Injection molding of nano-structured90W-7Ni-3Fe alloy powder
prepared by high energy ball milling①
prepared by high energy ball milling①
(The State Key Laboratory for Powder Metallurgy, Central South University,
Changsha 410083, P.R.China)
Changsha 410083, P.R.China)
Abstract: Blended elemental 90W-7Ni-3Fe (mass fraction, %) powder was mechanically alloyed in a planetary ball mill. Nano-crystalline grains were obtained after 10 h milling. The nano-structured powder was processed to full density by metal injection molding approach. Compacts from the optimal powder-binder mixture were studied for molding and sintering behaviors. Milling significantly increases the maximum powder loading and homogeneity of the feedstock, and enhances the sintering densification process. When solid-state-sintered at 1 350~1 450℃, the alloy shows very fine grains (~3μm), high tensile strength (>1 130 MPa) and almost no distortion.
Key words: tungsten heavy alloy; nano-structured powder; injection molding