• Title/Summary/Keyword: sliding interface temperature

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Temperature Rise Analysis of Sliding Contact Surfaces in Lubrication Considering Elastic Deformation (탄성변형을 고려한 윤활 상태에서 거친 표면의 미끄럼 접촉온도 해석)

  • Cho Yong-Joo;Kim Byoung-Sun;Lee Sang-Don
    • Tribology and Lubricants
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    • v.22 no.3
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    • pp.137-143
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    • 2006
  • The sliding contact interface of machine components such as bearings, gears frequently operates in lubrication at the inception of sliding failure under high loads, speed and slip. The surface temperature at the interface of bodies in a sliding contact is one of the most important factors influencing the behavior of machine components. Most surface failure in sliding contact region result from frictional heat generation. However, it is difficult to measure temperature rise experimentally. So the calculation of the surface temperature at a sliding contact interface has long been an interesting and important subject for tribologist. The surface temperature rise is related in contact pressure, sliding speed, material properties and lubrication thickness. Though roughness, load, ect all of the condition, are same, film thickness varies with velocity. In this study, surface temperature rise due to frictional heating in lubrication is calculated with various velocities. Surface film shearing and dry solid asperity contact are used to simulate the change of frictional heat in lubricated contact

Fabrication of Embedded Thermocouple Sensor and Experimental Study on Measurement of Interface Temperature for Dry Friction (임베디드 서모커플 센서 제조 및 미끄럼 마찰 계면온도 측정에 관한 실험적 연구)

  • Jang, Beomtaek;Lim, Youngheon;Kim, Seocksam
    • Tribology and Lubricants
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    • v.29 no.6
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    • pp.372-377
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    • 2013
  • This study investigated the interface temperatures for the sliding friction of three types of pins fabricated with thermocouple wires by the suction casting method. Optical microscopy was used to examine the surrounding material state at the bonding interface with the thermocouple wires. Friction tests were performed under dry sliding conditions against stainless steel 304 at nominal stresses of 1.42-4.25 MPa and sliding speeds of 0.5-1.25 m/s. Tribological data were collected using a custom-made pin-on-disk apparatus that measured the interface temperature and corresponding friction coefficient. Static tests were performed to demonstrate the functionality and reliability of the thermocouple wires-combined temperature sensor (TCTS). Each TCTS showed good linearity and sensitivity and very similar response times for the thermocouple and critical temperature during sliding friction.

A Study for Estimation of the Surface Temperature Rise Using the FVM and Semi-Infinite Solid Analysis (FVM과 반무한체 해석을 이용한 표면온도예측에 관한 연구)

  • 김태완;이상돈;조용주
    • Tribology and Lubricants
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    • v.18 no.6
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    • pp.389-395
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    • 2002
  • The surface temperature at the interface of bodies in a sliding contact is one of the most important factors influencing the behavior of machine components. The calculation of the surface temperature at a sliding contact interface has been an interesting and important subject for tribologist. Temperature analyses were usually performed under the consideration contacted two bodies as semi-infinite. But the analysis was difficulty in being applied to finite body and considering the boundary condition. In this study, contact temperature rise of two finite bodies and surfaces due to frictional heating under the rectangular and the circular sliding contact is calculated. Heat partition factor is calculated using semi-infinite solid analysis and the temperature of the finite bodies is calculated using FVM. It will be shown that Most frictional heat in the fore part of contact region for sliding direction is conducted into body that has a moving heat source and the site of the maximum temperature rise moves to the opposite direction of sliding during sliding.

A Study for Estimation of the Surface Temperature Rise Using the FVM and Semi-Infinite Solid Analysis (FVM과 반무한체 해석을 이용한 표면온도예측에 관한 연구)

  • 이상돈;김태완;조용주
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.11a
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    • pp.260-266
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    • 2001
  • The surface temperature at the interface of bodies in a sliding contact is one of the most important factors influencing the behavior of machine components. So the calculation of the surface temperature at a sliding contact interface has long been an interesting and important subject for tribologist. Several methods for calculating surface temperature have been devised. Several numerical methods have been used to predict the temperature rise of sliding surface. but those need much time to calculate. In this study to reduce the calculation time the hybrid method using both semi-infinite solid analysis and FVM was used. It is founded that the computing time of hybrid method was shorter than that of FVM.

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A Study for 3D Temperature Analysis between sphere and rough surface with Measured Temperatures (구와 거친표면의 미끄럼 접촉 온도해석 및 실험에 관한 연구)

  • Han T-H;Lee S-D;Kim T-W;Cho Y-J
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2003.11a
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    • pp.97-104
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    • 2003
  • The surface temperature at the interface of bodies in a sliding contact is one of the most important factors influencing the behavior of machine components. So the calculation of the surface temperature at a sliding contact interface has long been an interesting and important subject for tribologist. In this study to verify estimation of temperature rising, calculated temperatures were compared with measured temperatures. It is possible to calculate bulk and flash temperature.

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Sliding We3f Properties for 5%Co-5%V-1%Nb High Speed Steel by Powder Metallurgy at High Temperature (5%Co-5%V-1%Nb 분말고속도공구강의 고온 미끄럼마모특성)

  • 이한영;김용진;배종수
    • Tribology and Lubricants
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    • v.19 no.3
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    • pp.151-158
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    • 2003
  • In metal cutting at the tool-chip interface, friction generates considerable amount of heat. Thus, the knowledge of wear properties of cutting tool material in high temperature has been as one of important factors in need of clarification. The authors presented the wear properties of 5%Co-5%V-1%Nb high speed steel, fabricated by powder metallurgy, in room temperature in previous articles. The objective of this paper is to clarify the effects of temperature on its wear properties. Wear tests in sliding conditions under various temperatures have been conducted using the pin-on-disc type wear test machine. The results indicate that the wear properties of 5%Co-5%V-1%Nb high speed steel in high temperature as well as in room temperature are excellent. It may be deduced that the oxide layer formed on worn surface at high temperature is stable enough to prevent wear due to the high temperature strength of its matrix.

