Bearings are versatile machine components –they are found in a wide variety of environments, some of which contain high amounts of hydrogen. With the transition to a greener economy, it is time to revisit applications where hydrogen is a critical constituentin the environment. One product segment of particular interest is pumps and compressors, which have to be designed to operate to pressures...
Tribocorrosion of hydrogen-embrittled steel is a critical concern for materials used mostly in harsh environments, particularly in applications involving high mechanical stress and corrosive conditions. Hydrogen uptake by steel structures, induced by an electrochemical process, can cause degradation of mechanical properties and induce cracks. It is widely known as hydrogen embrittlement....
It has been established that hydrogen diffusion can significantly influence the mechanical response of metallic materials under various loading conditions. This phenomenon is particularly evident in reducing the ability for plastic deformation. The formation and collapse of bubbles inside a fluid, i.e., cavitation near a solid surface generates one of the most complex loading scenarios. The...
Low-speed two-stroke engines have powered marine transportation for over a century and remain the standard propulsion system for marine transport due to their high efficiency and reliability. Today, as the maritime industry aims to reduce greenhouse gas (GHG) emissions to zero by about mid of the century, technological innovation is key to achieving a sustainable future.
As a leading...
The global transition to renewable energy depends heavily on the utilization of hydrogen. Since hydrogen is of low density and gaseous, it must be compressed to pressures exceeding 500 bar to achieve practical energy density for efficient storage and transport. This demands compressors with long service life and high efficiency. To achieve this, reciprocating piston compressors rely on...
The development of robust preclinical evaluation techniques for orthopaedic implants is critical in light of recent high-profile implant failures and the increasing regulatory demands of EU MDR and FDA guidelines. This study introduces a novel framework integrating real-time wear-corrosion and wear debris analysis techniques for the comprehensive assessment of implant degradation...
Framatome designs and manufactures pressurized water reactors. In 2023, 63% of electricity produced in France comes from nuclear reactors. Within the reactor, some components are subjected to wear, due to fluid excitation, and to movements of rods used to adapt the reactor’s power.
The working environment of these components is pressurized water at high temperature with a dedicated...
Tribocorrosion research have greatly advanced our understanding of the interplay between wear and corrosion in different materials. While considerable progress has been made in elucidating the tribocorrosion responses of passive alloys such as stainless steels, the combined effects of corrosion and mechanical wear in active steels remain less explored.
In this work, the tribo-electrochemical...
The aim of our study was to evaluate the tribo-corrosion properties of different grades of high-speed steels subjected to different heat treatment strategies. Conventionally heat-treated steel grades were compared to un-conventionally treated comprising cryogenic treatment cycle in order to investigate the effect of chemical composition, microstructure and hardness of the material on...
Gold is considered a noble metal due to its chemical inertness and resistance to oxide formation within the stability potential window of water. However, gold is very soft, and it is commonly alloyed with other metals (copper, silver, zinc) to improve its mechanical properties. The use of less noble alloying elements such as copper or silver, may lead to a preferential dissolution of those...
Tribochemical processes occur in various environments, where the combination of mechanical stress and chemical reactions can lead to significant changes in material properties, surface composition, roughness and technological performance. A detailed observation of chemical and mechanical tribodegradation, as well as materials repassivation are difficult to asses in-situ. Our main objectives in...
CoCrMo alloys have been widely used as implant materials due to their excellent combination of mechanical strength, corrosion resistance and biocompatibility. However, the release of wear debris during service can trigger inflammatory responses in peri-implant tissues, while reactive oxygen species (ROS) generated by the immune response to bacterial infections may alter surface chemistry and...
Spinal implants, especially modular systems like bilateral instrumentation constructs, are susceptible to fretting corrosion due to micro-motion at interfaces. This study presents a novel combined biomechanical and electrochemical testing setup for pre-clinical assessment, enabling evaluation under sequential and physiological load conditions. The investigation included bilateral spinal...
INTRODUCTION: Cobalt-Chromium (CoCr) alloy is a common material for hemiarthroplasty. In this scenario only one side of the diseased joint is replaced, thus that the opposing cartilage articulates against the prosthetic device. Hemiarthroplasty is a promising treatment option for mild joint degeneration, offering the benefits of bone preservation and reduced operative time. However, in vitro...
