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为了准确模拟高温合金GH4169高速切削过程,深入研究了高速切削GH4169的有限元建模技术,包括有限元模型的建立、材料本构模型、切屑分离准则以及接触摩擦模型等关键技术。为了模拟高速切削GH4169的切屑分离过程,研究切屑形态及其形成机理,分别采用Johnson-Cook和各项同性硬化本构关系模型对GH4169的高速加工过程进行二维正交切削有限元模拟,2种模型都获得了相类似的锯齿状切屑。在此基础上,模拟了基于上述2种模型的应力场、温度场和切削力曲线。为了验证有限元模型的有效性和正确性,在CA6140机床进行了GH4169高速车削实验,实验获得的锯齿形切屑验证了2种有限元模型的正确性,实验结果表明:随着切削速度的增大,锯齿状切屑的锯齿化程度增大;绝热剪切是导致高速切削GH4169生成锯齿状切屑的主要原因。实验测量的切削力曲线和切削温度场,与有限元模型A输出结果更好地吻合,进一步表明模型A比模型B更能反映GH4169的实际高速加工特性。
In order to accurately simulate the high-speed cutting process of superalloy GH4169, the finite element modeling technology of GH4169, including the establishment of finite element model, material constitutive model, chip separation criterion and contact friction model, is deeply studied. In order to simulate the chip separation process of high-speed cutting GH4169, the chip morphology and formation mechanism were studied. Two-dimensional orthogonal cutting finite element simulation of GH4169 high-speed machining process was carried out using Johnson-Cook and the isotropic hardening constitutive model. The models all obtained similar jagged chips. On this basis, the stress field, temperature field and cutting force curve based on the above two models are simulated. In order to verify the effectiveness and correctness of the finite element model, the GH4169 high-speed turning test was carried out on the CA6140 machine tool. The jagged chip obtained in the experiment verified the correctness of the two finite element models. The experimental results show that with the increase of cutting speed , Jagged chip sawing degree increases; adiabatic shear is the main reason leading to high-speed cutting saw blade serrated chip GH4169. The experimentally measured cutting force curve and cutting temperature field are in good agreement with the output of finite element model A, which further shows that model A can reflect the actual high-speed machining characteristics of GH4169 better than model B.