Thermoelastic Instability of the Layer Sliding between Two Non-conducting Half-planes (비전도 반평판 사이에서 미끄럼 운동하는 평판 층의 열탄성 불안정성)

  • 하태원;조용구;김흥섭;이정윤;오재응
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.483-488
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    • 2003
  • Frictional heating in brakes causes thermoelastic distortion of the contacting bodies and hence affects the contact pressure distribution. The resulting thermo-mechanical coupling can cause thermoelastic instability (TEI) if the sliding speed is sufficiently high, leading to non-uniform heating called hot spots and low frequency vibration known as hot judder. The vibration of brakes to the known phenomenon of frictionally-excited thermoelastic instability is estimated studying the interface temperature and pressure evolution with time. A simple model has been considered where a layer with half-thickness ${\alpha}$ slides with speed V between two half-planes which are rigid and non-conducting. The advantage of this properly simple model permits us to deduce analytically the critical conditions for the onset of instability, which is the relation between the critical speed and the growth rate of the interface temperature and pressure. Symmetrical component of pressure and temperature distribution at the layer interfaces can be more unstable than antisymmetrical component. As the thickness ${\alpha}$ reduces, the system becomes more apt to thermoelastic instability. Moreover, the evolution of the system beyond the critical conditions has shown that even if low frequency perturbations are associated with low critical speed, it might be less critical than high frequency perturbations if the working sliding speed is much larger than the actual critical speed of the system.

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Sliding Wear Characteristics of High Speed Steel by Powder Metallurgy under several Testing Temperature (분말고속도공구강의 작동온도에 따른 미끄럼마모특성해석)

  • 이한영;노정균;배종수;김용진
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.135-140
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    • 2001
  • In metal cutting at the tool-chip interface, friction generates considerable amount of heat. Thus, tile .knowledge of wear properties or the cutting tool material in high temperature has been known as one of tile important factors in need of clarification. The authors presented the wear properties of 5%V-5%Co-1%Nb high speed steel, fabricated by powder metallurgy, in room temperature in a previous article. The objective of this paper is to clarify tile effects of temperature ell its wear properties. Wear tests in sliding conditions under various temperatures have been conducted. The results indicate that tile wear properties of tile tool material in high temperature as well as in room temperature are excellent. It may be deduced that the oxide layer formed on the vol-n surface at high temperature is stable enough to prevent wear due to tile high temperature strength of its matrix.

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A Study on the High Temperature Deformation and the Cavity Initiation of Gamma TiAl Alloy ($\gamma$-TiAl 합금의 고온변형 및 Cavity 형성 연구)

  • Kim J. H.;Ha T. K.;Chang Y. W.;Lee C. S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.172-175
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    • 2001
  • The high temperature deformation behavior of two-phase gamma TiAl alloy has been investigated with the variation of temperature and ${\gamma}/{\alpha}_2$ volume fraction. For this purpose, a series of load relaxation tests and tensile tests have been conducted at temperature ranging from 800 to $1050^{\circ}C$. In the early stage of the deformation as in the load relaxation test experimental flow curves of the fine-grained TiAl alloy are well fitted with the combined curves of two processes (grain matrix deformation and dislocation climb) in the inelastic deformation theory. The evidence of grain boundary sliding has not been observed at this stage. However, when the amount of deformation is large (${\epsilon}{\approx}$ 0.8), flow curves significantly changes its shape indicating that grain boundary sliding also operates at this stage, which has been attributed to the occurrence of dynamic recrystallization during the deformation. With the increase in the volume fraction of ${\alpha}_2$-phase, the flow stress for grain matrix deformation increases since ${\alpha}_2$-Phase is considered as hard phase acting as barrier for dislocation movement. It is considered that cavity initiation is more probable to occur at ${\alpha}_2/{\gamma}$ interface rather than at ${\gamma}/{\gamma}$ interface.

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Thermoelastic Instability of the Layer Sliding between Two Rigid Non-conducting Half-planes (단단한 비전도 반평판 사이에서 미끄럼 운동하는 평판층의 열탄성 불안정성)

  • 오재응;하태원;조용구;김흥섭;이정윤
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.114-121
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    • 2004
  • Frictional heating in brakes causes thermoelastic distortion of the contacting bodies and hence affects the contact pressure distribution. The resulting thermo-mechanical coupling can cause thermoelastic instability (TEI) if the sliding speed is sufficiently high, leading to non-uniform heating called hot spots and low frequency vibration known as hot judder. The vibration of brakes to the known phenomenon of frictionally-excited thermoelastic instability is estimated studying the interface temperature and pressure evolution with time. A simple model has been considered where a layer with half-thickness$\alpha$slides with speed V between two half-planes which are rigid and non-conducting. The advantage of this properlysimple model permits us to deduce analytically the critical conditions for the onset of instability, which is the relation between the critical speed and the growth rate of the interface temperature and pressure. Symmetrical component of pressure and temperature distribution at the layer interfaces can be more unstable than antisymmetrical component. As the thickness $\alpha$ reduces, the system becomes more apt to thermoelastic instability. For perturbations with wave number smaller than the critical$m_{cr}$ the temperature increases with m vice versa for perturbations with wave number larges than $m_{cr}$ , the temperature decreases with m.