scholarly journals Micro Electrochemical Milling of Micro Metal Parts with Rotating Ultrasonic Electrode

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6617
Author(s):  
Yong Liu ◽  
Haoran Chen ◽  
Shenghai Wang ◽  
Kan Wang ◽  
Minghao Li ◽  
...  
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Rapid Development ◽  
Three Dimensional ◽  
Machining Performance ◽  
Good Surface ◽  
Anode Dissolution ◽  
Compound Method ◽  
Metal Microstructure ◽  
Electrochemical Milling

With the rapid development of MEMS, the demand for metal microstructure is increasing. Micro electrochemical milling technology (MECM) is capable of manufacturing micro metallic devices or components based on the principle of electrochemical anode dissolution. To improve the capacity of MECM, this paper presents a compound method named ultrasonic vibration-assisted micro electrochemical milling technology (UA-MECM). Firstly, the simulation and mathematical model of UA-MECM process is established to explain the mechanism of ultrasonic vibration on micro electrochemical milling. Then, the effects of ultrasonic parameters, electrical parameters and feedrate on machining localization and surface quality are discussed considering sets of experiments. The surface roughness was effectively reduced from Ra 0.83 to Ra 0.26 µm with the addition of ultrasonic vibration. It turns out that ultrasonic vibration can obviously improve machining precision, efficiency and quality. Finally, two- and three-dimensional microstructures with good surface quality were successful fabricated. It shows that ultrasonic vibration-assisted electrochemical milling technology has excellent machining performance, which has potential and broad industrial application prospects.

Drilling Characteristics of SiC Particle Reinforced Aluminum-Matrix Composites with Ultrasonic Vibration

2010 ◽  
Vol 455 ◽  
pp. 302-306 ◽  
Author(s):  
Xing Xin Xu ◽  
Xiao Hui Zhang ◽  
Chuan Shao Liu ◽  
Bo Zhao
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Rapid Development ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Drilling Process ◽  
Matrix Composites ◽  
Drilling Force ◽  
Vibration Drilling ◽  
Sic Particle

With the rapid development of aviation at home, particle reinforced metal matrix composites (PRMMCs) has been widely applied recently. But at the same time, the difficult machining has gradually been one of the most outstanding bottle-necks that restrict the rapid enhancement of productivity. Here, in virtue of the self-developed ultrasonic drilling equipment, hole-making experiments of common and ultrasonic vibration drilling are performed on SiC particle reinforced aluminum-matrix composites （SiCp/Al）with different content of SiC by using two types of tungsten carbide drill. Drilling characteristics of machining composites with ultrasonic vibration are analyzed from such respects as the composites crush, drilling force, drill wear and hole surface quality. Studies show that, during the ultrasonic vibration drilling process, SiC particle in the composites is prone to break along the crystal connection boundary or suffer ductile fracture under the dynamic ultrasonic impulse, in which the cutting resistance could be reduced and the tool edge could be protected. Thereby, drilling locating precision and hole surface quality could be enhanced, wear of the drill chisel edge effectively improved, and the drilling torque reduced about 30%.

Development of Ultrasonic Vibration Assisted Micro Electrochemical Discharge Machining Tool

2019 ◽  
Vol 12 (4) ◽  
pp. 313-325
Author(s):  
Xiaokun Li ◽  
Yuankai Ren ◽  
Zhiyuan Wei ◽  
Yong Liu
Keyword(s):  
Machine Tool ◽  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Brittle Materials ◽  
Geometric Accuracy ◽  
Machining Performance ◽  
Machining Quality ◽  
Electrochemical Discharge Machining ◽  
Electrochemical Discharge ◽  
Hard And Brittle Materials

