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Prescreening the ISO20763 & ASTM D7043 Vickers Vane Pump tests

WHY

The standard method for evaluating anti-wear of hydraulic fluids in a vane pump, is by the 100 hour ASTM or 250 hour ISO method, using a real Conestoga-built vane pump.  This method takes a long time to run, and requires a lot of fluid.  This makes it difficult to use the method for development or research.

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How can we measure the friction on wiper blades?

WHY

Wiper blades are of great importance to the safety of the driver. In reality they can operate under different speeds (various scales in the car) or under different lubrication conditions (from dry to wet with thin or thick film of water). To simulate these conditions in lab scale you need to have a versatile apparatus and you will need to use the actual components to be as close to reality as possible.  

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High speed sliding behavior of polymer coatings

WHY

Nowadays polymer based coatings are applied in all walks of life, due to their excellent corrosion resistance, low friction and cost, good surface finish, molding ability and low density. However, one of the main issue of these coatings is their relatively poor performance in terms of wear. Especially, when sliding under high speeds, frictional heating can lead to a softening of the coating and accelerate the wearing-off process. Evaluating the high speed sliding performance of polymer coatings is a key issue in many applications.     

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Compressor fluids under pressure: unexpected effects

WHY

Air conditioner compressor fluids have to prevent friction and wear under elevated gas pressure.  Standard Pin&Vee Block tests with gas 'bubbling' through the lubricant do not correlate with field behaviour, especially with CO2 as the cooling medium.  Another simulation with pressurized gas is needed.  We selected the Falex Block on Ring configuration, as it also recreates the line contacts and is able to work at higher speed than the Pin&Vee block machine.

HOW

Our Falex Block on Ring machine allows pressurizing the lubricant chamber with a gas, up to 10 bar.  Standard block-on-ring tests are done with and without pressure on the dissolved gas.  Tests with increasing contact loads (EP) and tests with constant load (Anti-wear) are done.

 b2ap3_small_BlockOnRing Applications | FACTLABS.ORG  b2ap3_small_BlockOnRingConfigs Applications | FACTLABS.ORG

 

RESULT

  • A sudden loss of lubricity in the CO2 pressurized oil bath can be measured.  Block temperature increases suddenly at 70°C, while lubricant temperature decreases, which indicates that CO2 bubbles are forming in the interface between block and ring. This phenomenon is only seen when the gas is dissolved under pressure in the lubricant.

b2ap3_thumbnail_Divergence Applications | FACTLABS.ORG

 

  • This leads to poor lubrication and increased wear.  Thanks to right additives, this bifurcation can be eliminated and wear prevention can be significantly improved under pressurized conditions.

b2ap3_thumbnail_Results Applications | FACTLABS.ORG

 

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Pre-screening the tribological properties of shock absorbers

WHY

Shock absorber component testing is expensive and time-consuming and this is a limiting factor in developing new materials for this application. There is a need to develop a pre-screening method to get a quick but accurate evaluation of the tribological behavior of materials, without losing too much correlation with the actual conditions (geometry, wear mechanism, load, speed, number of cycles etc.).

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Friction measurements on complex shapes

 

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Friction modifiers put to the test. Can we influence friction?

WHY

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. 

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Thermosetting polymers for high speed bearings: linking friction and heat

WHY

Polymeric materials are used more and more as cage material for light weight bearing applications, but thermoplastic materials suffer from PV limits.  At high speeds, the polymer may melt easily under light loads.  Thermoset resins don't have this limit, but may still disintegrate under higher temperatures.  In this method, we can apply high speeds and variable loads, to explore the limits of thermosets.

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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.

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Testing of oils for the automotive industry

WHY

A variety of oils for the automotive industry is available in the market. These oils have different composition, additives and can operate under different conditions (motion, load, speed and temperature). A method need to be used to prescreen the performance and endurance of these oils under different conditions, which are relevant to the automotive industry.    

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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

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.

b2ap3_thumbnail_10-station_ranking-polymers Applications

 

 

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High temperature sliding wear testing of materials

WHY

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.

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Composite polymers: How do they perform in water “tribocorrosion”

WHY

Polymer based composites are considered as one of the most important engineering materials for naval applications. They can be used in the superstructures, decks, bulkheads, advanced mast systems, propellers, propulsion shafts, rudders, pipes, pumps, valves, machinery and other equipment on large ships. In the majority of these applications these composites are subjected to mechanical loading in a corrosive environment. Thus their performance and/or lifetime is strongly dependent on both of these factors. In this application a methodology was developed to evaluate the effect of the corrosive environment (seawater) on the tribological performance of composite polymers is sliding contacts.  

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