Features of the structure of porous titanium nickelide during reaction sintering with an aluminum additive

Porous cylindrical samples of a titanium nickelide-based alloy containing 0.5, 1.5, and 2.0 at % Al of 2.5 x 30 mm in size were obtained by two-stage sintering. The first stage was solid-phase sintering at t a parts per thousand yen 900A degrees C, and the second stage was liquid-phase sintering at t > 1000A degrees C. Starting from existing notions of the reaction diffusion in the Ti-Ni-Al system, the structure of the obtained alloy is analyzed. It is established by scanning electron microscopy and electron probe microanalysis that a multiphase alloy is formed during the first sintering. This alloy contains isolated regions of the TiNi phase, the isolation of which prevents the propagation of the front of the martensite phase transformation in the ready sample. The heterophase structure of the Ti50Ni50 - x Al (x) porous alloy, which is formed after the first sintering, becomes more uniform after carrying out the second one at a higher temperature.