The effect of growth rate on the structure of primary and secondary dendrites of single crystal of Ni based superalloy

Abstract

So far, in our work aimed at obtaining single crystals of a Ni based superalloy, we have investigated the possibilities of obtaining single crystals using different methods as well as the influence of growth conditions, seed structure and abrupt changes in the growth rate (from lower to higher and from higher to lower) on the structure of the obtained single crystals. Using our experimental data, we have made an attempt to show whether there is a dependence between the growth rate (R), temperature gradient (G) and the distance between the primary dendrites (lambda(1)) of the following type lambda(1)=A.G(-m).R-n, and to establish the value of n. We have commenced a research on the influence of the growth rate, and its change during the experiment, on the distance between the secondary dendrites (lambda(2)) and their shape and size.