1999 Volume 23 Issue 1_2 Pages 394-396
Magnetostriction has been measured on commercial plycrystalline Fe+27%Co from room temperature to about 600°C using unbonded strain gages and a high- temperature mounting cement. The gage is excited at 1 kHz, and the sample driven around its hysteresis loop to a maximum field of about 200 Oe in a tune less than 15 seconds to minimize the strain due to temperature drift. Room temperature magnetostriction values agree reasonably well with those quoted by Bozorth (30 to 40 microstrain), and remain almost constant up to at least 350°C and sometimes higher, depending on the heat treatment of the sample. It therefore seems clear that stress-magnetostriction anisotropy will be significant in these alloys at high temperatures.