Application Examples

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Cost efficient data collection for statistical analysis of wear - TRL 6

WHY ?  : 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). 

HOW ?  : 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

 

b2ap3_thumbnail_10-station Applications   

 

RESULT :

  • 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.

b2ap3_thumbnail_10-station_ranking-polymers Applications

 

 

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Simulation of wear in roll-slip contacts

WHY ?  : 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.

HOW ?  : A modification on the Falex Multispecimen machine allows for a 2-rollers on disk geometry. During each turn these rollers rotate and slide simultaneously, simulating a roll-slip contact. The speed and load can be adjusted to achieve similar contact conditions as in the actual application. The contact can be either dry or lubricating, whereas the rollers and/or disks can be bare or coated materials. In this application series we investigated the use of coatings to decrease the friction and wear of the tribo-system, whereas the contamination of lubricant with hard particles (e.g. sand) was also taken into consideration.   

b2ap3_thumbnail_Falex-Multispecimen alloys - Application examples | FACTLABS.ORG 

 

RESULT :

- A roll-slip contact can be simulated by a Falex Multispecimen tester.

- Coatings can improve the wear resistance and frictional performance of roll-slip contacts.

- The presence of hard particles is a major risk for degrading the performance of a lubricant in roll-slip contacts.

b2ap3_thumbnail_Effect-of-coating-on-COF alloys - Application examples | FACTLABS.ORG

b2ap3_thumbnail_effect-of-sand-on-wear-evolution_roll-slip alloys - Application examples | FACTLABS.ORG b2ap3_thumbnail_effect-of-sand-on-roll-slip-wear alloys - Application examples | FACTLABS.ORG

 

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