抄録
The effect of cold working on the magnetic properties and the precipitation morphology of Co–Fe–Nb alloys has been investigated by means of hysteresis loop measurements and transmission electron microscopy.
The results obtained are summarized as follows:
(1) The solution treated and 50% cold rolled specimens show a peak value of coercive force when they are annealed at 800°C for 1 h. While, this peak occurs when the specimen heavily cold worked by 97.8% is annealed at 700°C for 1 h. The squareness ratio and the rectangularity increase as the cold working rate increases.
(2) In the solution treated and 50% cold rolled specimens, the precipitates are in the form of a thin platelet, while in the alloy is cold worked heavily by 97.8%, the precipitates become spherical. The structure of the precipitates is confirmed to be a hexagonal Laves phase Co3Nb.
(3) Magnetic hardening of the heavily cold worked alloy is attributed to the precipitation of spherical Co3Nb.