Background: The fabrication of microstructures with high machining quality is always difficult when it is concerned with non-conductive hard and brittle materials such as glass and engineering ceramics. It is reported in related papers and patents that Electrochemical Discharge Machining (ECDM) process is a good choice for machining non-conductive, hard and brittle materials. However, the machining performance of ECDM process, especially in the aspect of geometric accuracy and surface quality, needs to be greatly improved. Objective: The purpose of this study was to improve the machining quality of conventional ECDM process by introducing ultrasonic vibration to ECDM process, develop an Ultrasonic Vibration Assisted Micro Electrochemical Discharge Machining (UAECDM) tool, and investigate the improvements of the machining performance by means of comparative experiments. Methods: Firstly, the machining principle of UAECDM was investigated, and the effects of ultrasonic vibration are discussed with the analysis of the micro process. Secondly, the hardware system, which consists of a machine tool body, XY and Z axes, an ultrasonic spindle system and motion control system, was established; and the software system was developed based on the analysis of the overall workflow of the machining process. Finally, comparative experiments, including ECDM drilling, UAECDM drilling, ECDM milling and UAECDM milling, were carried out to reveal the improvements of the machining quality. Results: In the UAECDM group, a micro-hole with the inlet diameter of 133.2µm as well as the 3 × 3 array of micro holes was fabricated on the glass workpiece with 300µm thickness, and a microgroove with the width of 119.2µm was successfully milled on the glass workpiece. It is shown in both microscopic photographs and optical measurements that the microstructures fabricated by UAECDM have better machining quality compared with similar microstructures fabricated by ECDM. Conclusion: Based on comparative experiments and discussions of the results, it has been proved that the machine tool can meet the requirement of the ultrasonic vibration-assisted micro electrochemical discharge machining and can improve the geometric accuracy and surface quality significantly.

scholarly journals Experimental Research on Machining Localization and Surface Quality in Micro Electrochemical Milling of Nickel-Based Superalloy

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 402 ◽  
Author(s):  
Yong Liu ◽  
Yong Jiang ◽  
Chunsheng Guo ◽  
Shihui Deng ◽  
Huanghai Kong
Keyword(s):  
Surface Quality ◽  
Electrochemical Machining ◽  
Nanosecond Pulse ◽  
Machining Parameters ◽  
Pulse Technique ◽  
Nickel Based Superalloy ◽  
Good Surface ◽  
Pulse On Time ◽  
Electrochemical Milling ◽  
Machining Localization

Micro electrochemical machining is becoming increasingly important in the microfabrication of metal parts. In this paper, the machining characteristics of micro electrochemical milling with nanosecond pulse were studied. Firstly, a mathematical model for the localization control of micro electrochemical milling with nanosecond pulse was established. Secondly, groups of experiments were conducted on nickel-based superalloy and the effects of parameters such as applied voltage, pulse on time, pulse period, electrolyte concentration and electrode diameter on machining localization and surface roughness were analyzed. Finally, by using the optimized machining parameters, some 2D complex shapes and 3D square cavity structures with good shape precision and good surface quality were successfully obtained. It was proved that the micro electrochemical milling with nanosecond pulse technique is an effective machining method to fabricate metal microstructures.

scholarly journals Study of ultrasonic vibration–assisted thread turning of Inconel 718 superalloy

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988377
Author(s):  
Yu He ◽  
Zhongming Zhou ◽  
Ping Zou ◽  
Xiaogang Gao ◽  
Kornel F Ehmann
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Inconel 718 ◽  
Gas Turbines ◽  
Tool Path ◽  
Machining Parameters ◽  
Thread Cutting ◽  
Workpiece Surface ◽  
Inconel 718 Superalloy ◽  
The Relationship

With excellent properties, high-temperature superalloys have become the main application materials for aircraft engines, gas turbines, and many other devices. However, superalloys are typically difficult to machine, especially for the thread cutting. In this article, an ultrasonic vibration–assisted turning system is proposed for thread cutting operations in superalloys. A theoretical analysis of ultrasonic vibration–assisted thread cutting is carried out. An ultrasonic vibration–assisted system was integrated into a standard lathe to demonstrate thread turning in Inconel 718 superalloy. The influence of ultrasonic vibration–assisted machining on workpiece surface quality, chip shape, and tool wear was analyzed. The relationship between machining parameters and ultrasonic vibration–assisted processing performance was also explored. By analyzing the motion relationship between tool path and workpiece surface, the reasons for improved workpiece surface quality by ultrasonic vibration–assisted machining were explained.

