• Semester 5, position 4

The student attending this course should: • Comprehend the significance of friction, wear and lubrication (tribology keywords) and the problems connected with it, the field of construction and maintenance of mechanical parts and systems; • Master the fundamental knowledge in these areas of tribology in order to decide the merits of the choice of materials and lubricants for the construction and tribological components; • Solve problems related to the prevention of wear and competently decide on techniques to improve tribological properties of materials and lubrication technologies.

Based on the mastered knowledge the student is qualified to: • Identifies and critically analyze the basic causes of energy and material dissipation in some mechanical system; • Recognize the dominant type of wear in some mechanical system and to propose appropriate measures for its reduction; • Choose the appropriate type of material for the basic tribological elements (plain bearings, roller bearings and gears); • Describes and distinguishes the most common surface modification and coating deposition methods; • Explain the influences of temperature and pressure on the value of the viscosity (lubricants rheology); • Describes and distinguishes the basic types and methods of lubrication with their characteristics.

• Tribology as a science and technical disciplines and techno-economical importance of tribology. • Properties of surfaces and the nature of contact of two bodies. • Friction – the basic causes and principles; Friction of metals and non-metals. • Wear – mechanisms and types; Wear calculation and measuring methods; Wear prevention. • Tribological materials (types and application in tribology); Characteristics and selection of materials for tribological components. • Technologies for improving the tribological properties of materials (surface modifications and coatings). • Lubricants – role, type, classification and basic properties; Rheology of lubricants. • Forms and types of lubrication; Hydrostatic, hydrodynamic, elastohydrodynamic and boundary lubrication. • Lubrication systems (tasks and roles; procedures and classification; elements definition) and lubricants selection. • Lubrication services organization and lubricants ecology.

• Tribological losses in the industry and transportation; Tribological improvements studies. • Characterization of the tribological surfaces; Methods and apparatus for surface roughness measuring; Surface roughness standards; Influence of material processing and machining on the surface roughness; Properties of surface layers. • Presentation of worn surfaces and machine parts failure due to wear, and wear products (debris). • Examples of different solutions for improving the tribological properties of materials. • Laboratory practice: “Experimental evaluation of roughness, friction and wear”; Measuring of roughness and coefficient of friction and wear values for different materials and test conditions. • Classifications and specifications of lubricants; Methods for lubricants testing. • Laboratory practice: “Experimental investigation of the rheological properties of lubricants”; Determination of the rheological properties of lubricating oils (viscosity, viscosity-temperature dependence, viscosity index) and greases (shear stress and shear rate gradient, apparent viscosity). • Essay writing.

No special requirements.

1. --, Handouts for each lecture. 2. A. Rac, Fundamentals of Tribology, Faculty of Mechanical Engineering, Belgrade, 1991, (in Serbian). 3. A. Rac, Lubricants and Machine Lubrications, Faculty of Mechanical Engineering, Belgrade, 2007, (in Serbian). 4. A. Rac, A. Vencl, Sliding Bearing Metallic Materials – Mechanical and Tribological Properties, Faculty of Mechanical Engineering, Belgrade, 2004, (in Serbian). 5. Pin-on disc tribometer; Block-on-ring disk tribometer; Four Ball machine. 6. Viscometer for liquid lubricants; Pressure grease viscometer.

Total assigned hours: 75

New material: 20
Elaboration and examples (recapitulation): 10

Auditory exercises: 0
Laboratory exercises: 12
Calculation tasks: 0
Seminar paper: 5
Project: 0
Consultations: 0
Discussion/workshop: 13
Research study work: 0

Review and grading of calculation tasks: 0
Review and grading of lab reports: 2
Review and grading of seminar papers: 4
Review and grading of the project: 0
Test: 0
Test: 4
Final exam: 5

Activity during lectures: 5
Test/test: 45
Laboratory practice: 10
Calculation tasks: 0
Seminar paper: 10
Project: 0
Final exam: 30
Requirement for taking the exam (required number of points): 35

B. Ivković, А. Rac, Tribology, Yugoslav Tribology Society, Kragujevac, 1995 (in Serbian).; J. Halling, Principles of Tribology, The MacMillan Press Ltd., London, 1975.; D.F. Moore, Principles and Applications of Tribology, Pergamon Press, Oxford, 1975.; B. Bhushan, Principles and Applications of Tribology, John Wiley & Sons, New York, 1999.; A.R. Lansdown, Lubrication – A Practical Guide to Lubricant Selection, Pergamon Press, Oxford, 1982.