Fig . 5 . Static COF µ о vs normal load P
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Transcript of Fig . 5 . Static COF µ о vs normal load P
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014
MaTri'14
Static and Dynamic Friction of Sphero-graphite Cast Iron with Sn Microalloy
Mara Kandeva1, Boryana Ivanova2, Dimitar Karastoyanov3, Emilia Assenova4
1Tribology Center, Technical University - Sofia, 2Dept. Material Science and Technology, Technical University – Sofia
3Institute for Information and Communication Technologies, Bulgarian Academy of Sciences, Sofia
4Society of Bulgarian Tribologists, Sofia
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Introduction Sphero-graphite cast iron is a composite construction material with good mechanical characteristics. Sn microalloying improves of strength, hardness, etc., but also tribological characteristics friction and wear.Aim: study of the influence of Sn quantity in sphero-graphite cast iron during : preliminary displacement (static friction) and motion (dynamic friction). Tasks:1. Development of procedures and devices for static and dynamic dry friction study at various normal loads and sliding velocity;2. Study of friction force and coefficient at static friction and dynamic friction.
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Materials, procedures and devices
Fig.1. Scheme of the device for static friction study
Fig.2. Scheme of the device for dynamic friction study
Specimen № 0 1 2 3 4
Sn, % 0 0,018 0,020 0,032 0,051
НВ 179 197 203 262 277
Table 1: Specimens’ Sn content and hardness HB
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Materials, procedures and devices
Fig.3 Microstructure of the specimens:
(a) 0% Sn , (b) 0,018 % Sn, (c) 0,020 % Sn, (d) 0,032% Sn, (e) 0,051% Sn
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Experimental: Static Friction 1
Sphero-graphite non-heated cast iron specimens, Sn content: 0%, 0.018%, 0.020%, 0.032%, 0.051%Counterbody: Steel alloy, НВ 450 ; roughness Ra = 0,432 µmNormal loads Р1 = 98,1 N; Р2 = 196,2 N; Р3 = 245,25 N; Р4 = 294,3 N
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о
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0,032% Sn 0,051% Sn
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Р=98 N P=196 N P=245 N P=294 N
Fig.5. Static COF µо vs normal load P Fig.6. Static COF µо vs Sn content
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Static Friction 2
0,0020,0070,0120,0170,0220,0270,032
0 0,01 0,02 0,03 0,04 0,05
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съдържание на калай % Sn
98 N 196 N 245 N 294 N
Fig. 7. COF jump Δµ vs load P Fig. 8 . COF jump Δµ vs Sn content
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Време на неподвижен контакт, s
P=98 N P=196 N P=294 N
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P=98 N P=196 N P=294 N
Fig. 9. Static friction force То vs static contact duration Fig.10. Static friction force То vs static contact duration
for specimen without Sn for specimen with 0,051% Sn content
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Static friction conclusion …..
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Dynamic friction 1
Fig. 2 Device for dynamic friction study: one way translation at various loads and sliding speeds
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нт н
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нормално натоварване Р
0%Sn 0,018%Sn 0,02%Sn
0,032%Sn 0,051%Sn
Fig.11.COF vs load P, sliding speed V = 7,2 cm/min Fig.12 COF vs Sn content P, sliding speed V = 7,2 cm/min for specimen without Sn for specimen with 0,051% Sn content
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101520253035
0 10 20 30 40 50стат
ична
сил
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три
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N
време на неподвижен контакт, s
P=98 N P=196 N P=294 N
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Dynamic friction 2
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скорост на плъзгане V cm/min
0% Sn 0,051% Sn
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нт н
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0% Sn 0,051% Sn
Fig.13. COF vs sliding speed at Р = 98 N load Fig.14. COF vs sliding speed at Р = 294 N load
Conclusion Dynamic friction
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Conclusion1. Results are obtained for the variation of static and dynamic friction coefficient in function of load and Sn content in the cast iron. 2. Increasing of Sn leads to nonlinear decrease in static COF and friction jump passing through a minimum. 3. A minimum is also observed in the variation of the dynamic COF at small sliding speeds.
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Acknowledgements
Part of the study is related to the 7 FP Project „Acom In (Advanced Computing Innovations)” coordinated by the Institute of Information and Communication Technologies at the Bulgarian Academy of Science and the project No BG051PO001-3.3.06-0046 “Development support of PhD students, postdoctoral researchers and young scientists in the field of virtual engineering and industrial technologies”. The project is realized with the financial support of the Operational Program Human Resources Development, co-financed by the European Union through the European Social Fund.
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
THANK YOU FOR YOUR ATTENTION
Mara Kandeva, Tribology Center, Dept., Technical University-Sofia, [email protected]
Boryana Ivanova, Dept. Material Science and Technology, Technical University-Sofia [email protected]
Dimitar Karastoyanov, Institute for Information and Communication Technologies, Bulgarian Academy of Sciences, Sofia, [email protected]
Emilia Assenova, Society of Bulgarian Tribologists, [email protected]
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Slide 13
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
Slide 14
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Slide 15, proba
2nd Austrian-Indian-Symposium on Materials Science and TribologyWiener Neustadt, 26th – 29th May 2014MaTri'14
THANK YOU FOR YOUR ATTENTION