Current RNA-based Therapeutics in Clinical Trials

2019 ◽  
Vol 19 (3) ◽  
pp. 172-196 ◽  
Author(s):  
Ling-Yan Zhou ◽  
Zhou Qin ◽  
Yang-Hui Zhu ◽  
Zhi-Yao He ◽  
Ting Xu
Keyword(s):  
Clinical Trials ◽  
Rapid Development ◽  
Genetic Diseases ◽  
Three Dimensional ◽  
Therapeutic Effects ◽  
Messenger Rnas ◽  
Small Interfering Rnas ◽  
Rna Modifications ◽  
Guide Rna ◽  
Endogenous Genes

Long-term research on various types of RNAs has led to further understanding of diverse mechanisms, which eventually resulted in the rapid development of RNA-based therapeutics as powerful tools in clinical disease treatment. Some of the developing RNA drugs obey the antisense mechanisms including antisense oligonucleotides, small interfering RNAs, microRNAs, small activating RNAs, and ribozymes. These types of RNAs could be utilized to inhibit/activate gene expression or change splicing to provide functional proteins. In the meantime, some others based on different mechanisms like modified messenger RNAs could replace the dysfunctional endogenous genes to manage some genetic diseases, and aptamers with special three-dimensional structures could bind to specific targets in a high-affinity manner. In addition, the recent most popular CRISPR-Cas technology, consisting of a crucial single guide RNA, could edit DNA directly to generate therapeutic effects. The desired results from recent clinical trials indicated the great potential of RNA-based drugs in the treatment of various diseases, but further studies on improving delivery materials and RNA modifications are required for the novel RNA-based drugs to translate to the clinic. This review focused on the advances and clinical studies of current RNA-based therapeutics, analyzed their challenges and prospects.

Synthesis of high-temperature thermally expandable microcapsules and their effects on foaming quality and surface quality of foamed ABS materials

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 519-527
Author(s):  
Wei Gong ◽  
Xianglin Pei ◽  
Xiaogang Yin ◽  
Daming Ban ◽  
Hai Fu ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Quality ◽  
Volume Fraction ◽  
Crosslinking Agent ◽  
Acrylonitrile Butadiene Styrene ◽  
Foaming Agent ◽  
Blowing Agent ◽  
Good Surface ◽  
Butadiene Styrene

AbstractIn this paper, acrylonitrile and hydroxypropyl acrylate are used as the binary polymerization monomers, and isooctane is used as the foaming agent to prepare high-temperature thermally expandable microcapsules. Analysis of the effect of blowing agent and crosslinking agent on the expansion properties of high-temperature thermally expandable microcapsules, the effects of foaming agent azodicarbonamide (ADCA) and micro-expansion capsule on the surface quality and foaming quality of foamed acrylonitrile–butadiene–styrene (ABS) products were investigated. The foamed product prepared by the high-temperature microcapsule has a good surface quality, the gloss is 52.3, the cell is not easily deformed, and the volume fraction is 4%; the foamed ABS/ADCA material has poor cell uniformity, the cell is easily deformed, the volume fraction is 6.5%, the surface quality is poor, and the gloss is only 8.7.

scholarly journals Experimental Study on Ultrasonic Vibration-Assisted WECDM of Glass Microstructures with a High Aspect Ratio

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 125
Author(s):  
Yan Chen ◽  
Xu Feng ◽  
Gongming Xin
Keyword(s):  
Aspect Ratio ◽  
Ultrasonic Vibration ◽  
High Aspect Ratio ◽  
Rapid Development ◽  
Glass Plate ◽  
Slit Width ◽  
Critical Voltage ◽  
Machining Parameters ◽  
Planar Coil ◽  
Helical Electrode

