铸铁材料在边界润滑条件下形成薄片状磨屑的塑性流动机制AbstractIn this study, the formation mechanism of thin sheet-like debris in cast iron under boundary lubrication conditions was investigated based on the plastic flow mechanism. The results showed that the thin sheet-like debris was mainly formed by the shearing and breaking of the microcrystalline structure of cast iron under the action of tangential force during the sliding process. The formation of thin sheet-like debris was closely related to the content and distribution of graphite in cast iron. The study of the plastic flow mechanism of cast iron under boundary lubrication conditions can provide a theoretical basis for the design and selection of lubricants and materials to reduce friction and wear.IntroductionCast iron materials are widely used in various machinery and equipment due to their excellent mechanical properties and good casting performance. However, under the action of external loads, the frictional heat generated during the sliding process can cause severe wear of the cast iron surface, resulting in the formation of debris. The characteristics and formation mechanism of debris have a great impact on the performance and life of mechanical equipment. Therefore, it is of great theoretical and practical significance to study the formation mechanism of debris in cast iron materials under boundary lubrication conditions.TheoryUnder boundary lubrication conditions, the frictional heat generated during the sliding process cannot be effectively dissipated, resulting in high surface temperatures and high pressure conditions. As a result, the mechanical properties of cast iron materials are greatly reduced, and plastic deformation and fracture are prone to occur. Therefore, the study of the plastic flow mechanism of cast iron under boundary lubrication conditions is of great significance for revealing the formation mechanism of debris.MethodIn this study, the cast iron material was selected as the research object. The test was carried out on a pin-on-disk friction and wear tester under boundary lubrication conditions. The morphology and composition of the debris generated during the sliding process were observed and analyzed by means of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS).Results and DiscussionUnder boundary lubrication conditions, the graphite in cast iron will be exposed to the surface due to the peeling and spalling of the surface layer. During the sliding process, the tangential force acting on the surface of the cast iron material will cause the graphite to rotate and slide, and the microcrystalline structure of the cast iron will be sheared and broken, thereby forming thin sheet-like debris. The formation mechanism of thin sheet-like debris is closely related to the content and distribution of graphite in cast iron. When the graphite content is high and the distribution is uniform, the cast iron has good anti-wear properties and is less prone to debris formation. However, when the graphite content is low and the distribution is uneven, the cast iron is prone to plastic deformation and fracture, resulting in the formation of a large amount of debris.ConclusionThe study of the plastic flow mechanism of cast iron under boundary lubrication conditions can provide a theoretical basis for the design and selection of lubricants and materials to reduce friction and wear. The results of this study showed that the thin sheet-like debris in cast iron under boundary lubrication conditions was mainly formed by the shearing and breaking of the microcrystalline structure of cast iron under the action of tangential force during the sliding process. The formation of thin sheet-like debris was closely related to the content and distribution of graphite in cast iron.Moreover, it was found through the study that the size and shape of the thin sheet-like debris are influenced by the sliding speed and load, which affect the degree of plastic deformation and fracture of the cast iron material. With an increase in sliding speed and load, the amount and size of the debris also increase.The formation of thin sheet-like debris in cast iron under boundary lubrication conditions also has an impact on the wear of the material. The presence of debris on the surface of the material can lead to abrasive wear, which can further accelerate the wear of the material. Therefore, it is essential to understand the formation mechanism of debris and take measures to prevent the formation and accumulation of debris.One effective way to prevent the formation of debris in cast iron under boundary lubrication conditions is to use lubricants that have good boundary lubrication properties. These lubricants can reduce the tangential force acting on the surface of the material, thereby reducing the shearing and breaking of the microcrystalline structure and the formation of debris.In conclusion, the study of the p