Tribology
Tribology explores the complex interaction of surfaces in motion with the objective of understanding friction and minimising wear. This interdisciplinary field combines principles from mechanical engineering, materials science and chemistry to improve the efficiency of machines.
Table of contents
- What is tribology?
- Determining the coefficient of friction & inspecting wear at Quality Analysis
- Why are tribological inspections important?
- The three areas of tribology – wear, friction and lubrication
- What affects friction and wear?
- Measurement methods for tribology
- Applications for tribology
- Tribology in summary
What is tribology?
Tribology is a specialist area relating to the science and technology of interactions involving friction between surfaces in relative motion. The central areas addressed by tribology are friction, wear and lubrication. They directly affect the efficiency and reliability of technical systems due to changes in geometry, the formation of wear particles, as well as the production of heat and noise. Tribology attempts to find ways to understand and minimise these effects and to create optimal operating conditions.
Determining the coefficient of friction & inspecting wear
at Quality Analysis
By analysing wear patterns and friction characteristics, the causes of material failure can be identified and future damage prevented. For this purpose, our experts at Quality Analysis identify wear mechanisms with the aid of all the necessary microscopic methods to provide you with information about the measures required to rectify problems quickly.
- 3D characterisation of the surface using laser scanning microscopy
- Scanning electron microscopy (SEM) for detailed analysis of the surface morphology
- Non-destructive inspection and three-dimensional depiction using industrial computed tomography
- Systematic damage analysis for the identification of the cause of the damage
Why are tribological inspections important?
By understanding tribological characteristics, it is possible to detect potential problems at an early stage, identify the causes of wear and friction and develop measures to optimise lubrication. In this way the service life of components can be extended, failures reduced and the efficiency of machines and systems increased. Tribological inspections help to advance the development of more robust products that meet requirements in various sectors and also contribute to the improvement of the quality, reliability and cost-effectiveness of products and processes.
Tribology und material inspection:
optimisation of materials and machine elements
Tribology is closely linked to material inspection (materialography) – the disciplines complement each other during the analysis of the performance and functionality of materials and machine elements. While during material inspection, the emphasis is on the analysis of the characteristics and the behaviour of materials in varying conditions, tribology is focussed on understanding and optimising the interaction between surfaces in motion.
The three areas of tribology – wear, friction and lubrication
Tribology involves three central areas: wear, friction and lubrication. It is important to emphasise that findings and solutions cannot be simply transferred from one system to another in tribology. The tribological behaviour of materials must be assessed individually for specific applications, often with the aid of tests involving models and simulations. Only in this way can the test conditions be adapted to the actual operating conditions and effective solutions developed.
hat is wear?
Wear is the term used for the loss of material that occurs due to friction between interacting surfaces. As a rule, it is the result of various parameters that interact, for instance friction, the characteristics of the materials, ambient conditions, temperature, as well as physical and chemical action. A differentiation is made between adhesive wear, abrasive wear and fatigue wear.
Wear inspection
The identification and analysis of wear mechanisms is of crucial importance for preventing material failure and extending the service life of components. Methods for wear analysis include the analysis of wear patterns, the identification of wear mechanisms using microscopic methods and the evaluation of wear resistance. In addition, there are numerous application-specific test methods for characterising material characteristics such as hardness, friction, corrosion or fatigue behaviour.
Friction and the coefficient of frictiont
Friction describes the force that acts between two surfaces. Both technical factors (e.g. geometric shape, deformation and the condition of the interfaces) as well as external factors (load, speed, temperature, atmosphere, etc.) affect friction and wear. Tribological inspections for friction therefore also include the topography of the surface, as well as the inspection of the surface roughness; this information permits differentiation between actual contact surfaces and nominal contact surfaces. Here all cavities that could play a role in the friction behaviour are taken into account.
Friction force and normal load
The resistance between two moving objects consists of a linear relationship between the friction force and the normal load applied. The coefficient of friction, which describes the relationship between these forces, is a crucial parameter for the friction behaviour. The measurement and evaluation of the coefficient of friction as well as the analysis of friction characteristics are crucial for the optimisation of machines and the reduction of energy losses. Methods such as the determination of the coefficient of friction and measurement of the surface characteristics make it possible to characterise the friction behaviour in varying conditions.
Lubrication – optimising friction and wear
Lubrication plays a crucial role in the minimisation of friction and wear by forming a lubricant film between the surfaces. Analyses include the detailed analysis of the surface morphology using scanning electron microscopy (SEM) as well as the evaluation of lubricants and lubrication systems in real operating conditions. By optimising the lubrication, it is possible to improve the performance and service life of machines and components.
What affects friction and wear?
Friction and wear in tribological systems are affected by numerous factors that go beyond the pure material characteristics. Important factors include the geometry of the contact surfaces, the viscosity and the characteristics of the lubricant, the speed at which the surfaces move in relation to each other, as well as specific ambient conditions such as temperature and humidity. System-related load parameters such as the surface pressure and the relative speed of the movement of the two contact surfaces play a crucial role.
Measurement methods for tribology
The measurement of tribological phenomena requires numerous tools and methods to be able to characterise the interactions between two surfaces in motion. A key technique is scanning electron microscopy (SEM), which makes it possible to analyse surface structures at the microscopic level and to make visible signs of wear as well as other tribological features. By means of SEM, it is also possible to undertake detailed analyses of the surface morphology to identify the causes of wear and friction.
Methods for tribological measurement
In addition, tribological measurement methods also include methods such as damage analysis, during which the wear pattern and signs of wear on material surfaces are analysed to draw conclusions as to the nature and the mechanism of the wear. This analysis can also provide information about how materials react to certain loads and conditions as well as which measures can be taken to prevent damage.
Applications for tribology
Automotive
In the automotive industry, knowledge from tribology contributes to the optimisation of engines, gearboxes, brakes and other moving parts. By means of the improvement of friction characteristics and wear resistance, the performance, efficiency and durability of vehicles can be increased. For example, tribological coatings on engine parts can reduce friction and lower fuel consumption.
Aerospace
In aerospace, tribology is crucial for the development of lubricants and materials that can withstand the extreme conditions in space. Tribological tests and analyses are indispensable for ensuring the reliability and performance of components such as bearings, seals and engines. As such, tribological coatings on aircraft parts must withstand particularly high temperatures and loads.
Medical technology
In medical technology, tribology plays an important role during the development of implants and medical devices. Particularly for joint implants such as artificial hip joints, tribology is crucial for minimising wear and optimising mobility. Tribologically optimised hip implants can increase the service life of the implant and reduce patient pain.
Electronics manufacturing
In electronics manufacturing, tribology plays a role during the manufacture of precision components and microcomponents. The tribological characterisation of surfaces and the optimisation of manufacturing processes are paramount for the quality and reliability of electronic devices. For example, tribological coatings on printed circuit boards can reduce friction and increase the service life of devices.
Tribology in summary
Tribology, as an interdisciplinary specialist area, researches the interactions between surfaces in motion to understand friction, minimise wear and optimise lubrication. With its mixture of mechanical engineering, materials science and chemistry, tribology aims to improve the efficiency and reliability of machines. Quality assurance, in particular by means of the analysis of wear patterns and friction characteristics, plays a central role in tribology to prevent material failure and to extend the service life of components.