With the rapid development of micro-electro-mechanical systems (MEMSs), the demand for glass microstructure is increasing. For the purpose of achieving high quality and stable machining of glass microstructures with a high aspect ratio, ultrasonic vibration is applied into the micro-wire electrochemical discharge machining (WECDM), which is proposed as ultrasonic vibration-assisted WECDM with a micro helical electrode. Firstly, the formation of a gas film on the surface of the helical electrode in WECDM machining is simulated, meaning the thickness of the gas film can be reduced by adding suitable ultrasonic amplitude, thus reducing the critical voltage, then the machining localization and stability were enhanced. Then, the micro helical electrode with a diameter of 100 μm is used to carry out sets of experiments that study the influence of ultrasonic amplitude, machining voltage, duty factor, pulse frequency, and feed rate on the slit width. The experimental results show that the machining stability and quality are significantly improved by adding suitable ultrasonic amplitude. When the amplitude was 5.25 μm, the average slit width was reduced to 128.63 μm with a decrease of 20.78%. Finally, with the optimized machining parameters, micro planar coil structure and microcantilever structure with a high aspect ratio were fabricated successfully on the glass plate. It is proved that ultrasonic vibration-assisted WECDM with the micro helical electrode method can meet the requirements of high aspect ratio microstructure machining for hard and brittle materials.

scholarly journals Virtual Archaeology of Death and Burial: A Procedure for Integrating 3D Visualization and Analysis in Archaeothanatology

2021 ◽  
Vol 7 (1) ◽  
pp. 540-555
Author(s):  
Hayley L. Mickleburgh ◽  
Liv Nilsson Stutz ◽  
Harry Fokkens
Keyword(s):  
Spatial Information ◽  
3D Visualization ◽  
Rapid Development ◽  
Three Dimensional ◽  
3D Models ◽  
The Body ◽  
Test Case ◽  
Archaeology Of Death ◽  
Human Burials ◽  
3D Information

Abstract The reconstruction of past mortuary rituals and practices increasingly incorporates analysis of the taphonomic history of the grave and buried body, using the framework provided by archaeothanatology. Archaeothanatological analysis relies on interpretation of the three-dimensional (3D) relationship of bones within the grave and traditionally depends on elaborate written descriptions and two-dimensional (2D) images of the remains during excavation to capture this spatial information. With the rapid development of inexpensive 3D tools, digital replicas (3D models) are now commonly available to preserve 3D information on human burials during excavation. A procedure developed using a test case to enhance archaeothanatological analysis and improve post-excavation analysis of human burials is described. Beyond preservation of static spatial information, 3D visualization techniques can be used in archaeothanatology to reconstruct the spatial displacement of bones over time, from deposition of the body to excavation of the skeletonized remains. The purpose of the procedure is to produce 3D simulations to visualize and test archaeothanatological hypotheses, thereby augmenting traditional archaeothanatological analysis. We illustrate our approach with the reconstruction of mortuary practices and burial taphonomy of a Bell Beaker burial from the site of Oostwoud-Tuithoorn, West-Frisia, the Netherlands. This case study was selected as the test case because of its relatively complete context information. The test case shows the potential for application of the procedure to older 2D field documentation, even when the amount and detail of documentation is less than ideal.

Study on the Surface Quality of Al2O3 Nano-Films by Ion Beam Sputtering Deposition

2011 ◽  
Vol 148-149 ◽  
pp. 54-57
Author(s):  
Xiao Ping Lin ◽  
Yun Dong ◽  
Lian Wei Yang
Keyword(s):  
Surface Quality ◽  
Ion Beam ◽  
Three Dimensional ◽  
Ion Beam Sputtering ◽  
Sputtering Deposition ◽  
Atomic Force ◽  
Beam Sputtering ◽  
Dimensional Growth ◽  
Different Thickness

The Al2O3 nano-films of different thicknesses (1~100nm) were successfully deposited on the monocrystalline Si surface by using ion beam sputtering deposition. The surface topography and the component of nano-films with different thickness were analyzed. The quality of the surface of nano-films was systematically studied. When the films’ thickness increase, the studies by atomic force microscope (AFM), X-ray photoelectron spectrum（XPS） show that the gathering grain continually grows up and transits from acerose cellula by two-dimensional growth to globularity by three-dimensional growth. The elements O, Al and Si were found on the surface of Al2O3 nano-films. With the thickness of the films increasing, the content of Al gradually increases and the intensity peak of Si wears off, the surface quality of the deposited films is ceaselessly improved

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