碳化钛颗粒增强钢基复合材料超声振动辅助划痕仿真及试验研究

Titanium carbide (TiC) particle-reinforced steel matrix composites have high strength, hardness and wear resistance and are widely used in precision aerospace parts. Due to the presence of TiC hard particles of the material, resulting in poor machined surface quality and severe tool wear, Ultrasonic vibration-assisted machining has been attempted to solve this problem, but the removal mechanism for this material under ultrasonic vibration-assisted machining conditions is unclear. By conducting ultrasonic vibration-assisted scratch simulation and experimental studies, the removal mechanism of this material under ultrasonic vibration-assisted conditions is investigated. A finite element simulation model of the material is first developed based on the size, morphology and distribution characteristics of the TiC particles and the material properties of the particles and the substrate, and then the material removal characteristics and surface creation mechanism during ultrasonic vibration-assisted scratching of a single diamond are analysed and validation tests were carried out. The results show that: the predicted scratch force of the simulation model is less than 16% of the experimental value; during the scratching process, the maximum stress on the TiC particles is tensile and the maximum stress on the matrix is compressive; compared with conventional scratching, the single diamond is intermittently separated from the workpiece during the ultrasonic vibration-assisted scratching process, and the scratch force shows a cyclical change, with an average scratch force reduction of 16%-50%. Under ultrasonic vibration-assisted conditions, the plastic deformation of the substrate material is greater due to the hammering effect of the single diamond on the TiC particles, and more particles are debonded from the substrate into chips, resulting in a larger cavity on the scratch surface, which can provide guidance for the selection of process parameters in the subsequent machining process.