Microstructure-based 3D Finite Element Model for Micro Drilling Carbon Steels

It is well recognized that microstructure controls the physical properties and thermo-mechanical behaviour of a material. The complexity of the microstructure often makes it very difficult to simulate the material behavior in cutting processes using analytical or numerical modeling techniques. This paper presents a three-dimensional finite element approach to incorporate microstructure into micro cutting simulation based on the concept of a representative volume element (RVE) and constitutive material modeling. For this purpose, the Lagrangian formulation proposed in the implicit FE code Deform 3DTM was applied. Micro drilling tests with solid carbide twist drills in different diameters (d = 100 μm - 1 mm) were performed on ferritic-pearlitic carbon steels C05, C45 and C75 for the verification of the developed 3D multiphase FE computation model. The microstructure-based 3D FE model was successfully validated regarding chip formation, feed force, and torque. A realistic prediction of size effects identified in micro drilling tests could also be obtained.