Influence of elastic stress on precipitation and magnetic properties of Fe-Ni-Al alloys

External elastic stress applied during the precipitation process of Fe-Ni-Al alloys influences the orientation of elongated precipitates. Compression of the crystal along the
\langle 100 \rangle
axis makes the orientation of elongated precipitates to this direction unfavorable. When compressive stress is applied along the
\langle 110 \rangle
axis, the rod-like precipitates are oriented mostly to
\langle 100 \rangle
axis which is perpendicular to the direction of compression. Uniaxial magnetic anisotropy induced during the thermomechanical treatment (cooling under stress) causes a considerable increase of permanent magnetic properties in comparison with those obtained without stress. The energy product
BH_{\max} = 2.1 \times 10^{6}
G.Oe is obtained on a single crystal of alloy free from cobalt.