**4. Lubricant analysis**

Lubricant analysis primarily refers to the characterization and evaluation of the lubricant for various physical, chemical and performance properties in all stages of its life cycle. For solid lubricants and coatings, the analysis includes determining the composition and structure by using a range of spectroscopic and microscopic observation methods as well as measuring the coating consistency and thickness applying non-destructive evaluation techniques. Standardized tribological lab tests are used to evaluate their performance. Once a candidate material is identified, larger-scale bench testing, such as engine tests, are conducted.

For liquid lubricants, characterization is done to a much larger extent due to the large variety of applications and the implication of chemistry of the formulated oils on the machine elements performance and the overall performance of the entire equipment/machine or engine. The lubricant analysis can be classified as physical and chemical characteristics evaluation, Performance test evaluation and Engine Test evaluation as summarized in **Table 2** [2]. Additionally, end users also develop their in-house in-service lubricant analysis to monitor and maintain the condition of the lubricant. The objective of such analysis is to ensure optimum performance, achieve expected life of the equipment as well as the lubricant flowing through it.

### **5. Future trends**

Current automotive lubricants are optimized for internal combustion engines and drive trains. Electric vehicles (EVs) which use electric motors possess new challenges of lubrication such as high-power density of the small gear box which require efficient cooling. Hydro lubricants and synthetic gear oils are excellent candidates for such application but may pose sealing issues which requires innovative solutions. Lubricants are also required in the rolling element bearings of EVs that must stop electro-erosion

#### *Tribology in Materials and Manufacturing - Wear, Friction and Lubrication*

caused by high frequency high energy discharges by being conductive. Ionic liquids are having shown good performance in preventing built up of potential [17].

The future for lubricants formulation, manufacturing and end-use is oriented towards efficiency in terms of cost and time, customized and optimized for each individual tribo-system and run reliably for even longer drain interval time. New industrial lubricants must meet stringent regulations and guarantee ecological sustainability, and climate change actions. Hence, new lubricants will contribute to 'Green Tribology'.

Tribology of lubricants plays a significant role in technology and economics of industrial development. As the fourth industrial revolution 'Industry 4.0' (combines automation with the internet of things) is in progress, several concepts can be extended to lubricant and lubricant additive development and evaluation. For example new electronic smart sensors can be used for lubricant analysis and condition monitoring. The information of various performance parameters can be stored as data and transferred to the stakeholders and decision-making points using the information and communication technologies involved in Industry 4.0. such as internet and wireless connections to and via several electronic devices. Continuous monitoring can also aid in corrective measures. In-service lubricant performance testing and evaluation generates big quantities of data from various equipment and sensors. Therefore, 'Big Data' concepts can be applied in several ways. One such example can be combining lubricant data with machine data, another can be correlation study of amount of soot produced, change in oil viscosity, friction, wear of an engine. The benefits of Industry 4.0 include shorter lubricant development time, reduced number of trials, lubricant performance prediction through chemical and physical modeling and simulations. This will transform product development process from being empirically driven to using data and simulation driven approach.

## **6. Conclusion**

Lubricants are vital for the tribological life of the machine elements. As modern machine elements are required to perform in heavy-duty applications in a wide range of environments, newer, better and environmentally sustainable lubricants are required to be designed. Lubricant additives are therefore considered as lubrication engineering design components. Lubricant additives are designed and optimized to meet the performance requirements of the equipment or engine. Various types of lubricant additives and their functional properties were discussed. They are designed to provide oxidation resistance, high temperature viscosity, energy and fuel efficiency among others. Lubricant or grease therefore are a complex mixture of several components blended carefully together to meet the performance requirements. The different components can have synergistic or antagonistic effects due to chemical interactions or competition at the metal surface or among themselves. Therefore, formulation of lubricants requires considerable expertise and expensive performance testing. Green Tribology and Industry 4.0 era will steer the lubricant development, use and disposal.

### **Acknowledgements**

This chapter could not be published without the exceptional support of Prof. Paul B. Davies (University of Cambridge, UK) and substantial industry inputs and scrutiny by Mr. Tony D. Smith (Castrol, UK).

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**Author details**

Debashis Puhan

Department of Chemistry, University of Cambridge, Cambridge, United Kingdom

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: dp617@cam.ac.uk

provided the original work is properly cited.

*Lubricant and Lubricant Additives*

*DOI: http://dx.doi.org/10.5772/intechopen.93830*

*Lubricant and Lubricant Additives DOI: http://dx.doi.org/10.5772/intechopen.93830*

*Tribology in Materials and Manufacturing - Wear, Friction and Lubrication*

'Green Tribology'.

driven approach.

**6. Conclusion**

the lubricant development, use and disposal.

scrutiny by Mr. Tony D. Smith (Castrol, UK).

**Acknowledgements**

having shown good performance in preventing built up of potential [17].

caused by high frequency high energy discharges by being conductive. Ionic liquids are

The future for lubricants formulation, manufacturing and end-use is oriented towards efficiency in terms of cost and time, customized and optimized for each individual tribo-system and run reliably for even longer drain interval time. New industrial lubricants must meet stringent regulations and guarantee ecological sustainability, and climate change actions. Hence, new lubricants will contribute to

Tribology of lubricants plays a significant role in technology and economics of industrial development. As the fourth industrial revolution 'Industry 4.0' (combines automation with the internet of things) is in progress, several concepts can be extended to lubricant and lubricant additive development and evaluation. For example new electronic smart sensors can be used for lubricant analysis and condition monitoring. The information of various performance parameters can be stored as data and transferred to the stakeholders and decision-making points using the information and communication technologies involved in Industry 4.0. such as internet and wireless connections to and via several electronic devices. Continuous monitoring can also aid in corrective measures. In-service lubricant performance testing and evaluation generates big quantities of data from various equipment and sensors. Therefore, 'Big Data' concepts can be applied in several ways. One such example can be combining lubricant data with machine data, another can be correlation study of amount of soot produced, change in oil viscosity, friction, wear of an engine. The benefits of Industry 4.0 include shorter lubricant development time, reduced number of trials, lubricant performance prediction through chemical and physical modeling and simulations. This will transform product development process from being empirically driven to using data and simulation

Lubricants are vital for the tribological life of the machine elements. As modern

This chapter could not be published without the exceptional support of Prof. Paul B. Davies (University of Cambridge, UK) and substantial industry inputs and

machine elements are required to perform in heavy-duty applications in a wide range of environments, newer, better and environmentally sustainable lubricants are required to be designed. Lubricant additives are therefore considered as lubrication engineering design components. Lubricant additives are designed and optimized to meet the performance requirements of the equipment or engine. Various types of lubricant additives and their functional properties were discussed. They are designed to provide oxidation resistance, high temperature viscosity, energy and fuel efficiency among others. Lubricant or grease therefore are a complex mixture of several components blended carefully together to meet the performance requirements. The different components can have synergistic or antagonistic effects due to chemical interactions or competition at the metal surface or among themselves. Therefore, formulation of lubricants requires considerable expertise and expensive performance testing. Green Tribology and Industry 4.0 era will steer

**182**
