Nickel aluminide Ni3Al in the single phase form, with grain size similar to 10 mu m, porosity similar to 5%, tensile strength 425 MPa, modulus 92 GPa and ductility 9.5% at room temperature, was fabricated by reactive infiltration at 800 degrees C of liquid aluminium into a porous preform containing 78 vol% nickel and made by sintering 3-7 mu m size nickel particles. Without sintering, the preform contained 58 vol% nickel and reactive infiltration resulted in an aluminium-matrix NiAl3 particle (similar to 50 mu m size) composite and extensive growth of Ni-Al needles from the preform to the excess liquid aluminium around the preform.