Assessing the role of particle shape and scale in abrasion using ‘sharpness analysis’: Part II. Technique evaluation

In this paper, the sharpness analysis technique—as developed and described in Part I—is applied to real particles for the express purpose of understanding the role of particle shape and size in abrasion. The shape of particles is measured by shape properties; and these are compared to determine whether the notorious particle size effect is indeed caused by changes of particle shape with scale. The experiments conducted thus far suggest that this is not the case, and that the particle size effect is more likely to be caused by other phenomena; i.e. abrasive clogging, scale-dependent material strengthening, and changes to the spatial distribution of particles and their asperities as a result of the manufacturing process. The particles tested demonstrated no distinct relationship between shape and size. In fact, within the confines of sampling error, it is possible to suggest that the particles exhibited geometrical similarity at different scales. This interesting result explains why wear-rate is independent of particle size above the critical size, but also eliminates particle shape as a direct cause of the particle size effect.