Research on the vibration cutting performance of particle reinforced metallic matrix composites SiCp/Al

摘要

The cutting performance of particle reinforced metallic matrix composites (PRMMCs) SiCp/Al in ultrasonic vibration cutting and common cutting (CC) with carbide tools and PCD tools was researched experimentally in this work. The changing rules of chip shape, deformation coefficient, shear angle surface residual stress and microstructure in ultrasonic vibration cutting are presented. The result shows that when adopting CC, a spiral chip with a smaller curl radius will be obtained. The chip of zig-zag contour, is short and thick. There are numerous sheet cracks both on the face of the chip and on the machined surface. That is to say, the cutting process of metallic matrix composites (MMCs) is not like the cutting process of plastic material, but is similar to the breaking process of brittle material. By comparison, when adopting ultrasonic cutting, the deformation of chip is small, and a loose spiral chip with a larger curl radius that is long and thin is produced. The phenomenon is similar to the vibration cutting of plastic material, but the chip still belongs to the group of plastic or semi-plastic segmental chips due to the structure characteristics of the material itself. Furthermore, the tangential residual compression stress of vibration cutting is larger than that of CC, the axial residual stress has a relationship to the feed rate, and the residual stress does not change obviously with cutting depth and they are of the same order of magnitude on the whole. According to the microstructure, ultrasonic cutting can reduce the influence of tearing, plastic deformation and built-up edge in cutting and can restrain flutter so as to make the cutting process more stable.