The effect of water quenching on initial and maximum permeabilities, intensity of magnetization, magnetic hysteresis loss, coercive force and residual magnetic induction of iron-aluminium alloys has been measured with the forged and rolled specimend, and the relation between the changes and the quenching temperature or the alloying concentration have been studied.
For the alloys containing comparatively small amount of aluminium, no peculiar point has been found on the curve of those properties to the quenching temperature or the alloying concentration.
However, in considerably wide range of aluminium content of more than 8 percent, the curves of both permeabilities to the quenching temperature show a maximum portion extending over the range of 400° to 750°, which is caused by the existence of the new phase Fe13Al3.
For the alloys containing more than 11.6 percent aluminium, that is, in the Fe3Al superstructure range, the curves of both permeabilities to the quenching temperature show generally two maxima; it being considered that this is caused by the transformation mechanismus of the Fe3Al superstructure. And from this fact, it is easily understood that the existence of the superstructure may be the cause of the increasing of the permeabilities, as in the case of permalloy. The initial permeability of the alloy containing 13.92 percent of aluminium reaches 3500 when quenched from 550° and the maximum permeability of the alloy of 15.29 percent of aluminium, 34300 when quenched from 700°.
The effect of the quenching on the magnetic hysteresis loss, coercive force and the residual magnetic induction is inverse to the effect on the permeabilities. The smallest values of the loss and the coercive force are 70 ergs/cm3/cycle and 0.02 Oe respectively, and are obtained when the alloy containing 14.87 percent of aluminium was quenched from 750°.
The effect of the quenching on the maximum permeability of the rolled specimens is more remarkable than in the case of the forged specimens mentioned above. The greatest values of the initial and the maximum permeabilities were obtained with the alloy containing 15.84 percent of aluminium when quenched from 600°; they are 3100 and 54700 respectively.
Please do not copy without permission.