抄録
The measurements of internal friction Q−1 under tensile loading and of mechanical properties have been carried out for open-melted Fe–Mo alloys containing 0∼16% Mo. The Q−1 values at a frequency of 0.3∼1.1 Hz linearly increase with the maximum shear strain amplitude εm and decrease after reaching a peak at εm=about 1.2×10−4. The peak height gradually diminishes with increasing tensile load. The Q−1 values are as small as 0.5×10−3 in the cold-worked state, whereas they are considerably large in the annealed state and increase with annealing temperature. The highest Q−1 value of 58×10−3 is obtained with an Fe-6% Mo alloy annealed at 1200°C for 1 h.
The results obtained indicate that Q−1 increases with temperature in the range of 20∼600°C and decreases rapidly with the increase in external magnetic field. The fairly large value of Q−1 in these alloys are mainly due to the effect of magnetomechanical hysteresis. The mechanical strength of Fe–Mo alloys increases with Mo content; for example, an Fe-6% Mo alloy shows a tensile strength of 390 MPa and a yield strength of 200 MPa, an elongation of 29% and Vickers hardness 135, when subjected to annealing at 1000°C for 1 h.
