Accessing Inaccessible Interfaces: In Situ Approaches to Materials Tribology

Abstract

The field of materials tribology has entered a phase of instrumentation and measurement that involves accessing and following the detailed chemical, structural, and physical interactions that govern friction and wear. Fundamental tribological research involves the development of new experimental methods capable of monitoring phenomena that occur within the life of a sliding contact. Measuring friction phenomena while the process is ongoing is a major improvement over earlier techniques that required the surfaces to be separated and analyzed, thereby interrupting the frictioncausing event and modifying surface conditions. In the past, MRS Bulletin has highlighted how in situ approaches can greatly enhance our understanding of materials structure, processing, and performance. This issue highlights in situ approaches as applied to materials tribology, namely, the study of contacting surfaces and interfaces in relative motion.

In Situ Attenuated Total Reflection (ATR/FT-IR) Tribometry: A Powerful Tool for Investigating Tribochemistry at the Lubricant–Substrate Interface

“…The partial derivatives (Eqs. [2][3][4][5] have to be evaluated at the nominal values of the input quantities.…”

“…In situ methods allow the direct probing of materials mechanics and chemistry characterizing the buried sliding interface as they form, in their ''natural state'' [1,3]. The power of in situ studies in tribology has been recently highlighted in an issue of the MRS Bulletin, completely dedicated to the topic [3].…”

A simple, fast and low-cost method for in situ monitoring of topographical changes and wear rate of a complex tribo-system under mixed lubrication

“…Some studies [1,[6][7][8][9][10] have already highlighted the importance of measuring the wear rate continuously and in situ during the process. However, in most studies, the tribo-system is simplified to allow in situ measurements [7,8]. Such simplifications are ideal to investigate the fundamental behaviour of a given tribo-pair from a material perspective.…”

Formation and Oxidation of Linear Carbon Chains and Their Role in the Wear of Carbon Materials

“…Insights into such processes are notoriously difficult to obtain, simply because the area of interest is buried between two surfaces, and hence not easily accessible with experimental analytical tools. Rare exceptions are recent efforts to study wear and friction of partially transparent materials [4]. Still, clean wear experiments along the lines of very clean friction experiments that have been carried out recently [5,6] are difficult, since wear is one fundamental source of the ''dirt'' that is eliminated in atomic scale friction experiments.…”