Effect of high-gradient directed crystallization on the structure and phase composition of a high-temperature alloy of the type RENE-N5

A study of the effect of the conditions of high-gradient directed crystallization on the structure and phase composition of a high-temperature alloy of the RENE-N5 type is presented. It is established that high-gradient directed crystallization fully eliminates the formation of structural defects in the form of freckles and provides a homogeneous fine-dendrite structure with highly disperse segregations of a secondary hardening gamma '-phase with a perfect chemical composition and fragmented particles of a ( gamma + gamma ')-eutectic. High-temperature annealing induces the formation of t.d.p. phases in the alloy, which necessitates optimization of its chemical composition. For this purpose it is expedient to use high-gradient directed crystallization of the alloy, which improves its service characteristics.