GRAFİT VE BRONZ DOLGULU BİR PTFE KAYMALI YATAĞIN KURU SÜRTÜNME ÖZELLİKLERİNİN İNCELENMESİ

Öz

PTFE, öncelikle düşük bir sürtünme katsayısına sahip olması ve çok geniş bir sıcaklık sahası boyunca stick-slip hareketine maruz kalmaması nedeniyle kuru yatak malzemesi olarak yaygın bir şekilde kullanılmaktadır. Bu çalışmada grafit ve bronz katkılı PTFE'den imal edilmiş bir kaymalı yatak burcunun çelik bir muyluya karşı sürtünme katsayısı bir deney düzeneğinde tayin edilip, hız ve sıcaklık artışıyla değişimleri incelenmiştir. Deneyler sonucu sürtünme katsayısının nisbeten küçük hız ve basınçlar sahasında hemen hemen sabit kaldığı (yaklaşık 0,19) ve sürtünme katsayısı üzerinde sıcaklık artışının hız artışına göre daha etkili olduğu bulunmuştur. Ayrıca sabit bir pv değeri için belirli bir sıcaklığa kadar "küçük hız + büyük basınç" kombinasyonunun daha düşük sürtünme katsayıları sağladığı bulunmuştur.

Anahtar Kelimeler

• Ptfe,grafit,bronz,kaymalı yatak,sürtünme katsayısı

Investigation of dry friction properties of graphite and bronze filled PTFE journal bearing

Öz

PTFE is widely used as a dry-bearing material since it does not subject to the stick-slip motion along the wide temperature range, and has a low coefficient of friction. In this study, the coefficient of friction between the bearing sleeve made of graphite and bronze filled PTFE compound and the steel journal is determined on a test rig and then its dependence upon the velocity and temperature increase is investigated. As a result of the tests, it was found that the coefficient of friction was almost constant (about 0.19) in the relatively small velocity and pressure area and the temperature increase over the coefficient of friction was more effective than the increase in velocity. It has also been found that the combination of "small velocity + large pressure" up to a certain temperature for a constant pv value provides lower friction coefficients. 

Anahtar Kelimeler

• PTFE,graphite,bronze,journal bearing,the coefficient of friction

Kaynakça

1. Anderson, J.C. (1986) The wear and friction of commercial polymers and composites. In: Friedrich, K. (Ed.), Friction and Wear of Polymer Composites, Composite materials series 1, Elsevier, Amsterdam, 329–362.
2. Blanchet, T.A., Peng, Y. and Nablo, S.V. (1998) Tribology Letters, 4, 87–94.
3. Chung, D.D.L. (2002) Graphite. Journal of Materials Science, 37, 1475–1489.
4. Desale, D.D. and Pawar, H.B. (2018) Performance Analysis of Polytetrafluoroethylene as Journal Bearing Material. Procedia Manufacturing, 20, 414-419.
5. Erhard, G. und Strickle, E. (1972) Gleitelemente aus Thermoplastischen Kunststoffen. BASF, Sonderdruck aus der Zeitschrift Kunststoffe, 1-21, s684d, 10.
6. Evans, D.C. (1980) Self-Lubricating Bearings : Dry Bearings, The Glacier Metal Co. Ltd., Technical File No.79, Engineering, I-VI.
7. Hamrock, B.J. (1994) Fundamentals of Fluid Film Lubrication, McGraw-Hill, N.Y., 97-100.
8. Lancaster, J.K. (1979) Accelerated Wear Testing of PTFE Composite Bearing Materials. Tribology International, April, 65-75.

9. Low, M.B.J. (1979) The effect of the transfer film on the friction and wear of dry bearing materials for a power plant application. Wear 52, 347-363.
10. Parker, E.R. (1963) Materials for Missiles and Spacecraft, McGraw-Hill, N.Y., 312-315.
11. Strong, A.B. (1996) Plastics: Materials and Processing, Prentice-Hall, N.J., 9-201.
12. Stuart, B.H. (1998) Tribological studies of poly(ether ether ketone) blends. Tribology International, 31(11), 647–651.
13. ___________ (1993) Sealing Handbook, 3353/E, Parker-Pradifa GmbH, Bietigheim-Bissingen, Germany, 121-125.
14. Tanaka, K. (1986) Effects of various fillers on the friction and wear of PTFE-based composites. In: Friedrich, K. (Ed.), Friction and Wear of Polymer Composites, Elsevier, Amsterdam, The Netherlands, 137–174.
15. Tevrüz, T. (1998) Tribological behaviours of carbon filled polytetrafluoroethylene (PTFE) dry journal bearings. Wear, 221, 61-68.
16. Tevrüz, T. (1999) Tribological behaviours of bronze-filled polytetrafluoroethylene dry journal bearings. Wear, 230, 61-69.
17. Unal, H., Mimaroglu, A., Kadıoglu, U. and Ekiz, H. (2004) Sliding friction and wear behaviour of polytetrafluoroethylene and its composites under dry conditions. Materials & Design, 25(3), 239-245.
18. Unal, H., Sen, U. and Mimaroglu, A. (2006) An approach to friction and wear properties of polytetrafluoroethylene composite. Materials & Design, 27(8), 694-699.
19. Wang, C.B., Yan, M.F. and Wang, Y. (2004) The influence of metal surface composition on the tribological properties of filled PTFE/steel couples. Tribology International, 37(8), 645-650.
20. Wilkens, W. and Kranz, O. (1970) The Formation of Gases due to the Sliding Friction of Teflon on Steel in Ultrahigh Vacuum. Wear, 15, 215-227.
21. Yamaguchi, Y. (1990) Tribology of plastic materials: Their characteristics and applications to sliding components, Elsevier Science, Amsterdam.