Deformation characteristics of the 93W–4.9Ni–2.1Fe tungsten heavy alloy deformed by hydrostatic extrusion

The microstructures evolution, the mechanical properties and the fracture characteristics of the 93W–4.9Ni–2.1Fe tungsten heavy alloys deformed by hydrostatic extrusion with an equal-strain contour concave die were investigated. The strengthening mechanism of the extruded specimens was characterized using a quantitative metallographical technology, scanning electron microscope and a 200 kV transmission electron microscope. Through the research it can be concluded that the increase of the dislocation density in tungsten grains and in matrix, the appearance of the sub-grains in tungsten grains, the decrease of the axial contiguity of the tungsten grains, the increase of the tungsten grain's cleavage proportion in fracture aspect of tungsten alloy are the main factors to strength tungsten alloy.