Next-Generation, Super-Hard-to-Process Substrates and Their High-Efficiency Machining Process Technologies Used to Create Innovative Devices

SiC, GaN, and diamond are known as super-hard-to-process substrate for next-generation green devices. In this paper, we report on some breakthrough in developing highly efficient processing for such hard-to-process materials, for which we propose improvements in conventional processing, and innovative processing. As part of our project, we developed a “dilatancy pad®” that can efficiently produce high-quality surfaces as well as a high-rigidity, high-speed and high-pressure processing machine. We also designed and prototyped “plasma fusion CMP®,” which is an innovative processing technology fusing CMP (Chemical Mechanical Polishing) with P-CVM (Plasma Chemical Vaporization Machining) to machine super-hard diamond substrates that are considered indispensable for future devices. Before the advent of “singularities” by 2045, super-hard-to-process substrates and ultra-precision polishing technology will become more and more essential.

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Ultra-High Speed Grinding Using a CBN Wheel for a Mirror-Like Surface Finish

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.291-292.67 ◽

2005 ◽

Vol 291-292 ◽

pp. 67-72 ◽

Cited By ~ 2

Author(s):

M. Ota ◽

T. Nakayama ◽

K. Takashima ◽

H. Watanabe

Keyword(s):

Surface Finish ◽

High Speed ◽

High Efficiency ◽

Ground Surface ◽

Machining Process ◽

Grinding Wheel ◽

Cbn Wheel ◽

Ultra High Speed ◽

High Speed Grinding ◽

Grinding Conditions

There are strong demands for a machining process capable of reducing the surface roughness of sliding parts, such as auto parts and other components, with high efficiency. In this work, we attempted to grind hardened steel to a mirror-like surface finish with high efficiency using an ultra-high speed grinding process. In the present study, we examined the effects of the work speed and the grinding wheel grain size in an effort to optimize the grinding conditions for accomplishing mirror-like surface grinding with high efficiency. The results showed that increasing the work speed, while keeping grinding efficiency constant, was effective in reducing the work affected layer and that the grinding force of a #200 CBN wheel was lower than that of a #80 CBN wheel. Based on these results, a high-efficiency grinding step with optimized grinding conditions was selected that achieved excellent ground surface quality with a mirror-like finish.

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High Efficiency Machining for Integral Shaping from Simplicity Materials Using Five-Axis Machine Tools

International Journal of Automation Technology ◽

10.20965/ijat.2016.p0804 ◽

2016 ◽

Vol 10 (5) ◽

pp. 804-812 ◽

Cited By ~ 2

Author(s):

Makoto Yamada ◽

◽

Tsukasa Kondo ◽

Kai Wakasa

Keyword(s):

Machine Tools ◽

High Speed ◽

High Efficiency ◽

Cutting Process ◽

Machining Process ◽

Rough Machining ◽

Convex Shape ◽

Simple Material ◽

Voxel Model ◽

Five Axis

In the integrally shaping process from a simple material shape to an objective shape, it is necessary to reduce the time required for the machining process in order to improve cost savings and the effectiveness of mass production. For the purpose of achieving high efficiency in the integral shaping from simplicity materials, we have focused on a rough cutting process that requires the most time in the manufacturing process. The purpose of this research is to propose a method for realizing high-speed rough machining using five-axis machine tools with a voxel model, and confirm the high efficiency of the rough cutting. In this research, we use five-axis controlled machine tools for material machining, and suggest two machining methods for the rough cutting process using the voxel model. The first method derives the tool posture where the cutting removal quantity becomes the maximum; this method also carries out a rough cutting process via 3+2 axis controlled machining. The other method carries a complete convex shape that includes the required shape, and simultaneously machines via five-axis machining based on the complete convex shape. This paper demonstrates the 3+2 axis control machining method that uses the voxel model to perform the rough machining process with high efficiency, and the simultaneous five-axis control machining method that uses a complete convex shape model for rough machining. We confirm the results with a computer simulation and actual machining experiments.

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Research on Chemical Mechanical Polishing for Silicon Nitride Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.375-376.283 ◽

2008 ◽

Vol 375-376 ◽

pp. 283-287

Author(s):

Cong Rong Zhu ◽

Ju Long Yuan ◽

Qin Xu ◽

Bing Hai Lv

Keyword(s):

Silicon Nitride ◽

Chemical Mechanical Polishing ◽

Research Result ◽

Surface Profile ◽

Mechanical Polishing ◽

Machining Process ◽

Good Thermal Stability ◽

Nitride Ceramics ◽

Ultra Precision ◽

Small Density

Silicon nitride ceramics materials have excellent properties such as small density, high rigidity, high Young's modulus, high wearability, good thermal stability and chemical stability, which make it become one of the most appropriate materials for rollers of high precision bearing. Chemical Mechanical Polishing (CMP) technology is employed to have an ultra-precision machining process for silicon nitride ceramics materials workpiece and the effects of workpiece surface roughness in different abrasive are discussed in this research. The XRD and SEM technology are used to take phase analysis and surface profile detection for the finishing workpiece polished with CeO2 abrasive. The chemical reaction mechanism and the material remove mechanism of silicon nitride ceramics materials in CMP process with CeO2 abrasive are both analysed and discussed in this paper. The research result shows that an extremely smooth surface of silicon nitride ceramics materials workpiece with roughness 5nm Ra is obtained after CMP process with polyurethane polishing pad and CeO2 abrasive.

