Unravelling Solid Self-Lubrication Mechanisms of Boron Oxide

Transition metal borides (TMBs) are an exciting group of materials with significant potential for creating highly durable coatings. These ceramic materials are not only cost-effective and abundant but also show remarkable resistance to wear, heat, and corrosion. A particularly fascinating aspect of TMBs is their ability to "self-lubricate," meaning they can minimize friction by forming specialized solid oxide layers on their surfaces, thus eliminating the need for additional liquid lubricants such as oils or greases. This is especially important in extreme environments, where liquid lubricants cannot be used, i.e. at high temperatures or vacuum. The precise mechanisms that drive this solid self-lubrication, especially in TMB based thin films, remain largely unexplored. This project seeks to investigate the conditions under which boron oxides (B2O3) form on TMB surfaces and how these formations affect lubrication performance. The study will consider various external factors, including temperature, humidity, air composition, and the specific chemical makeup of the coatings. To analyze these dynamics, our team employs advanced coating technologies, particularly Physical Vapor Deposition (PVD), and in-situ monitoring tools that allow direct observation of these solid lubricants based on B2O3 during testing. Techniques such as X-ray diffraction, scanning and transmission electron microscopy, or synchrotron beam line experiments will provide valuable insights into how the targeted B2O3 structures evolve and how these changes influence friction behavior. The primary objective of this research is to deepen our understanding of boron oxides` fundamental behavior in tribological contacts using TMB coatings. For the study well-known model systems such as TiB2 or WB2 will be used. The insights gained could lead to the development of innovative materials capable of functioning reliably in extreme environments, such as aerospace, high-performance engines, or industrial machinery, without relying on traditional liquid lubricants. This study aims to unlock new possibilities in materials science, enhancing the performance and longevity of coatings in demanding applications while contributing to cost-effective and sustainable engineering solutions.