GRAIN-GROWTH OF FE-AL WIRE FABRICATED BY THE LIQUID-METAL SPINNING METHOD

The grain growth behavior and the geometrical aspects of grain boundar ies in Fe-Al wire which was fabricated by the liquid metal spinning me thod (LMSM) were investigated with respect to grain size distributions and geometrical features of the grain boundaries. An improved method previously proposed by the present authors was applied to Scanning Ele ctron Microscopy-Electron Channeling Pattern (SEM-ECP) in order to cla rify the boundary characteristics. The present investigation showed th at grains initially smaller in size than the diameter of the wire grew up during heat treatments, and subsequently transformed into the ''ba mboo-like'' structure in which the grains were aligned one-dimensional ly along the wire direction. General boundaries were much more frequen tly observed than special boundaries after the heat treatments. Most o f the boundary planes which remained until the late stages of the heat treatments were asymmetric, i.e., they had two different sets of crys tallographic indices which were individually attached with two grains adjacent to each other. In the characterization of the tilt-twist comp onent of the grain boundaries, double peaks outstandingly appeared in the distribution curves. The mobility of the grain boundaries was not sensitive to the crystallographic symmetry of the boundaries.