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Basic Study on Etching Selectivity of Plasma Chemical Vaporization Machining by Introducing Crystallographic Damage into Work Surface

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.625.550 ◽

2014 ◽

Vol 625 ◽

pp. 550-553 ◽

Cited By ~ 3

Author(s):

Yasuhisa Sano ◽

Toshiro Doi ◽

Syuhei Kurokawa ◽

Hideo Aida ◽

Osamu Ohnishi ◽

...

Keyword(s):

High Speed ◽

Substrate Surface ◽

Etching Rate ◽

Atmospheric Pressure Plasma ◽

Mean Free Path ◽

Machining Process ◽

Plasma Chemical ◽

Basic Study ◽

Cross Sectional ◽

Mechanical Machining

Plasma chemical vaporization machining (PCVM) is a high-speed plasma etching method using atmospheric-pressure plasma. Although it does not leave an affected layer on the processed surface because of the small ion energy owing to the small mean free path of gas molecules, it is not suitable for planarization because of its isotropic etching. Thus, a combination of PCVM and a mechanical machining process is proposed. The convex parts of a substrate surface are considered to be affected by mechanical machining and are removed preferentially by PCVM. In this report, it is investigated whether etching rate of the affected layer becomes larger or not. As a result, it was found that the etching rate increased in the first 100 nm depth of the mechanically polished substrate, which corresponds to the thickness of the heavily damaged layer observed by cross-sectional transmission electron microscopy.

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One-step Separation and Purification of Four Phenolic Acids from Stenoloma chusanum (L.) Ching by Medium-pressure Liquid Chromatography and High-speed Counter-current Chromatography

The Natural Products Journal ◽

10.2174/2210315508666181004115422 ◽

2019 ◽

Vol 9 (2) ◽

pp. 138-143

Author(s):

Tianyun Li ◽

Xiling Dai ◽

Yichen Li ◽

Guozheng Huang ◽

Jianguo Cao

Keyword(s):

Natural Products ◽

Liquid Chromatography ◽

Phenolic Acids ◽

High Speed ◽

High Efficiency ◽

Total Phenolic ◽

Medium Pressure ◽

Medium Pressure Liquid Chromatography ◽

One Step ◽

Counter Current

Background:Stenoloma chusanum (L.) Ching is a Chinese traditional medicinal fern with high total flavonoid and total phenolic content. Traditionally, phenolic compounds were separated by using column chromatography, which is relatively inefficient. </P><P> Objective: This study aims to use an efficient method to separate natural products from S. chusanum by Medium-Pressure Liquid Chromatography (MPLC) and High-Speed Counter-Current Chromatography (HSCCC).Methods:In the present research, firstly, a sample (2.5 g) from the dichloromethane extract of S. chusanum was separated by MPLC. Next, fraction P5 was purified by HSCCC with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water (HEMWat) at a volume ratio of 2:4:1:4 (v/v/v/v). </P><P> Result: Four phenolic acids were obtained and their structures were identified by means of NMR and ESI-mass analysis. They were identified as: 1) protocatechuic acid (34 mg, purity 90.1%), 2) syringic acid (66 mg, purity 99.0%), 3) p-hydroxybenzoic acid (5 mg, purity 91.2%) and 4) vanillic acid (6 mg, purity 99.3%).Conclusion:The combination of MPLC and HSCCC is a high-efficiency separation method for natural products. This is the first report with regard to the separation of four phenolic acids in one step by MPLC and HSCCC from S. chusanum (L.) Ching.

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On-chip trans-dimensional plasmonic router

Nanophotonics ◽

10.1515/nanoph-2020-0078 ◽

2020 ◽

Vol 9 (10) ◽

pp. 3357-3365 ◽

Cited By ~ 1

Author(s):

Shaohua Dong ◽

Qing Zhang ◽

Guangtao Cao ◽

Jincheng Ni ◽

Ting Shi ◽

...

