- 著者
- Kouki Ozawa Alan Hase
- 雑誌
- ITC Fukuoka 2023
- 巻号頁・発行日
- 2023-05-26
- 著者
- Alan Hase
- 雑誌
- ITC Fukuoka 2023
- 巻号頁・発行日
- 2023-05-26
- 著者
- Alan Hase
- 出版者
- Japanese Society of Tribologists
- 雑誌
- Tribology Online (ISSN:18812198)
- 巻号頁・発行日
- vol.18, no.5, pp.202-216, 2023-08-31 (Released:2023-08-31)
- 参考文献数
- 19
Due to the continuing decrease in the proportion of young people in the population, it is likely to become more difficult to secure the researchers who will lead the next generation. To overcome this problem, it will be necessary to arouse the interest of children and young people in science and engineering. Tribology is the study and application of the principles of friction, lubrication, and wear, and is an interdisciplinary discipline spanning many fields; consequently, the study of tribology can encourage interdisciplinary learning. Furthermore, tribology is an important discipline of itself because it has a direct relationship to issues of energy and the environment. Teaching tribology to young people and helping them to understand it could arouse their interest in a variety of aspects of science and engineering. The key is how to introduce the various academic aspects of tribology, a complex and mysterious discipline, in an engaging manner. The author has energetically striven to promote introductory education to enlighten the next generation about tribology by using a novel educational method that incorporates a problem-solving game. This paper describes the effectiveness of this educational method, the content of the developed teaching materials, and the results in educational practice.
- 著者
- Kouki Imai Alan Hase
- 出版者
- Japanese Society of Tribologists
- 雑誌
- Tribology Online (ISSN:18812198)
- 巻号頁・発行日
- vol.17, no.2, pp.86-96, 2022-05-15 (Released:2022-05-15)
- 参考文献数
- 15
- 被引用文献数
- 2
The purpose of this study is to identify tribological phenomena that occur on a machined surface under grinding, using acoustic emission (AE) sensing. The study investigated features exhibited by AE signals due to a change of state of the machined surface during the finish grinding of glass materials. An AE sensor was attached to a glass test piece, and the AE signals generated by using a grinding wheel rotating at high speed were measured. It was found that differences in the grain size of the grinding wheel and the hardness of the test piece changed the amplitude of the AE signal, and that there was a correlation between the amount removed by grinding and the AE mean value. In addition, a frequency analysis of the AE signal waveforms revealed that the AE frequency components generated during friction and during grinding differ. It was also found that a change in grinding ability of the grinding wheel, due to it wearing flat or to abrasive grains falling away, can be established from the change in AE mean value and the peak position in the AE frequency spectrum.
- 著者
- Miho Morita Shodai Tachiyama Ko Onodera Alan Hase
- 出版者
- Japanese Society of Tribologists
- 雑誌
- Tribology Online (ISSN:18812198)
- 巻号頁・発行日
- vol.17, no.2, pp.78-85, 2022-04-30 (Released:2022-04-30)
- 参考文献数
- 10
- 被引用文献数
- 2
Sulfur and phosphorus additives are used in lubricants as extreme-pressure and antiwear agents, which are typically used together to ensure reliability over a wide range of lubrication conditions. However, the working mechanism of the combined additive system has not been clearly defined due to difficulties obtaining information on the material surface where these additives work. This is because this surface is constantly being worn during testing. Therefore, in situ analysis applying an acoustic emission (AE) technique was proposed. AEs are elastic stress waves generated during the deformation and fracture of solids, which can be measured in real-time, providing information with respect to the magnitudes and types of damage. In this paper, an application of the AE helps to clarify how each additive acts on the surface in real-time. The working mechanism to understand improved reliability using both sulfur and phosphorous additives was investigated by the AE technique, along with conventional surface analysis methods. It is concluded that wear reducing properties were improved by the reaction of sulfur additives to remove the protruded parts, followed by the reaction of phosphorous additives to form a protective antiwear film.
- 著者
- Alan Hase Masaki Wada Hiroshi Mishina
- 出版者
- (社)日本トライボロジー学会
- 雑誌
- Tribology Online (ISSN:18812198)
- 巻号頁・発行日
- vol.3, no.5, pp.298-303, 2008-10-15 (Released:2008-10-15)
- 参考文献数
- 22
- 被引用文献数
- 6 16
The relationship between acoustic emission (AE) signals and wear phenomena in severe-mild wear transition is discussed on the basis of the results of observations of wear particles and worn surfaces of steel. Each wear mode, severe wear or mild wear, is reproduced for a different sliding velocity. The influence of relative humidity on mild wear is examined. We found a reduction in the true area of contact and the size of wear particles decreases the AE signal level in severe-mild wear transition. In the mild wear mode, an increase in the number of transfer particles lying between the sliding surfaces decreases the AE signal level. Further, a linear relationship is observed between the AE mean value and the specific wear rate, regardless of the wear mode. This is because the AE signals generated by the formation and removal of transfer particles mainly originate under conditions of repeated dry rubbing.