Forms And Types of Abrasive Wear

Abrasive wear is typically categorized by the contact environment and the type of contact. The contact type defines the abrasive wear mode.Abrasive wear occurs when a hard surface or hard particles pass over a soft surface, causing loss of material . Abrasive wear can be divided into two groups: two-body and three-body abrasive wear . In the three-body abrasion, the particles formed during the operation or coming from outside the system cause the abrasive wear, whereas in two body, one of the materials plays the role of the abrasive. Two-body abrasive wear - This type takes place when hard particles or grit eliminate material from the opposing surface. This can be best described by thinking of a material being displaced or removed through a plowing or cutting operation. Three-body wear - This occurs when the particles are unconstrained and are able to slide down and roll on a surface. The environment of contact defines whether the classification of wear is a closed or open type. An open wear environment takes place when surfaces are adequately displaced to become free of each other. Abrasive wear has three different forms: microcuting, wedge forming and ploughing . During operation of a system, transition from one mode to another may happen and modes can act simultaneously. In the ploughing mode, a shallow groove is formed and repeated loading is necessary to form a wear particle. In the wedge forming, the wedge type of wear debris is formed. In the microcutting mode, long, curled ribbon-like particles are generated. The shape of the abrasive particle, the hardness, the load and the shear strength at the contact interface determine the state of the abrasive wear. The abrasive wear coefficients of metals are in the range of depending on the conditions, which is larger compared to adhesive wear. Thus, abrasive mode is mainly a severe type of wear.