3D particulate-scale numerical investigation on hot isostatic pressing of W-Cu composites

The hot isostatic pressing (HIP) of W-Cu composite powders with different compositions and size ratios was numerically reproduced by using 3D multi-particle finite element method (MPFEM) from particulate scale. The effects of temperature, pressure, mass fraction of Cu particles as well as Cu/W size ratio on the densification behavior of W-Cu compacts were systematically discussed. The macroscopic property such as relative density and various microscopic properties such as stress/strain distributions of W and Cu particles, strain rate, contact normal force, densification mechanisms and so on were quantitatively characterized and analyzed. The results indicate that the higher temperature induces Cu particles to having a more significant decrease in the equivalent Von Mises stress than W particles, leading to a larger difference of the equivalent total strain and the equivalent plastic strain rate between W and Cu particles; also, the contact normal force of particles in the cluster is smaller when the temperature is higher. The size ratio has no obvious effect on the equivalent stress distribution of W and Cu particles. While the smaller the size ratio, the larger the equivalent total strain of Cu particles, resulting in a larger difference of equivalent total strains between W and Cu particles, and the smaller the normal contact force of Cu particles in the cluster. The mass fraction of Cu particles can significantly affect the compressibility of W-Cu compacts. The smaller the mass fraction of Cu particles, the lower the relative density and the greater the total strain energy of the W-Cu compact. The plastic deformation of Cu particles caused by the synergetic action of temperature and pressure is the main reason for its densification mechanism.