关键词: GH4169, 锯齿切屑, 有限元模拟, Johnson-Cook本构, 各项同性硬化本构, 绝热剪切

Abstract: The finite element modeling technologies of the high-speed cutting superalloy GH4169 were investigated to simulate the cutting process correctly, which include establishing the finite element model, selecting the material constitutive model, and determining the chip separation criteria and contacting friction model, etc. To simulate the chip separation process and research the chip formation mechanism in high-speed cutting GH4169, the two-dimensional orthogonal cutting finite element models were constructed using Johnson-Cook model and isotropic hardening material constitutive model respectively. As a result, two models obtained the similar serrated chip. On this basis, equivalent plastic strain, cutting temperature and cutting force curve were simulated further. To verify the validity of the finite element model, an experiment was carried out by high-speed turning GH4169 on the machine of CA6140, and the serrated chip generated from the turning experiment verifies the validity of two finite element models. The results show that the serrated chip sawtooth degree increases with the increase of cutting speed and the adiabatic shear is the main reason to cause the serrated chip on high-speed cutting superalloy GH4169. The cutting force curve and cutting temperature generated from the experiment accord better with model A, which demonstrates that model A exceeds model B in reflecting the machining characteristics of high-speed cutting GH4169.

Key words: GH4169, serrated chip, finite element simulation, Johnson-Cook constitutive, isotropic hardening material constitutive, adiabatic shear