Summary of the ASTM G99-17 Standard
This test method covers a laboratory procedure for determining the wear of materials during sliding, using a pin-on-disk apparatus. Specifically, materials are tested in pairs under nominally non-abrasive conditions.
For the pin-on-disk wear test, two specimens are required. First, a pin or ball is positioned perpendicular to the second specimen, usually a flat circular disk. In this setup, a stationary ball wears against a rotating disk at a controlled force and speed.
Throughout the test, parameters such as the coefficient of friction (COF), friction force, and wear are continuously measured. Afterward, the ball and disc wear volume is calculated from the ball wear radius and the disc wear width, respectively.
Wear Test Parameters
| Load: | 10 N |
| Speed and Velocity: | 0.1 m/s |
| Environment: | Room Temperature (~23 °C) Humidity (12-78%) |
| Test Duration: | 2.77 hours or 1,000 m of sliding distance |
| Data: | Friction Force (Fx) Normal Force (Fz) Rotary Velocity (T) Vertical Displacement (Z) Coefficient of Friction COF Acoustic Emission AE |
Data Summary
Throughout the test, the COF, down force, wear, and acoustic emission are recorded and reported in real time. Additionally, when two different materials are tested, it is recommended that each material be tested in both the pin and disk positions.
Finally, the data also includes a 3D image of the wear mark on the lower sample.
The table 1 shows data across various labs during inter-laboratory test on standard materials.
| Test # | Average COF at A | Average COF at B | Average COF at C |
| 1 | 0.66 | 0.65 | 0.59 |
| 2 | 0.61 | 0.64 | 0.51 |
| 3 | 0.63 | 0.65 | 0.60 |
| 4 | 0.66 | 0.61 | 0.62 |
| 5 | 0.61 | 0.65 | 0.61 |
| 6 | 0.63 | 0.64 | 0.60 |
| 7 | 0.62 | 0.60 | 0.64 |
| 8 | 0.61 | 0.62 | 0.52 |
| 9 | 0.63 | 0.65 | 0.59 |
| 10 | 0.64 | 0.66 | 0.64 |
| Average | 0.63 | 0.63 | 0.61 |
More on the Multi Function Tribometer Series Hardware
- Load sensor (N)
- Friction sensor (20 N)
- The typical pin specimen is cylindrical or spherical in shape. Typical cylindrical or spherical pin specimen diameters range from 2 to 10 mm.
- Universal ball holder
- 52100 steel ball – 6 mm
- Stainless Steel Disk (2 inch)
- Lower rotation drive
- Optional additional sensors
- Integrated 3D optical profilometer (for volume wear) on MFT-5000 and MFT-2000A platforms
- Temperature in option
- Humidity in option
- Acoustic emission in option
