| High-density tungsten alloys have been widely used in civilian industry and military industry because of their excellent physical-mechanical characteristic. However, the performance of high-density tungsten alloys can't been improved in further due to the high sintering temperature and the long holding time of conventional sintering method, which can not inhibit the W grain growth. Spark plasma sintering(SPS), as a novel electric current sintering method, can restrain efficiently the grain growth by reducing sintering temperature and holding time owing to the effect of cleaning and activating on particle from high pulsed electric current. So this method provides an efficient path for preparing high-density and fine grain tungsten alloys. For this reason, SPS technique was used to preparing W-8.6Ni-4.2Fe alloys in this paper. The main research work was as follows.SPS technique was used to preparing W-8.6Ni-4.2Fe alloys from mixed powders. The influences of the sintering temperature and the holding time on the density, hardness, transverse rupture strength and compressive strength were studied. When the sintering temperature was 1250℃and the holding time was 6min, the best combination properties of as-sintered alloy were achieved. The relative, hardness, transverse rupture strength and compressive strength were 97.7%, 42 HRC, 1443 MPa, and 2639 MPa, respectively. The combination properties of as-sintered alloys would decrease at other sintering temperatures and holding times.High-energy ball milling was used to prepare W-8.6Ni-4.2Fe powders, and then these milled powders were sintered by SPS. The effects of milling time and sintering temperature on density, hardness, transverse rupture strength and compressive strength were mainly studied. There existed intermetallic compound NiW and Fe7W6 existed besides hard phase W and binder phaseγ(Ni,Fe) in the as-sintered alloys. The hardness increased, but the density, transverse rupture strength and compressive strength decreased when prolonging the holding time. Elevating sintering temperature, the density increased and the hardness decreased, but the transverse rupture strength and compressive strength were increased at first and then decreased. The effects of sintering temperature, holding time, and milling time on the tribological properties were also studied. When the holding time remained invariant, wear-resisting property of the materials was getting better, and the wear mechanism gradually changed from abrasive wear to adhesive wear with elevating sintering temperature. If the sintering temperature was a fixed value, wear-resisting property of the materials was gradually improved with prolonging the holding time, and the adhesive wear was the dominate wear mechanism. When prolonging the milling time, wear volume loss increased at first and then decreased. And the milling time had few influence on surface morphology of wear scar.The hot compression test was performed, and the effects of the deformation rate, the deformation temperature, and the preparation process on mechanical property of the as–sintered alloys were studied. For as-sintered alloys from mixed powders, the compressive strength increased and the ductility decreased when enhancing deformation rate or lowering deformation temperature. When the deformation rate was 50 mm/min and the deformation temperature was 800℃, the alloy sintered at the temperature of 1200℃had the maximum strength 966 MPa. While for the alloys from milled powders, the compressive strength increased and the ductility decreased when enhancing deformation rate or lowering deformation temperature. The stress-strain curve was insensitive to variation of the sintering temperature. All the strength of the as-sintered alloys from milled powders were higher than those of as-sintered alloys from mixed powders, and the strength of the as-sintered alloys from milled powders could achieve 1850 MPa when the deformation rate was 0.2 mm/min and the deformation temperature was 600℃.
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