Sliding and rolling equipment

Locations: Building 7 room 2023

The nCATS facility is equipped with a range of instruments for conducting wear testing and measuring friction under both dry and lubricated conditions. These include:

  • Plint TE77 reciprocating tribometer
  • Plint TE74S twin disc tribometer
  • Pin-on-disc 1
  • Pin-on-disc 2
  • Plint TE66 microabrasion
     

Plint TE77 reciprocating tribometer

The TE 77 High Frequency Friction Machine, manufactured by Phoenix Tribology Ltd., is a PC‑controlled tribological test system designed for precise control and measurement of friction and wear parameters. It is supplied with a floor‑standing bench and an integrated control unit incorporating a SUPERSLIM Serial Link Interface Module, connected to a host PC running COMPEND 2000 software for sequence control and data acquisition. The system enables programmable control of load, frequency and temperature, alongside low‑ and high‑speed data logging.

Test specimens are mounted in a moving carrier that accommodates a range of contact geometries through interchangeable clamping fixtures, including point, line and area contacts. Motion is provided by a motor‑driven cam and scotch yoke mechanism, generating pure sinusoidal oscillation against a fixed lower specimen mounted either dry or in a lubricant bath. Stroke length is manually adjustable via eccentric cams, allowing a wide range of oscillation amplitudes.

Normal load is applied through a lever mechanism actuated by a geared servomotor and measured using a strain‑gauge transducer positioned directly beneath the contact. Friction force is measured by a piezoelectric transducer with signal conditioning to ensure accurate frequency response. Electrical isolation of the specimens allows contact potential measurement, enabling assessment of metallic contact, film formation and surface degradation during testing. Data are stored in standard spreadsheet‑compatible formats.

Tribometer specifications:

  • load range: 5 to 1000 Newtons (N)
  • force range: –500 to 500 N
  • loading rate: 50 Newton-second (N/s)
  • temperature range: ambient to 600°C
  • heating power: 800 Watts (W)
  • frequency range (there is a 20:1 reduction gearbox that allows frequencies down to 0.1 Hz): 2 to 50 Hertz (Hz)
  • stroke range: 0.4 to 25 millimetre (mm)
  • linearity: 0.50 per cent (%)
  • maximum velocity: 1 m/s (20 Hz at 25 mm stroke)
     

Sensors:

  • temperature: k-type thermocouple
  • contact potential: 50 millivolt (mV) direct current (DC) signal
  • friction transducer: piezo-electric type
  • stroke transducer: magneto inductive
     
TE77 reciprocating tribometer
TE77 reciprocating tribometer

Plint TE74S twin disc tribometer

The TE 74 Two Roller Machine, manufactured by Phoenix Tribology Ltd., is a tribological testing system designed to investigate traction, wear and rolling contact fatigue under heavily loaded and lubricated conditions. It operates in both pure rolling and combined rolling–sliding regimes and employs two motors, one to supply input power and the other to absorb transmitted power, allowing controlled traction measurements.

High contact pressures are achieved through the application of large loads to small‑diameter rollers mounted in a fully supported configuration, with bearings located on either side of each roller. Consequently, the spindle bearings operate within the test lubricant. Normal loading is applied using a servo‑controlled pneumatic bellows actuator with force transducer feedback. The lower roller drive incorporates an in‑line torque transducer, while a vibration sensor enables detection of surface failure. Electrical insulation of the upper roller housing and slip rings on the shafts permit electrical contact resistance measurements. A standard lubricant service module provides heating, circulation and cooling. 

PC‑based programmable control and data acquisition are implemented using COMPEND 2000 software, with data stored in spreadsheet‑compatible formats.

Tribometer specifications:

Type:  

  • circulating power
  • fully supported roller
  • spindles adjacent
  • fixed shaft centre distance

 

  • contact: line or point contact
  • test conditions: pure rolling; sliding/rolling
  • environment: lubricated
  • standard roller diameters: 40 mm on 40 mm
  • maximum roller difference: 65 mm on 15 mm
  • maximum roller thickness: 12 mm
  • maximum load: 12 kilonewton (kN)
  • roller temperature: ambient to 150°C
  • motor power: 5.5 kilowatts (kW)
  • motor base speed: 1500 Revolutions Per Minute (rpm)
  • motor maximum speed: 3000 rpm


Drive ratio 1:1

  • maximum roller speed: 3000 rpm
  • maximum torque at 3000 rpm: 17.5 N
  • maximum surface speed (40 mm roller): 6.28 m/s

Drive ratio 2:1

  • maximum roller speed: 6000 rpm
  • maximum torque at 6000 rpm: 8.75 Newton-meters (Nm)
  • maximum surface speed (40 mm roller): 12.56 metre per second (m/s)
     
Plint TE74S twin disc tribometer
Plint TE74S twin disc tribometer

Pin-on-disc (PoD) tribometers

PoD1 is a smaller faster version, which was used for early developments of electrostatic charge measurements in steel-steel and hybrid contacts, later projects explored carbon brakes with the latest work studying polymer brushes. 

PoD2 is a low speed machine developed from an abrasive wheel machine that operates a low-speeds but high torques; over the year this has been used in various research and consultancy projects from wire-line wear to stone/rock on steel lubricated with water-base muds to simulate downhole conditions.  Electrochemical measurements and polarisation have been used to explore corrosion and to affect friction.  The latest projects are looking at wheel squeal and brake dust generation.

Pin-on-disc specifications: 

Pin-on-Disc 1 

  • load range: 5 to 260 N
  • velocity range: 100 to 3000 rpm
  • linear velocity range: 0.2 to 14 m/s
  • temperature range: ambient  


Pin-on-Disc 2

  • load range: 40 to 500 N
  • velocity range: 10 to 240 rpm
  • linear velocity range: 0.02 to 2 m/s
  • temperature range: ambient
Pin-on-disc (PoD) tribometers
Pin-on-disc (PoD) tribometers

Plint TE66 microabrasion

The TE 66 Micro‑Scale Abrasion Tester, manufactured by Phoenix Tribology Ltd., is a laboratory instrument designed for the measurement of coating thickness and the evaluation of wear behaviour at the micro‑scale. The system operates by rotating a fixed ball against a coated flat specimen in the presence of an abrasive slurry, producing a circular wear scar. Progressive wear leads to the formation of a characteristic “bulls‑eye” pattern as the coating is penetrated and the substrate becomes visible. Measurement of the inner and outer diameters of this wear scar provides a well‑established, accurate and cost‑effective method for determining coating thickness.

For wear coefficient determination, precise control and measurement of ball rotational speed, applied load and total number of rotations are required in order to calculate sliding distance and wear rates over extended test durations. In the TE 66 configuration, a 25 mm diameter ball is clamped between two coaxial shafts supported by bearings, with one shaft driven by a variable‑speed DC geared motor. A batch counter records shaft revolutions. The test specimen is mounted on a vertically suspended, counterbalanced beam, with load applied via dead weights. Abrasive slurry is delivered to the contact using a peristaltic pump from an agitated reservoir. 

The apparatus conforms to BS EN 1071‑6:2007.

Rig specifications:

  • ball speed range: 30 to 150 rpm
  • load range: 0.05 to 5 N
  • ball diameter: 25 mm
  • pump feed rate: up to 60 milliliters per hour (ml/hr)

 

Plint TE66 microabrasion
Plint TE66 microabrasion