MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF HOT-PRESSED NI3AL-BASED INTERMETALLIC POWDER PRODUCED BY ROTATING ELECTRODE PROCESS

Rapidly solidified powder of Ni3Al intermetallic compound modified with Fe, Ti and B was produced by a rotating electrode process (REP). The obtained powder has a mean particle size of 400 mum, spherical shape and very narrow size distribution. The powder was compacted by hot pressing to non-porous, homogeneous compacts with an average grain size of 50 mum. The yield strength shows positive temperature dependence with the maximum at 600-degrees-C. The ductility decreases moderately with temperature to the minimum at 600-degrees-C, and then abruptly increases. The results of this work show that the mechanical properties of the hot-pressed Ni3Al-based powder produced by REP are better than or at least comparable to nickel-aluminides obtained by advanced consolidation techniques (hot isostatic pressing, hot extrusion).