Multiscale modeling of Ti/TiB composites

Titanium and its alloys have broad applications in the industry due to their high specific strength and chemical resistance. However, they suffer from low elastic modulus, wear resistance, and strength at elevated temperatures. Titanium boride whiskers (TiBw) are one type of reinforcement that have shown promising results in improving the wear behavior, hardness, high-temperature strength, and elastic modulus of titanium. Such composites are good candidates for applications in the automotive, aerospace, and biomedical industries. TiB is not a naturally occurring compound, and many of its properties can only be obtained indirectly. Due to the inaccessibility of TiB whiskers and the infeasibility of conducting costly experiments to obtain their properties indirectly, computational techniques could be used as an alternative method to derive the required properties.

This research aims to use computational materials science and computational mechanics techniques in multiscale modeling of Ti/TiB composites. At the molecular scale, we use density functional theory (DFT) to investigate the interface between Ti/TiB. For investigations at finite temperatures, firstly, we develop interatomic potentials for B-B and Ti-B bonds based on a series of properties obtained from DFT. Then, the developed potentials are used in molecular dynamics (MD) simulations to study the temperature dependence of the material properties of TiB and cohesive zone parameters for Ti/TiB interfaces at the nanoscale. At last, we incorporate the cohesive zone model parameters in macroscale simulations and perform finite element analysis (FEA) to assess the failure modes of Ti/TiB composites.