Tribology in Design student presentation Tribology in Design student presentation 2

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1. Walchand College of Engineering, Sangli (Government-Aided Autonomous Institute) Name: Avinash Mahadev Benadi PRN: 242519001 Course Name: Tribology in Design Department: Mechanical Degree Yr: 2024-26 Specialization: Design Guided By: Mr. Prabhakar Maskar Assistant Professor Topic Name: Discuss the properties of Lubricant 1

2. Introduction to Lubricants Viscosity and its Unit Viscosity Measurement Viscosity Index (VI) Viscosity Index Calculation Factors Affecting Viscosity Summary 2

3. 3 Introduction to Lubricants Lubricants- Substances (usually liquids) used to reduce friction between surfaces in contact It enhancing the performance and longevity of machinery.. Importance- They provide smooth operation, protect against wear, prevent rust, and help in cooling machinery. Properties- High Boiling and Low freezing High viscosity index Thermal stability Hydraulic stability Corrosion prevention Low volatility High flash/Fire point

4. 4 Viscosity- What is it? Definition- Viscosity is the measure of a fluid's resistance to flow. It is a key property of lubricants. Analogy : Think of a thick syrup compared to water. Syrup flows slower because it has higher viscosity.

5. 5 Viscosity Measurement Kinematic Viscosity Measured using a viscometer, calculating the time it takes for the liquid to flow through a tube under gravity. Dynamic Viscosity Measured using a viscometer or rheometer, determining the force needed to move the liquid.

6. 6 Viscosity Index (VI) Definition The Viscosity Index is a measure of how much the viscosity of a lubricant changes with temperature. Importance : A higher VI indicates less change in viscosity with temperature variation.

7. 7 Viscosity Index Calculation Index Scale- High VI Lubricants : Maintain a more stable viscosity across a wide temperature range. Example: Synthetic oils. Low VI Lubricants: Viscosity changes significantly with temperature fluctuations. Example: Conventional oils Formula- L= Viscosity at 40°C of a reference oil with a low VI. U= Viscosity at 100°C of the same reference oil. L' and U' are the viscosities of the test oil.

8. 8 Factors Affecting Viscosity Temperature : As temperature increases, viscosity typically decreases (oil becomes thinner). Pressure : Higher pressures can increase viscosity. Additives : Some additives help in improving the viscosity index or prevent viscosity breakdown over time.

9. 9 Summary Lubricant is a substance used to reduce friction between moving surfaces, such as engine parts in vehicles, by providing a slippery film Viscosity is crucial for determining how lubricants perform under different operational conditions. The proper selection of viscosity ensures efficiency and protection of machinery.

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