Comparison of tribological characteristics between aluminum alloys and polytetrafluoroethylene composites journal bearings under mineral oil lubrication

• Published in: Journal of mechanical science and technology 2010, 24(8), , pp.1631-1635
• Main Authors: Ku, Boncheol, Park, Youngdo, Sung, Chiun, Han, Youngchul, Park, Junghoon, Hwang, Yujin, Lee, Jungeun, Lee, Jaekeun, Kim, Hyeongseok, Ahn, Sungyoung, Kim, Soo Hyung
• Format: Article
• Language: English
• Subjects: Alloys; Aluminum base alloys; Applied sciences; Bearings, bushings, rolling bearings; Composites; Control; Drives; Dynamical Systems; Engineering; Exact sciences and technology; Forms of application and semi-finished materials; Friction; Friction, wear, lubrication; Inductively coupled plasma; Industrial and Production Engineering; Journal bearings; Lubrication; Machine components; Mechanical Engineering; Mechanical engineering. Machine design; Mechanical properties; Physical properties; Polymer industry, paints, wood; Polytetrafluoroethylenes; Properties and testing; Technology of polymers; Tribology; Vibration; 기계공학
• ISSN: 1738-494X; 1976-3824
• DOI: 10.1007/s12206-010-0508-z

This study examined the tribological behavior of journal bearings made from polytetrafluoroethylene (PTFE) composites and aluminum (Al) alloys. The PTFE composite journal bearings consisted of a steel backing with a thickness of 1.6 mm, a middle layer of sintered porous bronze with a thickness of 0.24∼0.27 mm, and a surface layer of PTFE filled with fluorinated ethylene propylene (FEP) powder and carbon fibers with a thickness 0.06∼0.14 mm. The other was an aluminum alloy journal bearing consisted of a steel backing with a thickness of 1.5 mm and a surface layer of an Al-6Sn-6Si alloy with a thickness 0.35∼0.75 mm. A series of lubrication tests were performed using a journal bearing tester under various normal loads. The tribological properties for each journal bearing were evaluated by measuring the lubricant oil temperature and friction coefficient as a function of the applied normal load. In addition, the chemical compositions and microstructures of the journal bearing materials used in this study was analyzed by inductively coupled plasma (ICP), optical microscopy (OM), and scanning electron microscopy (SEM), respectively. The experimental results showed that the Al alloy journal bearings reduce the friction coefficient by 28 % compared to the PTFE composites bearings. In addition, the Al alloy journal bearing worked properly at the maximum load of ∼ 8,000 N without adhesion. However, the PTFE composite journal bearings exhibited strong adhesion at the loads ranging from 6300 to 8000 N. This suggests that the Al alloy is a more promising material in journal bearings than PTFE composites.