Abstract
Grinding tests on brittle materials were carried out both under reduced pressure and under atmospheric pressure, using a laboratory hammer mill and a vacuum vessel. Finer products were obtained under reduced pressure than under atmospheric pressure.
To explain the experimental results from the standpoint of single fracture, a model calculation was carried out by using a simplified model of the hammer mill. In the model calculation, the friction drag of air, the effect of atmospheric pressure on the strength of brittle particles, the dependence of Young''s modulus, Poisson''s ratio and the strength on the loading rate, and the dependence of the strength on the particle''s volume were taken into account. It was found that a part of the experimental results was explained by the model calculation.
