Kita-ku, Japan
Kita-ku, Japan

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Yamamoto S.,Sankei Giken Kogyo Co. | Kawana A.,Japan Coating Center Co. | Masuda C.,Waseda University
Surface and Coatings Technology | Year: 2013

Two types of diamond-like carbon (DLC) were evaluated for their tribological behavior in terms of the tribometer input energy. The DLC samples were prepared from methane (denoted DLC[CH4]) or benzene (denoted DLC[C6H6]) as a gas source on tungsten-carbide (WC) substrates by radio-frequency plasma chemical vapor deposition (rf-PCVD). The hydrogen contents of the DLCs were measured by Elastic Recoil Detection Analysis (ERDA). The DLC structures were investigated by Raman spectrometry and X-ray photoelectron spectroscopy (XPS). The basic mechanical properties, such as the hardness and the Young's modulus, were obtained by a nano-indenter. The DLC films against alumina were tribo-tested by a ball-on-disk. The input energy was calculated using the applied load, the friction coefficient, and the sliding distance in each tribo-test. The wear behavior of the DLC[CH4] sample was better than that of the DLC[C6H6], even though the hardness of DLC[CH4] was lower than that of DLC[C6H6]. The wear loss of DLC[CH4] and DLC[C6H6] was evaluated by the input energy, and the wear resistance difference of the DLCs was characterized in terms of the input energy. © 2013 Elsevier B.V.


Yamamoto S.,Sankei Giken Kogyo Co. | Kawana A.,Japan Coating Center Co. | Masuda C.,Waseda University
Tribology - Materials, Surfaces and Interfaces | Year: 2013

The tribological behaviour of stainless steel (SUS 440C) relative to that of diamond-like carbon (DLC) was investigated in terms of tribometer input energy. The DLC was prepared on tungsten carbide (WC) substrates using radio frequency plasma chemical vapour deposition with benzene (C6H6) as a gas source. The stainless steel ball, as the counterpart, was tribotested. The input energy was calculated using the applied load, friction coefficient and sliding distance obtained from each tribotest. The wear loss of the ball increased as the sliding distance increased, whereas wear loss of the DLC was not directly observed. During evaluation of the input energy, the wear rate of the stainless steel ball decreased as the input energy increased. We propose a method for evaluating tribological properties using the input energy and discuss the wear behaviour of the stainless steel based on the input energy. © 2013 W. S. Maney & Son Ltd.


Yamamoto S.,Sankei Giken Kogyo Co. | Okuaki T.,Sankei Giken Kogyo Co. | Egashira M.,Japan National Institute of Materials Science | Kondoh K.,Osaka University | Masuda C.,Waseda University
Tribology - Materials, Surfaces and Interfaces | Year: 2015

Temperature rise in carbon steel (SUJ2-ASTM E52100) and stainless steel (SUS440C-ASTM 440C) balls sliding against diamond like carbon was evaluated using thermal simulation. On the premise that most of the friction energy was consumed as friction heat, the temperature distribution in the steel balls was simulated by ANSYS thermal conduction analysis using the friction energy measured by the ball on disc test. The interior temperatures of the steel balls were also monitored by a thermocouple during the tribotest. The simulation data, calibrated by the heat partition rate based on the Peclet number, were compared to the experiment data, and good accordance of both data was demonstrated. © 2015 W. S. Maney & Son Ltd.


Yamamoto S.,Sankei Giken Kogyo Co. | Egashira M.,Japan National Institute of Materials Science | Kondoh K.,Osaka University | Masuda C.,Waseda University
Tribology - Materials, Surfaces and Interfaces | Year: 2015

In this work, we evaluated the different energy consumption rates associated with the total frictional energy for a ball sliding on a flat surface. The energy generated by the sliding two bodies in contact is dissipated into the materials in various forms. The wear consumption energy for a steel ball against a diamond-like carbon surface was evaluated by the wear coefficient of the wear volume–energy input equation. The strain energy generated in the steel ball as a result of being made to slide under a certain load was calculated using the Hertzian theory. The chemical reaction energy was estimated based on iron oxidation. Finally, the frictional energy dissipated as heat was obtained by subtracting the wear and the strain energies from the total frictional energy. © 2015 Institute of Materials, Minerals and Mining and W. S. Maney & Son Ltd.


