Papers by Author: Hong Du

Abstract: The workpieces of fine blanking with negative clearance were obtained through the fine-blanking with negative clearance processing experiment. The fractography photographs of workpieces shearing surface were scanned by scanning electron microscope (SEM), and the characterization parameters and quality standard of workpieces shearing surface with negative clearance were analyzed in the processing of blanking. According to the characterization parameters and quality standard of workpieces shearing surface with negative clearance, the workpiece with the length ratio of burnish band, deflection error, rollover error and blanking burr were analyzed qualitative. The findings have a certain reference value to the blanking related profession.

Abstract: The different separation mechanism of fine-blanking with negative clearance and conventional blanking under different blanking process are analyzed through fine-blanking with negative clearance and conventional blanking processing experiments on AISI-1045 steel. The fractography photographs in the different deformation regions, such as rollover zone, shearing band, fracture zone and burr zone are scanned by scanning electron microscope (SEM-JSM-6360LV). The place of fracture of fine-blanking with negative clearance has emerged into the middle of work piece not the undermost of workpiece, and the width of fracture band is as tiny as 50-100 micron. The smooth surface formed by the uniform plastic flow in the process fine-blanking with negative clearance, and the full course of finally toughness fracture have been analyzed in the final phase of ejecting in fine-blanking with negative clearance. From the perspective of material meso-damage, the fracture mechanism of special blanking process with negative clearance has been illustrated in details.