The recent rise of 2D materials has extended the opportunities of tuning a variety of properties. Tribo-corrosion, the complex synergy between mechanical wear and chemical corrosion, poses significant challenges across numerous industries where materials are subjected to both tribological stressing and corrosive environments. This intricate interplay often leads to accelerated material degradation and failure. This review critically assesses the current state of utilizing 2D nanomaterials to enhance tribo-corrosion and -oxidation behavior. The paper summarizes the fundamental knowledge about tribo-corrosion and -oxidation mechanisms before assessing the key contributions of 2D materials, including graphene, transition metal chalcogenides, hexagonal boron nitride, MXenes, and black phosphorous, regarding the resulting friction and wear behavior. The protective roles of these nanomaterials against corrosion and oxidation are investigated, highlighting their potential in mitigating material degradation. Furthermore, we delve into the nuanced interplay between mechanical and corrosive factors in the specific application of 2D materials for tribo-corrosion and -oxidation protection. The synthesis of key findings underscores the advancements achieved through integrating 2D nanomaterials. An outlook for future research directions is provided, identifying unexplored avenues, and proposing strategies to propel the field forward. This analysis aims at guiding future investigations and developments at the dynamic intersection of 2D nanomaterials, tribo-corrosion, and -oxidation protection.

The rising global life expectancy has underlined the necessity of designing novel and tasty food products, suitable for seniors and people with impaired oral and swallowing functions. For developing these products, texture should be optimised from rheological, colloidal, tribological, and masticatory points of view. The current review provides an overview of different studies based on shear rheological, tribological, and in vitro mastication properties of model or real food systems intended for the elderly and/or people with swallowing dysfunctions, with special emphasis on the relation between the instrumental measurements and sensory perceptions of foods. Several works demonstrated that instrumental data from shear rheological and tribological tests complement the sensory evaluations of foods, providing useful information when designing food commodities for specific populations. Conversely, only few works correlated the instrumental data obtained from artificial mouths and/or simulated masticators with the sensory attributes generated by trained assessors. Broaden knowledge of these topics will help in formulating and adapting foods with enhanced functionalities for people with impaired oral and swallowing capabilities. Shear rheology, soft oral tribology, and simulated mastication tests are crucial in designing safe- and easy-swallowing food products.

Biocomposites have gained huge attention in the field of manufacturing. They are widely accepted over conventional petroleum-based composites due to less environmental footprint and safer living habitats, abundance, availability, recyclability, reusability, and end-life disposals. The potential applications of biocomposites are now widely accepted in key engineering areas such as automotive, construction, consumer products, and aerospace industries. Concurrently, tribological properties for biopolymer composites are an appealing research direction. In this review article, a comprehensive literature survey of recent progress made in sliding wear properties of biocomposites are discussed in detail. It summarizes natural and synthetic ways to attain tribological performances in biocomposites such as biopolymers with bio-fillers, biopolymers with synthetic/inorganic fillers, and non-biopolymers with bio-fillers. The study gives a deeper understanding of the crucial informations regarding sliding wear properties of biocomposites and thereby aid in the future research in the design and preparation of similar composites.

OBJECTIVE: From the treatment of damaged teeth to replacing missing teeth, dental biomaterials cover the scientific interest of many fields. Dental biomaterials are one of the implants whose effective life depends vastly on their material and manufacturing techniques. The purpose of this review is to summarize the important aspects for metallic dental implants from biomedical, mechanical and materials science perspectives. The review article will focus on five major aspects as mentioned below. Tooth anatomy: Maximizing the implant performance depends on proper understanding of human tooth anatomy and the failure behavior of the implants. Major parts from tooth anatomy including saliva characteristics are explored in this section. Wear mechanisms: The prominent wear mechanisms having a high impact on dental wear are abrasive, adhesive, fatigue and corrosion wear. To imitate the physiological working condition of dental implants, reports on the broad range of mastication force and various composition of artificial saliva have been included in this section, which can affect the tribo-corrosion behavior of dental implants. Dental implants classifications: The review paper includes a dedicated discussion on major dental implants types and their details for better understanding their applicability and characteristics. Implant materials: As of today, the most established dental implant materials are SS316L, cobalt chrome alloy and titanium. Detailed discussion on their material properties, microstructures, phase transformations and chemical compositions have been discussed here. Manufacturing techniques: In terms of different production methods, the lost wax casting method as traditional manufacturing is considered. Selective Laser Melting (SLM) and Directed Energy Deposition (DED) as additive manufacturing techniques (AM) have been discussed. For AM, the relationships between process-property-performance details have been explored briefly. The effectiveness of different manufacturing techniques was compared based on porosity distribution, mechanical and biomechanical properties.
CONCLUSIONS: Despite having substantial research available on dental implants, there is a lack of systematic reviews to present a holistic viewpoint combining state-of-the-art from biomedical, mechanical, materials science and manufacturing perspectives. This review article attempts to combine a wide variety of analyzing approaches from those interdisciplinary fields to deliver deeper insights to researchers both in academia and industry to develop next-generation dental implants.

Tribology is the discipline concerning the application of friction, lubrication, and wear concepts of interacting surfaces in relative motion. A growing interest has developed in tribology application in medical biomaterials, such as resin composites used in restorative dentistry. Yet, the keywords \"tribology\" and \"biotribology\" are little applied in the pertinent publications. The aim of this scoping review was to offer an overview of tribology application in dental composites research and to identify knowledge gaps and address future research. A literature search was conducted on Pubmed and Scopus databases and the studies investigating the tribological behavior of resin composites were included for qualitative synthesis. The majority of studies on dental tribology were published in the research areas of mechanical engineering/nanotechnology and differed in several methodological aspects. The preponderant engineering approach and the lack of standardized testing make the laboratory findings poorly informative for clinicians. Future research should focus on the tribological behavior of dental materials composites by means of an integrated approach, i.e., engineering and clinical, for improving development and advancement in this field of research.

