RELAXATION OF NONEQUILIBRIUM PHASE-STRUCTURE STATE OF NI3AL-BASED ALLOY STRIP CRYSTALLIZED ON ROLLING

A strip (thickness 200 mu m) of Ni3Al-based alloy with Cr, Mo, Zr, and B obtained by fast crystallization has a dendritic-cellular structure , with an incompletely ordered matrix and a high level of internal str ess, The material is characterized by high, but not stable, strength a t room temperature, as well as reduced plasticity and technological co nvenience, and the phase-transition temperature close to the solidus l ine is reduced because of the presence of unstable, readily fusible ph ases, High-temperature annealing (1000-1200 degrees C) eliminates this nonequilibrium structure, which leads to increase in low-temperature plasticity and the phase-transition temperatures on melting. The phase composition of the alloy is analyzed, and the composition and crystal line structure of the excess phases of carbide M6C, carbonitride Zr(C, N), boride M3B2, M3B4, and Ni20Al3B5, and intermetallide ZrAl1.5Mo0.5 type are determined.