A Study of Developing Composite Material of Penetrated Diamond Particles Into Metal Plate

2009 ◽  
Author(s):  
Keijiro Nishi ◽  
Shigeru Tanaka ◽  
Shigeru Itoh
Keyword(s):  
Thermal Conductivity ◽  
Shock Wave ◽  
Composite Material ◽  
High Speed ◽  
High Hardness ◽  
Optical Microscope ◽  
Metal Plate ◽  
Underwater Shock Wave ◽  
Diamond Particles ◽  
Underwater Shock

An explosive welding technique which uses underwater shock wave to weld thin aluminum plate has been studied and the technical advantages were reported. In this research, we propose a method to produce a composite material using an underwater shock wave generated by detonation of explosive. In the production process, a metal plate (flyer plate) accelerates to a high speed by the underwater shock wave, and collided with diamond particles and penetrated the metal plate. Diamonds were used as the particles and aluminum plates (A1050) as the flyer plates. Diamond has high hardness and excellent thermal conductivity, therefore diamond should provide improvement in the thermal conductivity of the composite material. From recovered sample, the multilayer joined surface including diamond particles was observed using an optical microscope. The production of the pipe of composite materials was attempted using this technique as the application. Details of the experimental methods and results are reported in this paper.

Deformation Mechanism of Metal Plate on Explosive Forming

2005 ◽  
Author(s):  
Hirofumi Iyama ◽  
Takeshi Hinata ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
High Speed ◽  
Underwater Explosion ◽  
Metal Plate ◽  
Sufficient Accuracy ◽  
Underwater Shock Wave ◽  
Underwater Shock ◽  
Explosive Forming ◽  
Forming Methods

The explosive forming is one of the forming methods of a metal plate performed since the 1950s. This method is different from usual static press forming. The metal plate is accelerated by underwater shock wave, which is generated by underwater explosion of an explosive. In order to deform a metal plate in predetermined form with sufficient accuracy using this forming method, it is important to grasp the mechanism. At first, it is necessary to grasp that an underwater shock wave spreads and it collides with the metal plate. And it is also necessary to show clearly what deformation of the metal plate with high-speed. Then, we investigated about the mechanism in the numerical simulation. In this research, LS-DYNA, which is the software for shock analysis was used. Moreover, the experiment was also conducted in order to confirm whether this numerical simulation is exact.

Research on the Powder Consolidation by Using Shock Compaction Method

2010 ◽  
Author(s):  
Keijiro Nishi ◽  
Makoto Ide ◽  
Nozomi Terasawa ◽  
Seiichi Irie ◽  
Shigeru Itoh
Keyword(s):  
Thermal Conductivity ◽  
Shock Wave ◽  
Composite Material ◽  
Particle Surface ◽  
Copper Matrix ◽  
Underwater Shock Wave ◽  
Powder Consolidation ◽  
Shock Compaction ◽  
Underwater Shock ◽  
Diamond Powders

Shock compaction of powder by using an underwater shock wave is studied and the technical advantages are reported. In this research, we propose a technique for shock compaction of copper/diamond powders by using an underwater shock wave generated by the detonation of explosive. This process produces a composite material in which the particles are strongly bonded due to melting caused by strong deformation and rapid solidification at the particle surface. The improvement of the thermal conductivity of the composite material collected is expected, because the diamond has a high thermal conductivity. Good compacts of composite materials in which diamond particles were dispersed in the copper matrix were obtained in this experiment, and their microstructures and thermal properties were examined. Moreover, pressure measurements and numerical calculations were performed to assess the effect of the pressuring condition in the explosive container.

New Technique for “Cullet” Generation of Glass Bottles by Using Underwater Shockwave

2006 ◽  
Vol 326-328 ◽  
pp. 1551-1554
Author(s):  
Hidetoshi Sakamoto ◽  
Shinjiro Kawabe ◽  
Kazuo Satoh ◽  
Masahiro Himeno ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Fracture Process ◽  
Image Converter ◽  
Glass Bottle ◽  
Underwater Shock Wave ◽  
Application Technique ◽  
System A ◽  
Underwater Shock ◽  
Glass Bottles

As the application technique for glass bottle’s recycling system, a new “Cullet” generation method by using underwater shock wave was proposed. This small fragmentation technique of glass bottles has a lot of excellent advantages such as the simplification of process by simultaneous cleaning and crushing operation, the high collect rate of “Cullet” and so on. In this study, the relation between of the explosive conditions and “Cullet” sizes were clarified and the high speed fracture process of glass bottle was observed by framing photograph of high speed image converter.

Exfoliation of Marine Organisms Technology by Using Underwater Shock Wave

2005 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Hirofumi Iyama ◽  
Ayumi Takemoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Marine Organisms ◽  
High Speed Camera ◽  
Sluice Gate ◽  
Underwater Shock Wave ◽  
Manual Operation ◽  
Fluid Resistance ◽  
Personnel Expenses ◽  
Underwater Shock

Adhesion problem of marine organisms often becomes a problem, in the case of ship, marine floating construction and sluice gate of power plant. These make fluid resistance of a hull increase, cause a buoyancy fall, or cause reducing coolant etc. Although these are chiefly removed by manual operation now, immense expense and immense labors, such as personnel expenses and time and effort, are needed. We tried application of an underwater shock wave, in order to solve these problems. Interference of a shock wave and the mechanism of marine organisms exfoliation were explored using the explosive and PMMA plate, which imitated a marine organisms adhesion. The process of exfoliation of organisms from PMMA plate was observed by using of the high-speed camera.

