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Experimental: Static Friction 1 S phero-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 µm N ormal loads Р 1 = 98,1 N; Р 2 = 196,2 N; Р 3 = 245,25 N; Р 4 = 294,3 N.
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Experimental: Static Friction 1Sphero-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 Fig.6. Static COF µо vs Sn content Fig.5. Static COF µо vs normal load P
Static Friction 2 Fig. 8 . COF jump Δµ vs Sn content Fig. 9. Static friction force Тоvs static contact duration Fig.10. Static friction force Тоvs static contact duration for specimen without Snfor specimen with 0,051% Sn content
Fig. 2 Device for dynamic friction study: one way translationat various loads and sliding speeds Dynamic friction 1 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
Dynamic friction 2 Fig.13.COF vs sliding speed at Р = 98 N loadFig.14.COF vs sliding speed at Р = 294N load Conclusion Dynamic friction
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.
AcknowledgementsPart 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.
Mara Kandeva, Tribology Center,Dept., Technical University-Sofia, kandevam@gmail.com Boryana Ivanova, Dept. Material Science and Technology, TechnicalUniversity-Sofiabsaykova@tu-sofia.bg Dimitar Karastoyanov, Institute for Information and Communication Technologies, Bulgarian Academy of Sciences, Sofia,dimikara@abv.bg Emilia Assenova, Society of Bulgarian Tribologists, emiass@abv.bg THANK YOU FOR YOUR ATTENTION