Dynamic deformation behavior of 93W-5.6Ni-1.4Fe heavy alloy prepared by spark plasma sintering

In this study, split Hopkinson pressure bar was used to evaluate the dynamic deformation behavior of the 93W-5.6Ni-1.4Fe heavy alloy (93WHA) prepared by spark plasma sintering (SPS) and conventional liquid-phase sintering (CLS). The influence of the microstructural characteristics (such as W grain size, W-W contiguity and volume fraction of the matrix) on the dynamic deformation behavior was investigated. In contrast to the conventional liquid-phase sintered 93WHA, the spark plasma sintered 93WHAs exhibit high yield strength and flow stress during high strain rate compression, due to the decreased mean matrix thickness (the mean matrix thickness is related to the W grain size, W-W contiguity and volume fraction of the matrix). The decreased matrix mean thickness and increased number of grain boundaries in the spark plasma sintered 93WHAs result in an increase of aspect ratio of W grains in the core of the deformed specimen and a decreased width of shear band along the direction of maximum shear stress.