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An enhanced Cu-based friction material was prepared by the powder metallurgy techniques and proposed for use in the dry clutch system. The friction characteristics and wear rate of this friction material sliding against 65Mn steel are obtained using Universal Material Tester-5. The friction pairs were subjected to two operating variables, which are sliding speed and temperature. The effect of these variables during the engagement process of the friction pairs is investigated. Knowing the normal applied force and dimension of the clutch disc, the dynamic friction coefficient was translated to friction torque capacity with time. It was found that instability can be excited at low operational conditions when the resulting friction coefficient is high. At 25 ℃, the dynamic friction torque oscillates with time likewise at 400 ℃. Generally, a more stable friction torque is obtained when the sliding speed is varied compared to varying the temperatures. Moreover, the influence of the operating temperatures and sliding speeds on thermal buckling and thermoelastic instability of the friction disc is the second consideration in this work. The onset of thermoelastic instability occurs when the sliding speed exceeded 200 r/min and the results for the growth rate of hot spots were found to agree well with the critical speed of the system. Also, thermal buckling was highly dependent on the temperature difference between the inner and outer radius of the friction disc.
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Surface property study of additively manufactured Inconel 625 at room temperature and 510 °C
Various mechanical systems are subjected to inherent oscillatory motions often paired with extreme, high-temperature environments resulting in fretting wear. In this work, the fretting wear resistance of additively manufactured Inconel 625 was studied at room and elevated temperatures. In-situ temperature-controlled nanoindentation was employed to further elucidate mechanical property evolution as a function of temperature. The results showed a 30% decrease in near-surface mean hardness at 510 °C compared to room temperature. However, the material exhibited significantly lower wear and coefficient of friction values at high temperatures, attributed to the formation of a compacted, intermediate oxide layer preventing excessive friction and wear.
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- Award ID(s):
- 2029059
- PAR ID:
- 10288982
- Date Published:
- Journal Name:
- Manufacturing letters
- Volume:
- 26
- ISSN:
- 2213-8463
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/doi.org/10.1016/j.mfglet.2020.10.001
