Effect of swaging on microstructure and tensile properties of W–Ni–Fe alloys

• Swaging of liquid phase sintered high density 90W-7Ni-3Fe and 93W4.9Ni-2.1Fe alloys led to considerable increase in tensile strength with reduction in ductility.
• In comparison to liquid phase sintered high density samples, swaging (15%) led to increase in contiguity values in both longitudinal and transverse directions.
• Swaging led to more severe deformation at the edges than at the center of the specimens.

The objective of this study was to investigate the effect of swaging on the microstructure and tensile properties of high density two phase alloys 90W–7Ni–3Fe and 93W–4.9Ni–2.1Fe. Samples were liquid phase sintered under hydrogen and argon at 1480 °C for 30 min and then 15% cold rotary swaged. Measurement of microstructural parameters in the sintered and swaged samples showed that swaging slightly increased tungsten grain size in the longitudinal direction and slightly decreased tungsten grain size in the transverse direction. Swaging increased the contiguity values in both longitudinal and transverse directions. Swaging led to more severe deformations at the edges than at the center of the specimens. Solidus and liquidus temperatures of the nickel-based binder phase in the sintered and swaged samples were determined by differential scanning calorimetry measurements. An increase in tensile strength with a reduction in ductility was observed due to strain hardening by swaging.