The investigation of physical-mechanical properties of intermetallic Ni-Al catalyst with nanostructure

摘要

Intermetallic Ni3AI synthesized from mixtures of nickel and aluminum powders with subsequent applications of pressure is studied for its structure and temperature dependences of its mechanical properties during tensile, compression, torsion and bending tests. Potentialities to increase ductility and strength of this material are revealed. The yield point of the material at room temperature is 280 MPa. As the temperature rises, it increases monotonically, reaching a maximum (500 MPa) at 873 K. An analogous temperature dependence of the yield strength of cast NiAl3 stoichiometric composition. A nanostructure consisting of hexagonal plates with a diameter of about 2 μm and a thickness of 200-300 nm is formed on the surface. Plates are generally oriented perpendicular to the surface of the substrate on which they grow. Often they coalesce along the ribs, forming stars. There are also areas on which the plates coalesce along the faces, forming extended columnar structures.