Investigation of densification behavior of tungsten powders during hot isostatic pressing with a 3D multi-particle FEM approach

In this paper, hot isostatic pressing (HIPing) process of pure tungsten powders was numerically reproduced using multi-particle finite element method (MPFEM) at a particulate scale level. The effects of pressure, temperature and particle size ratio on the densification behavior of the tungsten powders during HIPing were systematically investigated. Various macro-and microscopic properties including relative density, overall/local stress distributions, deformation status, pore filling behavior and densification mechanisms were characterized and analyzed. The results show that the HIPing process of tungsten components can be numerically realized from particulate scale by properly controlling the HIPing conditions such as pressure and temperature. The pressure and temperature during HIPing play a dominant role in determining both the final properties of the compacts and the microscopic properties of individual particles. Also, different particle size ratios of the tungsten powder mass can affect both the macro-and microscopic properties of the compacts during and after HIPing. It is indicated that MPFEM modelling used in this paper can effectively conquer the deficiencies in physical experiments and traditional FEM modelling on the HIPing of refractory tungsten metals, which can provide an effective way to reproduce the HIPing process and identify the densification dynamics and mechanisms more accurately and realistically. (C) 2019 Elsevier B.V. All rights reserved.