Properties of high density tungsten-rhenium alloys by liquid phase sintering

This paper reviews out several past studies on modified, high strength tungsten heavy alloys produced by liquid phase sintering. Emphasis is given to the W-Re alloys, because of the high density and strength possible in this system. In this paper, the sintered density, hardness, strength , and ductility are reported versus the composition and microstructure. At relatively low alloying levels, Re additions reduce the solution-reprecipitation kinetics associated with liquid phase sintering, giving strengthening via microstructure refinement and solid solution alloying. The Re modified alloys exhibited a smaller grain size, higher hardness, higher strength, and lower ductility than the unalloyed system. For a composition of 84W-6Re-8Ni-2Fe, the sintered density was 17.4 g/cm3 with a yield strength of 815 MPa, tensile strength of 1180 MPa, and elongation to failure of 13%. In the unalloyed system, these properties require post-sintering swaging and aging. The results using rhenium additions are compared with previously reported experiments using molybdenum additions