Four Ball Tester

The tester can perform both Wear Preventative (WP) and Extreme Pressure (EP) analysis. Three balls are brought together in a clamped fashion. The fourth ball sits on top of the three balls and rotates for a fixed period of time. The load on the 4th ball can be varied.

In Wear Preventive (WP) tests the average scar diameter on the bottom three balls is reported. The size of the scar shows the ability of the lubricant to prevent wear. Loads applied during wear tests, produces circular wear scar on each ball and the average wear scar diameter is determined for comparison. Wear scar diameter on the steel balls are measured using an image acquisition system.

In Extreme Pressure (EP) tests the lubricant is subjected to load that is increased in specified steps after every run. The load is increased continuously till a load is reached where the lubricant fails. Welding of the bottom three balls to the top ball indicates failure of lubricant. The load at which welding occurs represents extreme pressure property of the lubricant.

The normal load, friction force, and temperature can be monitored using Windows-based Data Acquisition Software.

See YouTube video.

Reciprocating Sliding Friction and Wear test

The Reciprocating Sliding Friction and Wear test can be used to measure average coefficient of friction (COF) and wear. It is possible to perform dry and lubricated tests. Different types of contact geometries are possible such as Ball-on-disc, ball-on-plate, cylinder-on-disc, cylinder-on-plate and disc-on-disc. Load, Frequency, Stroke length and Temperature can be varied according to requirements.

See YouTube video.

Dry sand rubber/wheel abrasion test

Dry sand rubber/wheel abrasion test is one of the most widely used abrasion testing method. Low-stress scratching abrasion is simulated in the test by trapping a stream of free-falling abrasives between a wear specimen and a rotating rubber coated wheel. The wear is usually determined by weight loss. A wide range of materials can be tested for example; metals, ceramics, plastics, composite materials and coatings.

See YouTube video.

Falex Pin & Vee Block Test

The Falex Pin & Vee Block Test Machine is a laboratory tool for evaluating wear, friction and extreme pressure properties of materials and lubricants. A steel journal is locked in place with a brass pin. Two V-blocks surround the journal while it rotates. The blocks apply increased pressure over time. The wear on the blocks can be measured to determine how much of the block was worn away.

See YouTube video.

Timken Test

In this apparatus a ring (‘test cup’) rotating at 800 [rpm] is pressed against a stationary slab (‘test block’) in the presence of the lubricant tested. The test is conducted for ten minutes at successively higher loads until ‘OK’ and failure loads are determined. The ‘OK’ is the highest standard load at which the spinning bearing race produces no scouring mark on the test block, but only a uniform wear scar.

See YouTube video.

High temperature Tribometer

High temperature Tribometer are used for analysis of friction and wear properties of materials at elevated temperatures. These tribometers can be used to measure friction and wear at temperatures as high as 1200-1500oC. These kind of tribometers generally use a furnace or insulated chamber equipped with heating coils to obtain high temperatures.

See YouTube video.

Low temperature Tribometer

Low temperature Tribometer are used for analysis of friction and wear properties of materials at very low temperatures 0 to -50oC. These are generally used for testing materials used in space applications or for very low temperature regions (pipelines in polar regions eg. Siberia). These kind of tribometers generally use liquid nitrogen or liquid helium to cool the interface.

Vacuum Tribometer

Vacuum Tribometer are designed to provide controlled vacuum conditions (10E-7 mbar) for friction and wear studies. Some of the tribometers are equipped with heating devices to perform tests at high temperature.

See YouTube video.

Micro Tribometer

Used for Micro-tribology. Micro Tribometer allows the use of small forces on test samples. It tribological analysis of soft materials, such as contact lenses, cartilage, skin etc.

Nano Tribometer

Used to investigate tribological properties of a wide range of surfaces and interactions at atomic level.

See YouTube video.

Scratch Test Instrument

Scratch test instrument is a simple for evaluating adherence characterization and scratch resistance for thin coatings and bulk materials. A stylus with well-defined tip geometry is moved over a specimen surface with load until failure occurs at critical load or loads.

See YouTube video.

Taber Abraser Test

Taber Abraser test is used for measuring the abrasive wear resistance of a material. Test specimens are cut in shape of a disc. Then the specimens are placed on the turn-table and are subjected to rubbing action of a pair of rotating abrasive wheels at known weights.

See YouTube video.

Air Jet Erosion Test

Used to test materials, coatings, surface treated parts under erosive environment/conditions. The test sample is subjected to a high speed stream of abrasive particulate gas for a certain duration and after test completion, the sample is checked for wear. The result of the test is reported as the loss of weight of the sample.

See YouTube video.

Water/Slurry Jet Erosion Test

Similar to air jet erosion test.

See YouTube video.

Tribocorrosion test systems

Used to test tribocorosion. Reciprocating tribometers are modified and are incorporated with electrochemical test set-up to study of the simultaneous action of sliding and corrosion.

References:

  1. Bhushan, Bharat. “Chapter 12: Friction and Wear Screening Test Methods.” Springer Handbook of Nanotechnology. Berlin: Springer, 2006 Google books preview only
  2. Stachowiak, Gwidon W., Andrew W. Batchelor, and Grazyna B. Stachowiak. “Chapter 3: Tribometers.” Experimental Methods in Tribology. Amsterdam: Elsevier, 2004 Google books preview only
  3. Koehler Instrument Company, http://www.koehlerinstrument.com/tribology-index.html
  4. Ducom Instruments, Test Instruments http://ducom.com/
  5. Falex tribology, http://www.falexint.com/en/materials http://www.falexint.com/en/lubricants
  6. Anton Paar GmBH, http://www.anton-paar.com/corp-en/products/group/tribometer/
  7. ST Instruments http://www.stinstruments.com/mechanical-testing/
  8. Bruker https://www.bruker.com/products/surface-and-dimensional-analysis/tribometers-and-mechanical-testers.html
  9. com http://ayalytical.com/wp-content/uploads/2015/12/NE-4Ball-2.pdf
  10. Four Ball Test by Faiz Islam https://www.scribd.com/doc/77921431/Four-Ball-Test