Tribology and Sustainability

Jitendra Kumar Katiyar, Mir Irfan Ul Haq, Ankush Raina, S. Jayalakshmi, R. Arvind Singh, Jitendra Kumar Katiyar, Mir Irfan Ul Haq, Ankush Raina, S. Jayalakshmi, R. Arvind Singh

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9781000435566
• Edition: 1
• Topic: Biowissenschaften
• Subtopic: Umweltschutz

Tribology and Sustainability brings a vision of promoting a greener, cleaner and eco-friendly environment by highlighting sustainable solutions in tribology via the development of self-lubricating materials, green additives in lubricants, natural fibre-reinforced materials and biomimetic approaches. Backed by supporting schematic diagrams, data tables and illustrations for easy understanding, the book focuses on recent advancements in tribology and sustainability. Global sustainability and regional requirements are addressed through chapters on natural composites, green lubricants, biomedical systems and wind energy systems, with a dedicated chapter on a global sustainability scenario.

FEATURES

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• Highlights sustainability via new tribological approaches and how such methods are essential

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• Covers the theoretical aspects of various tribological topics concerning mechanical and material designs for energy-efficient systems

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• Includes practical global sustainability based on the regional requirements of tribological research and sustainable impact

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• Reviews the tribology of green lubricants, green additives and lightweight materials

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• Discusses topics related to biomimetics and biotribology

Tribology and Sustainability will assist researchers, professionals and graduate students in tribology, surface engineering, mechanical design and materials engineering, including mechanical, aerospace, chemical and environmental engineering.

Section II

Sustainable Lubrication

9 Recent Progress in Vegetable Oil-Based Lubricants for Tribological Applications

Sooraj Singh Rawat and A. P. Harsha

Indian Institute of Technology (Banaras Hindu University)

Contents

9.1 Introduction

9.1.1 Function of Lubricants

9.1.2 Classification of Lubricants

9.1.3 Current Status and Lubricant Market

9.2 Basic Chemistry of Hydrocarbon

9.3 Basics of Vegetable Oil

9.3.1 Benefits and Drawbacks of Vegetable Oils over Mineral Oils

9.4 Processing of Vegetable Oils

9.5 Oxidation Stability

9.6 Role of Nanoadditives

9.7 Application of Vegetable Oil-Based Lubricants

9.8 Evaluation of Lubricants

9.8.1 Evaluation of Physicochemical Properties

9.8.2 Evaluation of Tribological Performance

9.8.3 Tribological Performance of Vegetable Oil-Based Lubricants

9.9 Summary

References

9.1 Introduction

The lubricants are natural lubricious substances. They protect the tribosurfaces against wear and minimize the risk of frequent breakdown. They also facilitate for smooth slide or roll of machine parts over each other and reduce the noise developed during the operation. The lubricant decreases the friction and direct interaction of asperities by establishing a tribofilm amid the interacting surfaces. The lubricants have many different functions, which are given in the later part (Section 9.1.1). Lubricant is an amalgamation of base stock and a package of additives. The percentage of additives in the lubricant is varied according to the severity of applications. Typically, a liquid lubricant is constituted of base oil and additives in the range 1–25 wt. % (Rizvi and Syed, 2009).

The mineral oil is a refined, purified and processed product of crude oil via the fractional distillation process. In conventional lubricants, mineral oils are preferred as base stock due to their low cost, readily available in abundance, excellent oxidation stability and availability in a variety of viscosities. Besides, crude oil has a finite source in the world, and it can be utilized until available. The dramatic growth in the industrial sector in the 21st century caused the increase in the depletion rate of crude oil, which results in an increase in the price. Furthermore, mineral oils are toxic, and their biodegradability is very poor (Panchal et al., 2017). Therefore, the disposal of mineral oil is hazardous to both terrestrial and aquatic ecosystems. The environmental threat in consequence of the disposal of mineral oil has arisen the interest in developing a suitable substitute for conventional lubricants and eco-friendly too. In view of the above, the lubricants are formulated with vegetable oil, which exhibit high viscosity index, low evaporation losses, high flash point, renewability, high biodegradability and the excellent lubrication performance in comparison with mineral oils (Fox and Stachowiak, 2007; Jayadas et al., 2007; Panchal et al., 2017; Shashidhara and Jayaram, 2010; Zulkifli et al., 2013a). The long fatty acid chains of vegetable oil and the presence of polar groups furnish to establish an excellent tribofilm at the interacting surfaces under boundary and hydrodynamic conditions (Sahoo and Biswas, 2009; Zachariah et al., 2020).

9.1.1 Function of Lubricants

The function of lubricants is varied according to the tribological situations. The prime purpose of the lubricants is to protect the interacting surfaces and control friction and wear. Nevertheless, an extensive variety of lubricants encompasses the following functions.

• Cleaning and sweep away the debris and contaminations
• Protect against corrosion
• Reduce friction and wear
• Reduce vibrations and noise
• Seals for gases
• Separate interacting surfaces
• To dissipate heat
• Transfer of power

9.1.2 Classification of Lubricants

The lubricants are chiefly categorized in conformity with their (a) physical state, (b) origin of base oil and (c) applications (Mobarak et al., 2014). Figure 9.1 shows the classification of lubricants. By their physical state, the lubricants are further categorized as solid, semi-solid and liquid. In some exceptional cases, gases are als...