scholarly journals Electrical contact resistance in graphite–graphene contacts from ab initio methods

2018 ◽  
Vol 30 (32) ◽  
pp. 325302 ◽  
Author(s):  
Ferran Jovell ◽  
Xavier Cartoixà
Keyword(s):  
Contact Resistance ◽  
Ab Initio ◽  
Electrical Contact ◽  
Ab Initio Methods ◽  
Electrical Contact Resistance

scholarly journals The Wear Process During the “Running-In” of Steel in Lubricated Sliding

1987 ◽  
Vol 109 (4) ◽  
pp. 587-591 ◽  
Author(s):  
M. Suzuki ◽  
K. C. Ludema
Keyword(s):  
Contact Resistance ◽  
Surface Film ◽  
Electrical Contact ◽  
Mineral Oil ◽  
Entrance Region ◽  
Engine Oil ◽  
Small Range ◽  
Electrical Contact Resistance ◽  
Metallic Contact ◽  
Wear Process

Steel cylinders were slid against flat steel disks, using a liquid lubricant, in order to study the progression of events associated with “running-in.” It was found that, when using mineral oil, the electrical contact resistance varied over a small range of high values indicating no metallic contact, whereas with engine oil a high resistance with an intermittent negligible contact resistance was found. A surface film forms from the additives in the engine oil which produces lower wear, slightly higher friction, a retarded running-in, and a rougher surface finish in the direction of sliding than does the mineral oil. A film which is composed only of Fe3O4 is formed when mineral oil is used. In addition, the mineral oil lubricated surfaces develop a conforming waviness across the sliding tracks. The oxide must have enhanced this surface conformity since it was not seen in the surfaces lubricated with engine oil. The role of the oxide may be further seen in experiments in which wear debris that accumulated in the entrance region of specimen contact was removed at frequent intervals. Little conforming waviness was seen in the latter case, suggesting that oxide which gathered in the entrance region abraded grooves in the steel surfaces. After the oxides were dislodged the friction increased and the contact resistance decreased for a time, indicating that the oxide acted like a solid lubricant.

Simultaneous Electrical and Thermal Modeling of a Contact-Type RF MEMS Switch

2003 ◽  
Author(s):  
Brian Jensen ◽  
Zhongde Wang ◽  
Kazuhiro Saitou ◽  
John L. Volakis ◽  
Katsuo Kurabayashi
Keyword(s):  
Contact Resistance ◽  
Direct Contact ◽  
Rf Mems ◽  
Bulk Material ◽  
Thermal Contact ◽  
Electrical Contact ◽  
Maximum Temperature ◽  
Electrical Contact Resistance ◽  
Rf Mems Switch ◽  
Mems Switch

Improving the power handling capability of direct contact RF MEMS switches requires a knowledge of conditions at the contact. This paper models the temperature rise in a direct contact RF MEMS switch, including the effects of electrical and thermal contact resistance. The maximum temperature in the beam is found to depend strongly on the power dissipation at the contact, with almost no contribution from dissipation due to currents in the rest of the switch. Moreover, the maximum temperature is found to exceed the limit for metal softening for a significant range of values of thermal and electrical contact resistance. Since local contact asperity temperature can be hundreds of degrees higher than the bulk material temperature modeled here, these results underscore the importance of understanding and controlling thermal and electrical contact resistance in the switch.

Failure mechanism in fiber-shaped electrodes for lithium-ion batteries

2015 ◽  
Vol 3 (20) ◽  
pp. 10942-10948 ◽  
Author(s):  
Wei Weng ◽  
Qingqing Wu ◽  
Qian Sun ◽  
Xin Fang ◽  
Guozhen Guan ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Failure Mechanism ◽  
Electrical Contact ◽  
Active Material ◽  
Lithium Ion ◽  
Current Collector ◽  
Conductive Network ◽  
Electrical Contact Resistance ◽  
Loss Of Contact ◽  
First Time

Failure mechanism is investigated for the first time in a Si-based fiber-shaped electrode. The interphase electrical contact resistance indicates the dominant failure mechanism, which is the loss of contact between the current collector/conductive network and the active material. The decreasing contact resistance denotes the loose interphase contact and a decreasing capacity.

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