WEAR PATTERNS OF SOIL CUTTING BLADES

Abstract

The paper presents the results of laboratory tests of the wear of soil tillage blades. The authors have developed an experimental unit with a linear-moving sample blade when interacting with an abrasive medium imitating the real soil. Physical properties of the abrasive medium can be changed by incorporating into the composition quartz particles, paraffin, ceresin, pulverized cement and other materials. The installation reproduces the operation of a blade shearing off soil particles of a loamy soil. The authors have obtained relationships between the inclination angle, the blade wear land width and length and the cutting path. As the depth of cutting increases, the wear rate increases in a parabolic manner. Due to the wavy irregularities of the furrow bottom, the wear rate decreases by 10...15%. It is caused by a load decrease of treated abrasive medium regardless of the blade material (steel or aluminum alloy). With the hardness of medium increases to more than 2 MPa, the blade wear rate increases, but the wear land angle to the furrow bottom decreases due to a changed wear mechanism. As fine dust particles concentration in abrasive medium increases, a facet formed on the blade edge contributes to its rapid blunting. As the cutting speed increases from 0.3 to 0.6 m/s, the blade wear rate increases by 25.. .30% due to raising soil resistance and the specific energy spent on soil deformation and destruction.