Multiscale modeling of cutting processes for TiBw/TA15 composites based on the interface model parameters identification method by microcolumn compression

Abstract

TiBw/TA15 composites are featured by the network-structured distribution of the reinforced phase quasi-continuously. The multiphase microstructure including the TiB ceramic whisker reinforcement, the titanium alloy matrix and the interface plays a significant role in cutting processes. In this paper, multiscale finite element (FE) cutting models in accordance with the structural characteristics of TiBw/TA15 composites are established. Then, the interfacial mechanical parameters of TiBw/TA15 composites are recognized by the microcolumn compression approach, and the thermoplastic equivalent constitutive parameters (ECP) of the TiBw-rich region in the model are obtained by a two-step FE simulation. The cutting model is validated by orthogonal turning experiments. Finally, the formation of segmented chips can be visualized by the cutting models, which is caused by the compressive stress and the TiB whiskers failure. In addition, the mapping relationship between the critical equivalent strain (CES) and the hardened layer depth (HLD) is established. The results indicate that the HLD reduces with the decrease of cutting speed (VC) and depth of cutting (h). The findings in this paper facilitate a further understanding of the TiBw/TA15 composites cutting mechanism.