Atsushi Korenaga
National Institute of Advanced Industrial Science and Technology
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Publication
Featured researches published by Atsushi Korenaga.
Japanese Journal of Applied Physics | 2004
Koji Miyake; Satoru Fujisawa; Atsushi Korenaga; Takao Ishida; Shinya Sasaki
We used atomic force microscopy (AFM) for the indentation test evaluating the indentation hardness of materials in the nanometer range. BK7, fused silica, and single-crystal silicon were used as test sample materials. The data analysis processes used to determine the contact area were important in evaluating the indentation hardness of the materials. The direct measurement of the size of the residual hardness impression was useful in evaluating the contact area even in the nanometer region. The results led us to conclude that AFM indentation using a sharp indenter is a powerful method for estimating the indentation hardness in the nanometer range.
Journal of Tribology-transactions of The Asme | 1999
Takeo Yoshioka; Atsushi Korenaga; Hiroki Mano; Takashi Yamamoto
We have developed a new method for measuring time intervals of Acoustic Emission (AE) generation for diagnosis of a radial rolling bearing. The method makes the AE signal itself a trigger of the oscillation of the clock pulse and measures the time interval of AE generation by integration of the clock pulses. The measurement device consists of the threshold, clock, time interval measurement and memory circuit, and was applied to rolling contact fatigue experiments. It was confirmed by the experiments that the measured time intervals of AE generation on the inner raceway or the ball agreed with the value calculated based on the kinetics of the rolling bearing. Moreover, we could identify the elements in which a fatigue crack was propagating by the method before the spalling appeared. The identified elements agreed with the failed elements.
Journal of Physics D | 2010
Koji Miyake; Miki Nakano; Atsushi Korenaga; Hiroki Mano; Yasuo Ando
The tribological properties of nanostripe surface structures were investigated using a pin-on-plate tribometer in order to propose a design concept for improving the tribological properties. The authors used four kinds of nanostripe structures consisting of different combinations of materials (Fe–Au, C–SiC, Al–Al2O3 and Al–Pt) fabricated by a process they had previously proposed. The frictional properties of the nanostripe structures depended on the materials that constituted the nanostripes. When the sliding direction in friction tests was parallel to the microgrooves, nanostripe structures remained on all surfaces even after friction tests. Based on the friction test results, the authors considered a design concept for nanostripe structures in tribological applications.
Journal of Tribology-transactions of The Asme | 1999
Takao Yoshimura; Kyosuke Ono; Kô Inagaki; Hideki Kotsuka; Atsushi Korenaga
We investigated the lubricating characteristics between a vane and piston lubricated with an oil-refrigerant mixture. Theoretical analyses were performed using mixed elastohydrodynamic lubrication analysis theory, taking metallic contacts into account. Lubricating conditions were evaluated by comparing the theoretical results of piston dynamics based on actual surface roughness distributions measured by SEM, with the experimental results measured under practical operation. We conclude that (1) lubricating conditions between the vane and piston can be assumed to be within the mixed lubricating zone, in which the coefficient of friction changes from 0.04 to 0.08, and the contact force is almost equally supported by oil film and metallic contact; (2) the coefficient of friction decreases as the contact force increases because the ratio of pressure rise of the oil film to the decrease in clearance is much greater than that for metallic contact pressure; and (3) in mixed EHL analysis, it is important not only to measure the actual surface roughness but also to select the appropriate contact model.
Advanced Materials Research | 2012
Seisuke Kano; Atsushi Korenaga
The mechanical behavior of the surface of metals is strongly affected by surface fracture occurring in the process of mechanical shearing, especially in shaper-type cutting performed for the application of ultra-fine optical manufacturing and several types of nanotechnology. This discussion aims to elucidate the tribological behavior of pure Cu. In ultra-precise cutting, the physics of crystallographic interfaces is extremely important for controlling surface fracture behavior. In this study, surface fracture behavior was evaluated using single crystal copper cut in two different directions (along the (100) and (111) planes). For V-shaped groove cutting, the flat copper surface was cut with a diamond-tip cutting tool (with a V angle of 90°, a rake angle of 0°, and an escape angle of 7°) at a machining speed of 4-4000 mm/min and a cutting depth of 0.2-10 m. The machined surface was observed with a laser scanning microscope and compared with two groove shapes, in which the cutting grooves in the two cutting directions were found to be different. This result was considered to depend on whether the cutting tool moved along the slip planes {111}, which are oriented in the direction. In the case of shallow cutting (under 1 m), the springback behavior became apparent for cutting in the slip plane direction, where the mechanism of this behavior would be associated with the interface between slip-plane fractures created by the cutting tool.
Tribology Letters | 2007
Miki Nakano; Atsuko Korenaga; Atsushi Korenaga; Koji Miyake; Takashi Murakami; Yasuhisa Ando; Hatsuhiko Usami; Shinya Sasaki
Tribology Letters | 2009
Miki Nakano; Koji Miyake; Atsushi Korenaga; Shinya Sasaki; Yasuhisa Ando
Intermetallics | 2007
Takashi Murakami; K. Kaneda; Miki Nakano; Hiroki Mano; Atsushi Korenaga; Shinya Sasaki
Archive | 1997
Takeo Yoshioka; Atsushi Korenaga
Tribology International | 2008
Takashi Murakami; K. Kaneda; Miki Nakano; Atsushi Korenaga; Hiroki Mano; Shinya Sasaki
Collaboration
Dive into the Atsushi Korenaga's collaboration.
National Institute of Advanced Industrial Science and Technology
View shared research outputsNational Institute of Advanced Industrial Science and Technology
View shared research outputsNational Institute of Advanced Industrial Science and Technology
View shared research outputsNational Institute of Advanced Industrial Science and Technology
View shared research outputsNational Institute of Advanced Industrial Science and Technology
View shared research outputsNational Institute of Advanced Industrial Science and Technology
View shared research outputsNational Institute of Advanced Industrial Science and Technology
View shared research outputs