The BICERI universal wear machine is thought to be the only laboratory rig available that is capable of testing all three common test geometries. This is achieved by fitting different modules in place of the standard pin-on-disc unit. These modules and other optional systems allow the rig to test surface fatigue, abrasive wear and adhesive wear under realistic operating conditions, including dry, lubricated and three-body and at elevated temperatures. The testing of lubricants such as greases and oils can be accomplished using standard contacting material pairs. A corrosion resistant feed system is available for testing in salt water and acids.
The rig consists of a rigid cabinet housing the inverter-controlled variable-speed 2.2kW four-pole electric motor drive, and is fitted with a substantial steel top plate on which the modules are bolted. Motion is transmitted to each module via a toothed belt drive with interchangeable pulleys. By varying the speed, load and sample temperature a wide range of operating conditions can be produced.
The three test modes are:
- Pin-on-reciprocating plate (simulating the piston/cylinder bore interface), the plate being supported on a pair of ball bushings. ASTM F372 is the appropriate US standard test
- Pin-on-disc (for vane pump and transmission component simulation) and ASTM G99 tests
- Block-on-ring (for cam and follower and gear tooth contact simulation) and the ASTM G77 test
The maximum load of 2kN in the pin-on-disc test, applied by dead weights on a lever, is higher than for most competing test machines, allowing testing under realistic loads, rather than having to extrapolate from lower loads. A force post-assembly with a linear voltage displacement transducer (LVDT) measures friction. Another LVDT measures vertical movement of the load arm resulting from wear. Test data are stored in Windows-based computer software.
Using multipurpose, adjustable pin holders it is possible to hold wear specimen of different sizes and shapes, and to set the pin at any angle. Typical pin compositions include diamond point, tungsten ball, a test material, or a surface-treated or coated material. The pin-on-disc module can be set for single or multiple traverses, for lubricated or dry testing and for two or three-body abrasive wear tests. The disc is located within a stainless steel container that collects wear debris during dry testing and holds lubricants during lubricated testing.
A variety of test parameters can be altered to suit a multitude of applications:
- Shape of contact: nominally point, line, area
- Disc diameter: 30-150mm
- Speed range: 20-500rpm
- Maximum fluid temperature: 250°C
- Lubrication Conditions: Lubricated/Dry
- Method of Lubrication: Immersed, thin layer, drip fed
- Friction Force: Can be displayed on an oscilloscope but is normally logged to file to show friction evolution
- Wear: Not directly measured but normally used in conjunction with the profilometer and microscope for wear scar evaluation