽  
Experimental Conditions ◽  
Gas Field ◽  
Experimental Apparatus ◽  
Erosion Corrosion ◽  
Oil And Gas Field ◽  
Sprayed Coating

In this research, a simple experimental apparatus based on a bipolar electrode (BPE) configuration was set up, in order to tackle erosion-corrosion problems of materials of interest in the oil and gas field. As a case study, the resistance to erosion and corrosion of carbon steel samples coated by Electroless Nickel Plating and by thermo-sprayed coating with the high velocity oxy fuel (HVOF) process was investigated. The main objective was to demonstrate if this simple, contactless technique could be applied to effectively discriminate the erosion-corrosion behavior of different materials in a vast range of experimental conditions. In fact, by means of polarization curves, visual inspection and morphological analysis by scanning electron microscope (SEM), the effects due to erosion-corrosion by solid particles, by fluid and those due to simple erosion were evaluated.

Laser exfoliation of 2D black phosphorus nanosheets and their application as a field emitter

RSC Advances ◽  
2016 ◽  
Vol 6 (113) ◽  
pp. 112103-112108 ◽  
Author(s):  
Sachin R. Suryawanshi ◽  
Mahendra A. More ◽  
Dattatray J. Late
Keyword(s):  
Laser Irradiation ◽  
Field Emission ◽  
Black Phosphorus ◽  
Two Dimensional ◽  
Experimental Conditions ◽  
Field Emitter ◽  
Emission Performance ◽  
One Step ◽  
Field Emission Performance

Highly crystalline two dimensional (2D) few layered black phosphorus (BP) nanosheets have been synthesized via a one step facile laser irradiation technique under optimized experimental conditions. The BP material shows promising field emission performance.

Design and Implementation of an Intensified Coprecipitation Reactor for the Treatment of Liquid Radioactive Wastes

2013 ◽  
Author(s):  
Julie Flouret ◽  
Yves Barré ◽  
Hervé Muhr ◽  
Edouard Plasari
Keyword(s):  
Reaction Zone ◽  
Residence Time ◽  
Flow Rate ◽  
High Efficiency ◽  
Solid Phase ◽  
Continuous Process ◽  
Decontamination Factor ◽  
Barium Nitrate ◽  
Molar Ratio ◽  
Experimental Conditions

The coprecipitation is a robust and inexpensive process for the treatment of important volumes of low and intermediate radioactive level liquid wastes. Its major inconvenient is the huge volume of sludge generated. The purpose of this work is to optimize the industrial coprecipitation continuous process by achieving the following objectives: - maximize the decontamination efficiency; - minimize the volume of sludge generated by the process; - reduce the treatment cost decreasing the installation volume. An innovative reactor with an infinite recycling ratio was therefore designed. It is a multifunctional reactor composed of two zones: a perfectly mixed precipitation zone and a classifier to perform liquid-solid separation. The experiments are focused on the coprecipitation of strontium by barium sulphate. The effluent containing sulphate ions and the barium nitrate solution are injected in the reaction zone where strontium and barium coprecipitate as sulphates. The produced solid phase is returned into the reaction zone by the classifier and goes out slowly from the reactor bottom with a residence time much higher than the liquid phase. This creates both a high concentration of solid phase in the reaction zone and a high efficiency of decontamination. The experimental conditions simulate the industrial effluents. The total treatment flow rate is 17 L/h, with an effluent flow rate of 16 L/h and a reactive flow rate of 1 L/h, hence a mean residence time of 10 minutes. In these experimental conditions, the molar ratio sulphate/barium after mixing corresponds to 4.9. These conditions are used in the reprocessing plant of La Hague. The decontamination factor reached in these experimental conditions is excellent: DF = 1500. The decontamination factor obtained with the classical continuous process is only equal to 60. Different process parameters are studied in order to optimize the reactor/classifier: residence time, barium nitrate flow rate and racking flow rate. The decrease of barium nitrate flow rate reduces the volume of sludge generated by the process keeping a high efficiency of strontium decontamination: DF = 400. An excess of sulphate is necessary to perform an efficient decontamination, but the molar ratio sulphate/barium can be reduced to 3 instead of 4.9 used industrially. The reactor/classifier also represents an efficient device for the coprecipitation process intensification. Indeed, it can sensibly reduce the final installation size while treating important volume of effluents. This innovative reactor optimizes both the decontamination efficiency of radioactive liquid wastes and the reduction of sludge volume. A reduction of sulphate ions in the discharge is also possible, which is environmentally friendly.

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