ASTM G75-15 – Miller test

The Miller test allows for the evaluation of the abrasiveness of solid-liquid mixtures. The result of the Miller test is the Miller number, which indicates whether or not special precautions for wear protection are necessary. The Miller test is specified in the ASTM G75-15 standard.
In the field of wear testing, this is one of the few tests that are readily comparable internationally, as this standard has become widely accepted. The test can be conducted in two ways. It can be performed using either standard specimens or a standard mixture. Standard specimens are used to determine the abrasiveness of the mixture, while standard mixtures are used to determine the wear resistance of the specimen. The major advantage of this test method is its versatility with regard to the composition of solids and liquids. The ISAF generally uses a standard mixture.

For the Miller test, the wear specimens are clamped into the specimen holders and then immersed in a trough containing the solid-liquid mixture. The motor-driven rotor, via the eccentrically mounted drive rod, causes the specimens to oscillate (Figure 1). The volume of liquid in the troughs is sufficient to prevent the specimens from heating up due to friction.
Deviations from the standard test are possible upon consultation regarding the slurry and the sample material.