Dynamic mechanical characterization and optimization of particle-reinforced W-Ni-Fe composites

Abstract

A visco-plastic rate-dependent homogenization theory for particle-reinforced composites was derived and the equivalent elastic constants and the equivalent visco-plastic parameters of these composites were obtained. A framework of homogenization theory for particle-reinforced W-Ni-Fe composites, a kind of tungsten alloy, was established. Based on the homogenization theory and a fixed-point iteration method, a unit cell model with typical microstructures of the composite was established by using dynamic analysis program. The effects of tungsten content, tungsten particle shape and particle size and interface strength on the mechanical properties and the crack propagation of the W-Ni-Fe composite are analyzed under quasi-static and dynamic loadings. The stress-strain curves of the composite are given and the relation between the macro-mechanical characteristics and the microstructure parameters is explored, which provides an important theoretical basis for the optimization of the W-Ni-Fe composites.W-Ni-Fe composite, dynamic mechanical property, microstructure, homogenization theory, optimization PACS: 46.50.+a, 02.60.Pn, 62.20.Mk W-Ni-Fe particle-reinforced composite is a kind of tungsten alloy with tungsten and other metal elements such as nickel, iron, Cu, Co, Mo, and Cr, sintered at high temperature. It consists of tungsten particles with (bcc) structure embedded in nickel-iron bonding phase grid with (FCC) structure. Tungsten alloy has the following characteristics: high density, high strength, high melting point and high hardness; good resistance to corrosion resistance and high temperature oxidation; good ability to absorb radiation; good electrical conductivity, good thermal conductivity, and low coefficient of thermal expansion [1]. W-Ni-Fe composites have been widely used in national defense, aerospace and civil applications due to the good mechanical properties. In the aerospace field, the application of high-density tungsten alloy in the gyroscope has made rapid progress for navigation technologies. In the weapons industry, tungsten alloy is used as core material for large caliber kinetic energy penetrator and long-rod kinetic energy penetrator. In the nuclear industry, tungsten alloy is ideal for fuel storage containers and radiation shielding materials. In the civilian industry, tungsten alloy can be produced as mechanical tool handles, mechanical hands, drill bits, etc.Researchers have done a lot of work on the testing technologies, dynamic responses, dynamic failure of materials and micro-mechanism of fracture for W-Ni-Fe composites [2][3][4][5]. Rittel and Weisbrod [6] studied the static and dynamic fracture toughness in three distinct orientations using short beam experiment technique and found that the quasi-static fracture toughness is relatively isotropic and rate insensitive, while the dynamic fracture toughness is markedly anisotropic and rate sensitive. Rabin and German [7] conducted tensile tests at room temperature and found that the flow stress increased and the fracture strain decreased ...

Oblique penetration of tungsten alloy rod to finite-thickness metal plate

“…The main parameters of Johnson-Cook strength model for tungsten alloy and homogeneous armor steel (Verreault, 2015;Couque et al, 2007;Luo et al, 2016;Song and Ning, 2011;) are shown in Table 2. The fragments have obvious statistical characteristics of probability, because the fragments are random when the projectile is broken, but the structure and material of the projectile are uniform and the material properties are unique in numerical simulation.…”