Microstructure variations and their effect on the magnetic properties of a single die-cast Nd60Fe30Al10 alloy rod

Microstructure and magnetic properties for an as-quenched, single rod (3 mm diameter, 50 mm length) of Nd60Fe30Al10 alloy obtained by copper mold casting technique, were characterized on three different zones along the rod length selected at the bottom, middle and upper part. The bottom part was in direct contact with an additional copper plate, while the upper part was located at the open side of the copper mold. A predominant amorphous microstructure was found at the bottom part of the rod for which maximum intrinsic coercivity of 3519 Oe was observed, while a magnetically decoupled composite structure was established at the opposite rod side, together with a noticeable reduction in coercivity (down to 3070 Oe). Results are interpreted on the basis of increasing crystalline volume fraction from bottom to the upper part of the alloy rod.