Keyword(s):

High Speed ◽

High Efficiency ◽

Incident Angle ◽

Reciprocal Lattice ◽

Plasmonic Waveguide ◽

Optical Diffraction ◽

Local Dynamic ◽

Phase Gradient ◽

On Chip ◽

Plasmon Polaritons

AbstractPlasmons, as emerging optical diffraction-unlimited information carriers, promise the high-capacity, high-speed, and integrated photonic chips. The on-chip precise manipulations of plasmon in an arbitrary platform, whether two-dimensional (2D) or one-dimensional (1D), appears demanding but non-trivial. Here, we proposed a meta-wall, consisting of specifically designed meta-atoms, that allows the high-efficiency transformation of propagating plasmon polaritons from 2D platforms to 1D plasmonic waveguides, forming the trans-dimensional plasmonic routers. The mechanism to compensate the momentum transformation in the router can be traced via a local dynamic phase gradient of the meta-atom and reciprocal lattice vector. To demonstrate such a scheme, a directional router based on phase-gradient meta-wall is designed to couple 2D SPP to a 1D plasmonic waveguide, while a unidirectional router based on grating metawall is designed to route 2D SPP to the arbitrarily desired direction along the 1D plasmonic waveguide by changing the incident angle of 2D SPP. The on-chip routers of trans-dimensional SPP demonstrated here provide a flexible tool to manipulate propagation of surface plasmon polaritons (SPPs) and may pave the way for designing integrated plasmonic network and devices.

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Optimization of Air Gap Length and Capacitive Auxiliary Winding in Three-Phase Induction Motors Based on a Genetic Algorithm

Energies ◽

10.3390/en14154407 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4407

Author(s):

Mbika Muteba

Keyword(s):

Genetic Algorithm ◽

Design Process ◽

Power Factor ◽

High Speed ◽

High Efficiency ◽

Air Gap ◽

Element Analysis ◽

Three Phase ◽

High Torque ◽

Cage Induction Motor

There is a necessity to design a three-phase squirrel cage induction motor (SCIM) for high-speed applications with a larger air gap length in order to limit the distortion of air gap flux density, the thermal expansion of stator and rotor teeth, centrifugal forces, and the magnetic pull. To that effect, a larger air gap length lowers the power factor, efficiency, and torque density of a three-phase SCIM. This should inform motor design engineers to take special care during the design process of a three-phase SCIM by selecting an air gap length that will provide optimal performance. This paper presents an approach that would assist with the selection of an optimal air gap length (OAL) and optimal capacitive auxiliary stator winding (OCASW) configuration for a high torque per ampere (TPA) three-phase SCIM. A genetic algorithm (GA) assisted by finite element analysis (FEA) is used in the design process to determine the OAL and OCASW required to obtain a high torque per ampere without compromising the merit of achieving an excellent power factor and high efficiency for a three-phase SCIM. The performance of the optimized three-phase SCIM is compared to unoptimized machines. The results obtained from FEA are validated through experimental measurements. Owing to the penalty functions related to the value of objective and constraint functions introduced in the genetic algorithm model, both the FEA and experimental results provide evidence that an enhanced torque per ampere three-phase SCIM can be realized for a large OAL and OCASW with high efficiency and an excellent power factor in different working conditions.

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Research on Distance Transform and Neural Network Lidar Information Sampling Classification-Based Semantic Segmentation of 2D Indoor Room Maps

Sensors ◽

10.3390/s21041365 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1365

Author(s):

Tao Zheng ◽

Zhizhao Duan ◽

Jin Wang ◽

Guodong Lu ◽

Shengjie Li ◽

...

Keyword(s):

Neural Network ◽

High Speed ◽

High Performance ◽

High Efficiency ◽

Semantic Segmentation ◽

Raspberry Pi ◽

Distance Transform ◽

Testing Stage ◽

Sampling Points ◽

Information Sampling

Semantic segmentation of room maps is an essential issue in mobile robots’ execution of tasks. In this work, a new approach to obtain the semantic labels of 2D lidar room maps by combining distance transform watershed-based pre-segmentation and a skillfully designed neural network lidar information sampling classification is proposed. In order to label the room maps with high efficiency, high precision and high speed, we have designed a low-power and high-performance method, which can be deployed on low computing power Raspberry Pi devices. In the training stage, a lidar is simulated to collect the lidar detection line maps of each point in the manually labelled map, and then we use these line maps and the corresponding labels to train the designed neural network. In the testing stage, the new map is first pre-segmented into simple cells with the distance transformation watershed method, then we classify the lidar detection line maps with the trained neural network. The optimized areas of sparse sampling points are proposed by using the result of distance transform generated in the pre-segmentation process to prevent the sampling points selected in the boundary regions from influencing the results of semantic labeling. A prototype mobile robot was developed to verify the proposed method, the feasibility, validity, robustness and high efficiency were verified by a series of tests. The proposed method achieved higher scores in its recall, precision. Specifically, the mean recall is 0.965, and mean precision is 0.943.

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