A modified Archard–Holms type of wear volume equation was reconsidered in terms of its energetic aspects. Both the wear volume equation and the friction coefficient are treated in terms of frictional energy. A theoretical approach to the wear volume-frictional energy equation proposes that the wear coefficient consists of the wear particle size and surface energy as well as the ratio of the wear energy to the frictional energy. The value of the wear coefficient of nitrogenated diamond-like carbon was estimated using the measured hardness, wear particle size and surface energy and compared to the wear coefficient obtained by the wear volume-frictional energy test on the ball-on-disk method. The wear volume equation, using the Young׳s modulus instead of the hardness, was introduced based on fracture theory, and the wear volume equation is shown to be equivalent to the conventional wear volume equation for nitrogenated diamond-like carbon. © 2016 Elsevier B.V.


Patent
Sankei Giken Kogyo Co. | Date: 2014-02-18

A muffler has a first flared part provided at an opening end portion of an upper half body of a muffler shell. A flange is provided at a tip of a peripheral wall extending substantially vertically and belonging to the first flared part. The flange is bent to project outwardly. A second flared part is provided at the opening end portion of the lower half body of the shell. A peripheral wall of the second flared part is press fitted inside the peripheral wall of the first flared part to fit into the peripheral wall so as to extend substantially along the peripheral wall. A part of the peripheral wall of the first flared part and a part of the peripheral wall of the second flared part that fit into each other are laser welded along their entire peripheries, thereby forming a welded part.


An object of the present invention is to provide an electromagnetic wave penetrative metal film having high mass productivity and an extremely low attenuation rate in the electromagnetic wave penetrated through, a manufacturing method of the electromagnetic wave penetrative metal film, and a radome for a vehicle-mounted radar devices using the electromagnetic wave penetrative metal film. To achieve the object, the present invention provides an electromagnetic wave penetrative metal film composed of more than 10000 of fine metal film pieces per unit area (1 mm^(2)) provided on a surface of a substrate through an electroless plating step, wherein fine metal film pieces adjacent to each other are electrically isolated, a manufacturing method of the electromagnetic wave penetrative metal films, and a radome for a vehicle-mounted radar devices using the electromagnetic wave penetrative metal films.


Patent
Sankei Giken Kogyo Co. | Date: 2013-09-06

A method of manufacturing a bright surface product comprises a step of performing electroless plating to form a first metal film on a base coat layer formed on a substrate, a step of performing electrolytic plating to form a second metal film thereon so that the bonding strength between each film of a multi-layered metal film comprising the first metal film and the second film is higher than the bonding strength between the base coat layer and the first metal layer, a step of integrally and discontinuously segmentalizing the multi-layered metal film with cracks to form an island-like metal film comprising a collection of fine multi-layered metal regions with island-like structures; and a step of forming a translucent top coat layer to cover the fine multi-layered metal regions of the island-like metal film and enter into the cracks to make contact with the base coat layer.


Patent
Sankei Giken Kogyo Co. | Date: 2015-07-22

Provided is a method of manufacturing a bright surface product having good surface brightness and excellent rust and detachment resistance which can be produced in a large scale at low cost. The method comprises: a step of performing electroless plating to form a first metal film 23 on a base coat layer 22 formed on a substrate 21; a step of performing electrolytic plating to form a second metal film 24 thereon so that the bonding strength between each film of a multi-layered metal film comprising the first metal film 23 and the second film 24 is higher than the bonding strength between the base coat layer 22 and the first metal layer 23; a step of integrally and discontinuously segmentalizing the multi-layered metal film with cracks 26 by utilizing the difference in internal stress between the substrate 21 and the multi-layered metal film to form an island-like metal film comprising a collection of fine multi-layered metal regions 25 with island-like structures and having an appearance of an integrated bright surface; and a step of forming a translucent top coat layer to cover the fine multi-layered metal regions 25 of the island-like metal film and enter into the cracks 26 to make contact with the base coat layer 22.


An object of the present invention is to provide an electromagnetic wave penetrative metal film having high mass productivity and an extremely low attenuation rate in the electromagnetic wave penetrated through, a manufacturing method of the electromagnetic wave penetrative metal film, and a radome for a vehicle-mounted radar devices using the electromagnetic wave penetrative metal film. To achieve the object, the present invention provides an electromagnetic wave penetrative metal film composed of more than 10000 of fine metal film pieces per unit area (1 mm^(2)) provided on a surface of a substrate through an electroless plating step, wherein fine metal film pieces adjacent to each other are electrically isolated, a manufacturing method of the electromagnetic wave penetrative metal film, and a radome for a vehicle-mounted radar devices using the electromagnetic wave penetrative metal film.

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