The Twelve Principles of Green Tribology: Studies, Research, and Case Studies—A Brief Anthology

Abstract

Sustainability has become of paramount importance, as evidenced by the increasing number of norms and regulations concerning various sectors. Due to its intrinsic trans-sectorial nature, tribology has drawn the attention of the supporters of sustainability. This discipline allows the environmental, economic, and social impacts to be decreased in a wide range of applications following the same strategies. In 2010, Nosonovsky and Bhushan drew up 12 approaches based on the 12 principles of green chemistry and the 12 principles of green engineering, defining the “12 principles of green tribology.” This review exploits the 12 principles of green tribology to fathom the developed research related to sustainability and tribology. Different approaches and innovative studies have been proposed in this short selection as references to consider for further development, pursuing the efforts of the scientific community for a sustainable future through the contribution also of tribosystems. The manuscript aims to provide practical examples of materials, lubricants, strategies, and technologies that have contributed to the overall progress of tribology, decreasing wear and friction and increasing efficiency, and at the same time promoting sustainable development, lowering toxicity, waste production, and loss of energy and resources.

Areas of green tribology: A review

“…Green tribology can utilise the goals of green chemistry. The twelve goals of green tribology are as follows [6]:…”

“…The following three tribology areas are crucial for green tribology since they have a significant influence on environmental issues: tribology of biomimetic materials and surfaces, biodegradable and environmentally friendly lubricants, and renewable and/or sustainable sources of energy [6][7][8][9]. The current situation of these places and their importance for the emerging science of green tribology are briefly discussed below.…”

Test bench development and implementation for experimental determination of mechanical losses in single cylinder internal combustion engines

“…The effective voltage (v o ) which supplies the electrical resistor (R) is equivalent to the product between the square root of duty cycle (η) and the voltage provided by the generator (v s ), (2). The demanded current by the resistor (i) is equal to the product of the square root of (η) and the current that would be drawn by the electrical resistor if it were directly connected to the generator (i max ), (3).…”

“…Due to the technological evolution of internal combustion engines (ICE) and the variety of designs, geometries, materials and surface treatments of components, lubricants, additives and fuels used to improve the engine performance, it is necessary to have test stations to identify the different operating characteristics of ICE and evaluate the effects that the different technological alternatives have on the effective, indicated or mechanical performance [1,2].…”

Fundamental Structure–Function Relationships in Vegetable Oil-Based Lubricants: A Critical Review

“…They also have lubrication advantages over mineral oil such as low volatility, better lubricity, winder viscosity ranges and higher viscosity index, flash point, and higher solubilizing capacity for additives [30,31]. On the contrary, biobased lubricant molecules also have inherent weaknesses, including susceptibility to chemical reactions, particularly in ester and alkene groups, crystallize at sub-zero temperatures, have susceptibility to thermo-oxidative degradation particularly at temperatures > 250 • C, and are more expensive compared to mineral oil [32]. A list of the environmental, performance, properties, and economic advantages and disadvantages of VOs and VO-based lubricants [14,31,[33][34][35][36][37][38] is provided in Table 4.…”