Grain size influence on chip formation in high-speed machining of pure iron

• DOI: 10.1007/s00170-020-05512-6
• Publication Date: 2020-05-26T22:02:38Z
• Authors: Xiuxuan Yang; Bi Zhang; Qian Bai; Meng Zheng; Jingang Tang
• Keywords: 0203 mechanical engineering; 02 engineering and technology

Same metallic materials with varied grain sizes have different material behaviors and are used in different industrial applications. However, machining parameters are normally determined by the materials, and the grain size effect has not been investigated in detail in a machining process. This paper studies the influence of grain sizes for pure iron on cutting force and chip formation in the high-speed machining with a speed of 24 m/s. A grain size–dependent material constitutive model is proposed and calibrated by the split Hopkinson pressure bar tests and then implemented into a finite element model of the high-speed machining process. The cutting force and chip morphology from simulation results have a good agreement with those from cutting experiments. The results show that a smaller grain size leads to more serrated chips in high-speed machining of pure iron due to the thermal- and mechanical-coupled effect at the shear band zone. Under the high-strain and high-temperature conditions, grain refinement occurs in the serrated chips.