Tham khảo tài liệu 'abrasive materials_2', kỹ thuật - công nghệ, điện - điện tử phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Abrasive Particle Shape Parameters 17 Abrasive Particle Shape Parameters Basic Shape Definitions The following three basic shape definitions are provided for abrasive particles used for blast cleaning applications shot grit cylindrical. The corresponding designations are listed in Table . Examples for two shape definition are displayed in Fig. . The term shot characterises grains with a predominantly spherical shape. Their length-to-diameter ratio is 2 and they do not exhibit sharp edges or broken sections. The term grit characterises grains with a predominantly angular shape. These grains exhibit sharp edges and broken sections. The term cylindrical denotes grains that are manufactured by a cutting process. Their length-to-diameter ratio is 1. This shape can only be found with cut steel wire pellets. Relative Proportions of Particles Shape parameters characterise the shape of individual particles. Wadell 1933 and Heywood 1933 were probably the first who gave rigorous analyses of shape parameters. Heywood 1933 considered the shape of a particle to have the following two distinct characteristics the relative proportions of length breadth and thickness the geometrical form. The relative proportion includes two parameters 1 the elongation ratio rE and 2 the flatness ratio rF . Both parameters are defined and illustrated in Table . Bahadur and Badruddin 1990 applied the elongation ratio to investigate the influence of the abrasive particle shape on particle impact erosion processes. They found notable relationships between abrasive type abrasive particle diameter and abrasive particle shape. Some results of their study are provided in Fig. . Silica carbide particles became more elongated and less circular with an increase in the particle size while the opposite was the case with aluminium oxide particles. The general variation of silica oxide was similar to that of silica carbide particles though not as systematic. The elongation ratios
