The Impact of Stones on the Wear of Agricultural Tools

Sammanfattning

The agricultural industry is one of the largest and most important ones in human society. An important part of this system is related to the soil preparation, and one issue that the industry faces is the wear rate of the tools used for the preparation of the soil. The aim of this project was to broaden the knowledge about how the materials used in agricultural tools are worn by collisions with stones, since stones are one of the components found in agricultural land. Experiments were performed using a tribological test rig which was improved by some alterations as part of the project. The parameters that were varied during the experiments were the collision speeds between the stones and samples, the mass of the stones and their shapes. The results showed that the surface damage on the samples increases with increased collision speed and stone size. The results also showed that the appearance of the surface damage varies with the stone shape. The topography of the surface damage was also shown to vary depending on the stone size and shape. In addition to the stand-alone stones used in the experiments, pilot experiments using stand-alone aggregates as well as a stone planted in soil were also performed and shown to result in different amounts and types of surface damage than the stand-alone stones did. Collision tests with the aggregates resulted in more of a scratched appearance for the surface damage on the sample surface. The tests with a stone planted in soil resulted in a constellation of different surface damages scattered across larger areas of the sample surface. The surface damages were both more in number and larger in size compared to the surface damage caused by stand-alone stones.