The reliability of industrial equipment, transportation systems, nuclear and conventional power plants etc. can be significantly influenced by surface phenomena such as corrosion and wear. With the increasing pressure on development time and the need for higher performance, there is also an increasing need to measure and quantify the degradation phenomena faster and better. In this perspective, nuclear activation technology - as already used in engine testing- can provide accurate in-situ measurement and precise monitoring of wear, mass transfer, corrosion and erosion.
In the effort to reduce CO2 exhaust, an important approach is to reduce friction in the engine. One part of the mix of options are ‘friction modifying additives’, such as the well-known GMO, which are known to reduce friction by 5, 10 or 20%. However, the difficult task is to prove the effect of friction modifiers in the engine, since existing engine tests measure the interaction of all sliding and moving components, as well as lubricant viscosity and other effects. In order to isolate and evaluate the efficiency of friction modifiers, a precision frictional approach is required.
The steering system of cars is based on a rack and pinion system. Over time, the metal on these gears wears out, resulting in a loose fitting. Some other applications also make use of a rack and pinion system to translate a rotary drive motion into a linear displacement. The wear and tear of such systems occurs through a roll-slip mechanism. Therefore a tribological method needs to be developed to simulate such roll-slip contacts and their failure mechanisms.
During the processing of bricks in the construction industry, clays slurries can adhere (stick) to mechanical components such as mixers, hindering their function. In addition, in the drilling industry severe damage of the drills can be caused by the sticking and swelling (due to water adsorption) of soils onto the drills. A methodology needs to be developed to measure the stickiness of clays/soils on metallic components.
WHY ? : Abrasion and erosion mechanisms are quite different from each other, and can lead to very different material behaviour. For instance, a hard and brittle surface may be very resistant to abrasion, but sensitive to erosion under 90° impact.
One of the most difficult industrial issues related to tribology is the prediction of long term wear or material durability. In many components and products, materials with or without lubrication are used to reduce wear and maintain functionality of the component. Required ‘wear life’ may be thousands of hours. Contrary to the determination of a ‘coefficient of friction’ – which can be done in a few hours, the determination of wear and wear rate under realistic conditions is a long term test. The challenge is twofold : perform low wear rate experiments with many repeats at an economically acceptable cost. The only way to do this is by a multistation approach (performing many wear experiments simultaneously).
Parallel tests were performed in our TRL6 prototype 10-station cross-cylinder block-on-cylinder tester. With this method, we test parallel and simultaneously different bulk or coated materials (metals, alloys, polymers, ceramics and composites), at moderate contact pressures and for a prolonged period of time. Adhesive or mild abrasive wear mechanisms are representative for the “actual” applications.
Up to 9 kilometers of sliding distance can be realised in a single day, on 10 wear contacts simultaneously.
To measure the wear damage, we use weight loss measurements, optical and/or confocal microscopy. 10 data points collected efficiently
Efficient screening showed
The wear of various materials can be measured in a time efficient and economical way, realistic wear rates simulate actual applications.
Statistical analysis of the wear data provides a higher confidence level and allows outlier analysis.
Reliability testing of materials becomes economically possible.
High temperature tribological testing often requires the development of complex mechanical setups, that should meet rigorous standards and specific performance metrics. Thus, the development of a state-of-the-art experimental setup to study the reciprocating sliding behaviour of various bulk and coated materials at temperatures that can reach up to 1000 °C is needed, especially for the evaluation of high temperature materials for aeronautical applications.
One of the main issues in the watch industry is reduce the friction and sticking between moving components. To achieve this, a small quantity of lubricant is added in the contact. However, due to the high expectations of the costumers, the increased lifetime of the watch, the size and geometry of components and contact conditions (loads in the mN range), there is a huge need to develop a tool that can evaluate such lubricating tribo-systems. The main challenge is to perform precision frictional measurements, in conditions that simulate the “actual” application.
Take advantage of the use of nano-particles for production of composite coatings with superior properties compared to those of hard chromium produced by electroplating or to WC-Co produced by thermal spray.
Surgical suture, holding body tissue together after an injury or surgery, is a complex product. The thread can be surface treated or coated for a number of reasons. One of them is to facilitate the insertion through tissue, the other to hold the knots tightly. Friction of the suture over skin, is thus important to control. Measuring skin-suture friction allows improvement of these threads and their surface treatment.