Development of a new high-density iron-tungsten alloy (FWA) reinforced by Fe7W6 and Fe2W particles with high tensile strength and specific strength

Abstract This paper develops a new type of high-density iron-tungsten alloy (FWA) with high hardness and tensile strength by adding 15.6 wt% W into DT300 steel. The microstructure of FWA is characterized by separated network-like Fe7W6 around the grain boundary of ɑ-Fe matrix and nano-scale fine Fe2W particles are evenly distributed in the ɑ-Fe matrix, with some dispersive SiO2 particles. The new FWA has higher elastic modulus, micro-hardness, and tensile strength compared to DT300 steel. The micro-hardness and tensile strength of the FWA are 716.6 HV and 1267.7 MPa, which are approximately 18.1% and 6.5% higher than those of DT300 steel, respectively. The specific strength of new FWA is 1.49*105 (N/m2)/(kg/m3), which is 1.8–4 times higher than that of tungsten heavy alloys. The high strength of FWA is attributed to the strengthening of the multiscale iron-tungsten intermetallic compound.