Study on the Effects of Shock Wave Propagation on Explosive Forming

2013 ◽  
Vol 767 ◽  
pp. 132-137
Author(s):  
Hirofumi Iyama ◽  
Yoshikazu Higa ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Pressure Vessel ◽  
Pressure Pulse ◽  
Metal Plate ◽  
Water Medium ◽  
Underwater Shock Wave ◽  
Pressure Transmission ◽  
Underwater Shock ◽  
Explosive Forming ◽  
Primary Shock

Explosive forming is one of the unconventional techniques, in which, most commonly, the water is used as the pressure transmission medium. The explosive is set at the top of the pressure vessel filled with water, and is detonated by an electric detonator. The underwater shock wave propagates through the water medium and impinges on the metal plate, which in turn, deforms. There is another pressure pulse acting on the metal plate as the secondary by product of the expansion of the gas generated by detonation of explosive. The secondary pressure pulse duration is longer and the peak pressure is lower than the primary shock pressure. However, the intensity of these pressure pulse is based also on the conditions of a pressure vessel. In order to understand the effects of the configuration of the pressure vessel on the deformation of a metal plate, numerical simulation was performed. This paper reports those results.

Basic Study on the Crushing of Frozen Soil by Shock Loading

2007 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Hironori Maehara ◽  
Masahiko Otsuka ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Frozen Soil ◽  
High Speed Camera ◽  
Underwater Shock Wave ◽  
Basic Study ◽  
Underwater Shock ◽  
A New Technique

The aim of study is to confirm a new technique that can crush the frozen soil and/or ice block using underwater shock wave generated by the underwater explosion of explosive. This technique can lead to the earlier sowing, which can have the larger harvest because the duration of sunshine increases. Especially, in Hokkaido prefecture, Japan, if the sowing is carried out in April, we can expect to have 150% of harvest in the ordinary season. This technique is effective against the cold regions. For example, Korea, China, Mongolia, Russia, Norway, and Sweden, etc. At first, we carried out experiments usung a detonating fuse and ice block. The process of ice breaking was observed by means of a high-speed camera. In order to check about that influence we tried to give an actual frozen soil a shock wave.

Influence of Pressure Vessel Shape on Explosive Forming

2018 ◽  
Author(s):  
Hirofumi Iyama ◽  
Masatoshi Nishi ◽  
Yoshikazu Higa
Keyword(s):  
Shock Wave ◽  
Pressure Vessel ◽  
Underwater Explosion ◽  
Metal Plate ◽  
Reflected Shock Wave ◽  
Underwater Shock Wave ◽  
Reflected Shock ◽  
Final Deformation ◽  
Underwater Shock ◽  
Explosive Forming

The explosive forming is a characteristic forming method. This technique is a metal forming using an underwater shock wave. The underwater shock wave is generated by underwater explosion of the explosive. The metal plate is formed with involving the high strain rate on this technique. In generally, the pressure vessel is used in this method due to the effective utilization of the explosion energy. The underwater shock wave is propagated in water and reflected on inside wall of the pressure vessel. This reflected shock wave is affected on the deformation shape of a metal plate. Therefore, the inside shape of pressure vessel is often changed. In other words, the shape of pressure vessel is changed, the shock pressure distribution on the metal plate and it is possible that final deformation shape of the metal plate is changed. Some numerical simulations and experiments have been carried out to clear the influence of the inside shape of pressure vessel in the explosive forming. This paper is included the results and discussions on the numerical simulation and experiment used those conditions.

Investigation of a converging underwater shock wave using high-speed photography

1995 ◽  
Author(s):  
Shigeru Itoh ◽  
S. Kubota ◽  
Shirou Nagano ◽  
I. Morita ◽  
A. Chiba ◽  
...  
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
High Speed Photography ◽  
Underwater Shock Wave ◽  
Underwater Shock

A Deburring Process Performed by Underwater Shock Wave

2011 ◽  
Vol 673 ◽  
pp. 271-274 ◽  
Author(s):  
Kazumasa Shiramoto ◽  
Junki Shimizu ◽  
Akiyoshi Kobayashi ◽  
Masahiro Fujita
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Present Report ◽  
Shock Pressure ◽  
Normal Operation ◽  
Underwater Shock Wave ◽  
Water Flows ◽  
Underwater Shock ◽  
Machining Operations ◽  
Equipment Performance

A burr is most commonly created after machining operations, such as drilling. Drilling burrs, for example, are common when drilling almost any material. When burrs are broken during the operation of a machine including the parts with the created burrs, the broken piece is in fear of disturbing normal operation or damaging the parts of the machine, so that the sufficient deburring is requested because it can affect equipment performance, reliability, and durability. Several deburring method have been developed up to date. In the present report, we proposed a deburring method by means of applying underwater shock wave. The method is as follows: after all entrance of holes is closed with seal tape, the equipment is submerged, so that all passages for running fluid are filled with air. The explosive is set under water near the entrance of the main hole. As soon as the explosive is detonated, the underwater shock wave generated at the detonation point arrives at the entrance of the hole and breaks through the tape. The water flows into the hole with a high speed. The burr is broken by water hummer action of high speed. In the present investigation, the experiments of deburring are performed under some setting conditions of explosive. It is found by experimental results, that the burr is sufficiently removed with the newly proposed method. When the shock pressure is sufficiently high at the entrance of hole, the burr is broken surface is smooth as polished one. When the shock pressure is not sufficiently high, the broken surface of the burr is notched.

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