This article establishes a finite element method (FEM) model to characterize and classify the chip morphologies of Inconel 718, which tends to form shear localized chips. Orthogonal cutting simulations in a wide range of speeds with three uncut chip thicknesses are carried out to model the plastic deformation of Inconel 718 and thus the formation of the serrated chips by utilizing the Johnson-Cook (JC) constitutive law with the criterion of the accumulated plastic strain. Evolution trends of the chip deformation results are of the main interest and focus is placed on the chip segmentation. Simulation results show that Inconel 718 exhibits a chip pattern transition from the continuously smooth form to the regularly serrated form with the increase of cutting speed. However, the disappearance of chip serration is also observed at still higher cutting speeds. The primary shear angle and the segment inclination finally reach the same asymptotic value of 45^∘. The shear band spacing drops significantly before the two plateau regions are achieved. Apart from these, the scatter plot of specific cutting force tends to be a concave shape, while the scatter plot of chip segmentation degree tends to be a convex shape. Meanwhile, the chip thickness ratio approaches an asymptotic value, and the average velocity of chip sliding on the tool rake face almost equals the cutting speed. At the same time, the simulation results are compared to the results by experiments or simulations in the published literatures. Moreover, the FEM model is validated by comparing the chip morphologies from the experiments and the simulations, respectively. The proposed work is fundamental for not only increasing understandings of the metal cutting process of Inconel 718, but also hypothetically providing a framework of the chip generation under the cutting speed from low to high range.

本文建立了一个有限元方法（FEM）模型来表征和分类 Inconel 718 的切屑形态，它倾向于形成剪切局部切屑。以三种未切削切屑厚度在很宽的速度范围内进行正交切削模拟，以模拟 Inconel 718 的塑性变形以及锯齿状切屑的形成，利用 Johnson-Cook (JC) 本构定律和累积的标准塑性应变。切屑变形结果的演变趋势是主要关注点，重点放在切屑分割上。仿真结果表明，随着切削速度的增加，Inconel 718 呈现出从连续平滑形状到规则锯齿形状的切屑图案过渡。然而，在更高的切削速度下也观察到切屑锯齿的消失。主剪切角和段倾角最终达到相同的渐近值 45^∘. 在达到两个平台区域之前，剪切带间距显着下降。除此之外，特定切削力的散点图往往呈凹形，而切屑分割度的散点图则呈凸形。同时，切屑厚度比接近一个渐近值，切屑在刀具前刀面上滑动的平均速度几乎等于切削速度。同时，将模拟结果与已发表文献中的实验或模拟结果进行比较。此外，通过分别比较来自实验和模拟的芯片形态来验证 FEM 模型。所提议的工作不仅是增进对 Inconel 718 金属切削工艺的理解的基础，