Transition metal carbides, nitrides and carbonitrides (MXenes) have recently attracted notable attention in tribology and, particularly solid lubrication, due to their low shear strength and ability to form low-friction, wear-resistant tribo-layers. Their use as lubricant additives has only shown limited success due to their inherent hydrophilic character, causing a low phase-compatibility and dispersion-stability with pure base oils. To overcome this shortcoming and to boost MXenes\' tribological performance as lubricant additive and reinforcement phase in composites, their tuneable surface chemistry moves into the focus of current research. Originating from chemical etching to synthesize MXenes, their outer surface contains a variety of surface terminations, which can function as anchoring points for molecules via covalent grafting/functionalization. By adopting an adequate functionalization strategy, this, in turn, can help to tailor MXenes\' hydrophobicity, dispersion stability, restacking tendency, or oxidation resistance. This directly affects their dispersion stability in base oils and improves their phase compatibility with other matrix materials in composites, thus resulting in an enhanced tribological performance. Therefore, this review concisely summarizes the existing state-of-the-art regarding MXenes\' covalent functionalization with a particular emphasis on tribological properties and needs, a topic, which has not been holistically reviewed yet. The first chapter sheds light on the existing synthesis approaches with detailed insights regarding the resulting surface terminations, which are crucial for the subsequent chemical functionalization. After summarizing strategies to increase their interlayer distance to improve the accessibility for chemical functionalization and the existing state-of-the art regarding MXene tribology, we critically discuss the existing functionalization strategies using different coupling agents (organosilanes, organophosphorus agents, aryldiazonium agents, among others). Subsequently, we emphasize on the crucial role of homogeneously distributed -OH surface terminations to guarantee the overall success of the functionalization approach and to boost the resulting tribological performance. Lastly, we address the existing challenges and derive future research directions. We anticipate that our article can serve as an excellent guide for MXenes\' chemical functionalization, which can be useful in various applications including tribology thus paving the way towards enhanced physical and chemical properties of MXenes.

Friction and wear usually lead to huge energy loss and failure of machine pairs, which usually causes great economic losses. Researchers have made great efforts to reduce energy dissipation and enhance durability through advanced lubrication technologies. Single-layer coatings have been applied in many sectors of engineering, but the performance of single-layer coatings still has many limitations. One solution to overcome these limitations is to use a multilayer coating that combines different components with varied physical and chemical properties. In addition, multilayer coating with alternating layers only containing two components can lead to improved performance compared to a coating with only two different layers. This paper systematically reviews the design concept and properties of different types of multilayer coatings, including transition-metal nitride coatings, diamond-like carbon-based coatings, and other multilayer coatings. The inherent functional mechanisms of the multilayer structures are also detailed and discussed.

Corrosion and tribology are surface phenomena. Modifying surfaces of materials without resorting to altering their bulk properties is an effective route to alleviate corrosion, friction and wear, encountered in engineering applications. With the advancements in the field of nanotechnology, surface protective coatings with nanomaterials can be readily developed to explore their functionality in mitigating chemical/physical damage of surfaces. Surface protection enhances performance and operating lifetimes of industrial machinery components. This review presents insights on various types of recently developed nanostructured coatings, their synthesis routes, corrosion behaviour and tribological performance. It provides the state-of-the-art information on the development of nanostructured coatings, namely, ceramic coatings, metallic coatings and nanocomposite coatings with metal and polymer matrices. Biomimetic approaches in making nanostructured coatings and challenges encountered in the development of nanostructured coatings are highlighted.

Understanding the complex nature of wear behavior of materials at high-temperature is of fundamental importance for several engineering applications, including metal processing (cutting, forming, forging), internal combustion engines, etc. At high temperatures (up to 1000 °C), the material removal is majorly governed by the changes in surface reactivity and wear mechanisms. The use of lubricants to minimize friction, wear and flash temperature to prevent seizing is a common approach in engine tribology. However, the degradation of conventional liquid-based lubricants at temperatures beyond 300 °C, in addition to its harmful effects on human and environmental health, is deeply concerning. Solid lubricants are a group of compounds exploiting the benefit of wear diminishing mechanisms over a wide range of operating temperatures. The materials incorporated with solid lubricants are herein called \'self-lubricating\' materials. Moreover, the possibility to omit the use of conventional liquid-based lubricants is perceived. The objective of the present paper is to review the current state-of-the-art in solid-lubricating materials operating under dry wear conditions. By opening with a brief summary of the understanding of solid lubrication at a high temperature, the article initially describes the recent developments in the field. The mechanisms of formation and the nature of tribo-films (or layers) during high-temperature wear are discussed in detail. The trends and ways of further development of the solid-lubricating materials and their future evolutions are identified.

It has been established in literature that the addition of nanoparticles to lubricants at an optimum concentration results in a lower coefficient of friction compared to lubricants with no nanoparticle additives. This review paper shows a comparison of different lubricants based on the COF (coefficient of friction) with nanoadditives. The effect of the addition of nanoparticles on the friction coefficient was analyzed for both synthetic and biolubricants separately. The limitations associated with the use of nanoparticles are explained. The mechanisms responsible for a reduction in friction when nanoparticles are used as an additive are also discussed. Various nanoparticles that have been most widely used in recent years showed good performance within lubricants, including CuO (copper oxide), MoS2 (molybdenum disulfide), and TiO2 (titanium dioxide). The paper also indicates some research gaps that need to be addressed.