Structure and properties of W-Ni-Fe-Co heavy alloys compacted from nanopowders

Abstract

Heavy tungsten alloy (HTA) W-Ni-Fe-Co nanopowders synthesized by a chemical-metallurgical method are used to produce a compacted material with a theoretical density and a grain size of 2.9–4.6 μm. Upon solid-phase sintering (SPS) at 1350–1450°C, the binder composition of the produced material coincides with the binder composition of the alloy fabricated by liquid-phase sintering (LPS) according to a traditional technology. The hardness of the material is 4400–3400 MPa (as compared to 1750 ± 50 and 2950 ± 50 MPa after LPS followed by a hardening treatment for a standard HTA), and its ultimate tensile strength after SPS is 950–1050 MPa (as in the case of the standard alloy after LPS). The melting temperature of the binder is 25–30°C lower than that of the traditional alloy.