Tuning microstructures of TC4 ELI to improve explosion resistance

Abstract

A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion resistance. However, there is limited investigation on tuning microstructures of TC4 ELI to improve explosion resistance. Moreover, the current challenge is quantifying microstructural changes’ effects on explosion resistance and incorporating microstructural changes into finite element models. This work aims to tune microstructures to improve explosion resistance and elucidate their anti-explosion mechanism, and find a suitable method to incorporate microstructural changes into finite element models. In this work, we systematically study the deformation and failure characteristics of TC4 ELI plates with varying microstructures using an air explosion test and LS-DYNA finite element modeling. The Johnson‒Cook (JC) constitutive parameters are used to quantify the effects of microstructural changes on explosion resistance and incorporate microstructural changes into finite element models. Because of the heat treatment, one plate has equiaxed microstructure and the other has bimodal microstructure. The convex of the plate after the explosion has a quadratic relationship with the charge mass, and the simulation results demonstrate high reliability, with the error less than 17.5%. Therefore, it is feasible to obtain corresponding JC constitutive parameters based on the differences in microstructures and mechanical properties and characterize the effects of microstructural changes on explosion resistance. The bimodal target exhibits excellent deformation resistance. The response of bimodal microstructure to the shock wave may be more intense under explosive loading. The well-coordinated structure of the bimodal target enhances its resistance to deformation.