Shock propagation in a cemented tungsten carbide

Abstract

WC-based ceramic metal composites ͑cermets͒ are of great importance in both armor and munition design due to the combination of properties imparted by the presence of two different phases. WC-Co cermets are of interest in this area due to the hardness and strength imparted by the WC phase while the cementing Co matrix acts to increase plasticity and toughness. Here the dynamic response of G13 WC-Co manufactured by Kennametal Engineered Products B.V. was studied via a series of plate impact experiments involving both longitudinal and lateral gauges, which allowed determination of the U s − U p relationship, measurement of a Hugoniot elastic limit of 3.3Ϯ 0.2 GPa, measurement of a spall strength of 4.38 GPa, and an investigation of the stress dependence of shear strength in such a strong material.

On the importance of encapsulation environment for lateral gauges

“…However, this is an inherently invasive approach, complicating interpretation. Recent computational modelling by Winter and Harris [8,9] and Winter et al [10] has highlighted on-going debate within the shock physics community [2][3][4][5][6][8][9][10][11]. In these works, the complexity of the embedded gauge environment was studied and a potential link between perceived changes in strength behind the shock and shock dispersion between the encapsulation and target material was demonstrated.…”

“…Approaches to lateral gauge inclusion have ranged from direct encapsulation in a castable target material to inclusion in a groove machined into the sample [4][5][6][7]. However, the most common approach involves gauge placement within an epoxy layer (encapsulation) in the centre of a target (matrix) sectioned along the impact axis [2][3][4][5][6]8]. However, this is an inherently invasive approach, complicating interpretation.…”

“…(1), knowledge of σ Y can provide insight into strength evolution both at, and following, shock arrival [1][2][3]. Approaches to lateral gauge inclusion have ranged from direct encapsulation in a castable target material to inclusion in a groove machined into the sample [4][5][6][7].…”

Experimental and computational investigation of lateral gauge response in polycarbonate

“…This was tentatively interpreted as an increase in strength due to viscoplastic behaviour. While a variety of approaches have been adopted [4][5][6][7], typically, gauges are placed within an epoxy layer (encapsulation) in the centre of a target (matrix) sectioned along the impact axis [2][3][4][5]. However, inclusion of this interlayer is inherently invasive, complicating interpretation.…”

“…As a time resolved diagnostic, Eq. (1) provides insight into strength evolution both at, and following, shock arrival [2,3].…”