Fabrication of Porous Ti-rich Ti sub(51)Ni sub(49) by Evaporating NaCl Space Holder

Net-shaped porous Ti-rich Ti sub(51)Ni sub(49) alloy with well-controlled porosity, pore size, and pore shape are fabricated by pressing-and-sintering compacts containing fine Ti and Ni powders and coarse NaCl powders. After sintering at 1323 K (1050 degree C) for 30 minutes in a high vacuum, the NaCl space holder is removed by evaporation, and the remaining Ti and Ni powders are sintered with about 2.3 vol pct liquid phase. The sintered Ti sub(51)Ni sub(49) compacts have porosities of 26, 64, 70, 78, and 85 pct, and no distortion is observed. DSC tests show that the M sub(S) temperature and Delta H are about 347 K (74 degree C) and 28 J/g, respectively, and that they are almost independent of the porosity and close to those of wrought Ti-rich TiNi alloys. These porous Ti sub(51)Ni sub(49) compacts exhibit a homogeneous microstructure, and the compressive properties and porosity are close to those of human bones.