One persistent issue that plagues carbon abatement and energy sectors is infrastructure degradation through corrosion. Currently, the most popular method of internal corrosion control for carbon steel infrastructure consists of the application of corrosion inhibitors which suppress corrosion through surface adsorption. This technology is well-established, being relied upon in both traditional...
Tribocorrosion in CO2 in anoxic environments remains poorly understood, despite its relevance in critical sectors such as oil and gas, geothermal energy, and carbon capture and storage (CCS). While CO2 corrosion mechanisms of metals have been widely researched over the past decades, the additional influence of sliding motion on surface degradation and tribocorrosion wear has received limited...
Erosion-corrosion performance of nickel
aluminium bronze alloys in marine environments: recent developments
Robert JK Wood and Julian A Wharton
National Centre for Advanced Tribology at Southampton (nCATS), Department of Mechanical Engineering, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, SO17 1BJ, UK.
Abstract
Nickel Aluminium...
Tribocorrosion often occurs in conjunction with fatigue in engineering applications, leading to a material multidegradation phenomenon. This interaction has been extensively investigated, particularly within the oil and gas industry, where different grades of stainless steels have been tested under diverse tribocorrosion-fatigue conditions. The underlying mechanisms governing the interaction...
Tribometry involves numerous testing configurations in which parameters such as geometry, pressure, speed, and temperature are modified to replicate real tribological conditions as closely as possible. Although the outcomes are often difficult to predict, tribological testing methods are well established. Similarly, corrosion testing setups combined with instrumentation for electrochemical...
Pressurized gas environments are critical in industries such as aerospace, energy, and manufacturing, where the behavior of materials and lubricants under high-pressure conditions can significantly influence system efficiency, safety, and durability. However, traditional tribological testing methods often fail to replicate the complex conditions encountered in these environments. To address...
The rapid growth of electric mobility introduces unique challenges for lubricants, distinct from those in internal combustion engines. Key requirements include electrical compatibility to prevent short circuits, superior thermal managementto handle heat generated by batteries and motors, and material compatibility with plastics and seals. Lubricants must also address noise, vibration, and...
The study investigated a water-based lubricant specifically designed for power tools, such as diamond drilling tools used in the construction industry. The water content in the lubricant enhances heat transfer capabilities and provides superlubricity, thereby improving thermal management and gearbox efficiency during operation. The formulation was evaluated using standardized ASTM laboratory...
White etching crack (WEC) is a subsurface cracking reported to have occurred in many applications including automotive (alternator bearings), wind turbines (WTs) (gearbox bearings), oil and gas refineries (compressors bearings), and many others. Although this problem has been studied extensively over the past many years, there is still a debate on the underlying mechanisms. Lubricant additives...
In this study, friction and wear of conventional and alternative high performance polymer compounds for compressors were investigated in gaseous hydrogen and nitrogen up to 80 bar of gas pressure. The compounds used were a commercial PEEK matrix with 10 wt.% each of PTFE, graphite, and short carbon fibres (Polytron), a PPS matrix with 10 wt.% each of PTFE and graphite (MOCOM), and an...
The deployment of hydrogen as a sustainable alternative to fossil fuels demands the use of materials that can ensure safety, durability, and performance across a range of operating conditions. Thermoplastic polymers are increasingly used in hydrogen infrastructure and components due to their chemical stability, low weight, and processability. However, their tribological performance...
The aim of our study is to evaluate the tribo-corrosion properties of conversion coatings on Vanadis 6 type of steel. Vanadis 6 cold work steel is a high-carbon, high alloyed steel known for its favourable mechanical properties even in very harsh operating conditions, including high loads, contact stresses, contact temperatures and severe wear [1]. Mechanical properties were recently reported...
KEYWORDS: Coatings, Molybdenum nitride, Physical vapour deposition, Ti-6Al-4V alloy, Tribocorrosion, Magnetron sputtering
INTRODUCTION
Driven by factors such as sedentary lifestyles and age-related degeneration, the increasing prevalence of musculoskeletal disorders has heightened the need for innovative orthopaedic solutions [1]. Biomedical alloys, meticulously designed to operate...