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.
Skin creams are commonly used to improve skin health and create a smooth, soft, and moist perception. This is achieved by altering the surface roughness, friction, and adhesion of skin surface. Despite the fact that there are many commercial creams available, there is no consistent scientific approach to determine their frictional and adhesive properties.
In everyday life people use hairstyling products such as waxes or gels, to improve the holding of hair and improve/change its appearance. However, in the market there are many products available, claiming to have different characteristics (e.g. strong hold, silky/smooth touch…). To define the performance of such products, tribology comes into play. In particular two parameters are important. The friction determines how easy a wax or gel can be applied, whereas the stickiness and tackiness determine their holding ability.
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.
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.
In everyday life we come across and use applications were wires are operated in sliding contacts. Some examples are elevators, car doors, canopies etc. In the majority of these applications, friction is critical (e.g. the wire in a canopy should slide smoothly), and after a period of tuse, wear damage of the wire can also obstruct the performance.
One issue in the pharmaceutical industry, is the abrasion of processing components for pressing the powders. The intensity of the abrasion phenomena strongly depends on the composition and size of the processed powders. Up to date there is no fixed procedure on how to evaluate such abrasion phenomena, in conditions that simulate the realistic process.
Evaluating frictional and wear characteristics of very thin nanostructured layers with macro scale tribometers, in the Newton load range, can create unrealistic conditions. Wear phenomena are highly dependent on the contact conditions: such high loads are not relevant in the case of MEMS. The adhesive and capillary components that contribute to friction, in a micro-contact, can not be simulated with high load devices. Therefore, there is an increasing need to use new tribological testers and procedures to obtain a better understanding of surface interactions on an appropriate scale.
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.
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.
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.
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.