深冷处理和温度对Fe-Mn合金阻尼性能的影响

EFFECTS OF DEEP-COOLING AND TEMPERATURE ON DAMPING CAPACITY OF Fe-Mn ALLOY

通过测定Fe-Mn合金的层错几率以及借助G—L位错脱钉模型,研究了深冷处理和温度对其阻尼性能的影响。进一步揭示了Re-Mn合金的高阻尼机制.采用倒扭摆测试合金的阻尼性能、SEM观察显微组织、XRD测定物相体积分数和层错几率.结果表明,Fe-Mn合金的高阻尼机制与Shockley不全位错的脱钉运动相关;深冷处理增加了合金的层错几率,即增加了Shockley不全位错数量。阻尼性能得到提高;升高温度降低了Shockley不全位错的脱钉力,在一定应变振幅下,温度越高可以产生脱钉的Shockley不全位错数量就越多,合金的阻尼性能升高.

In order to disclose the high damping mechanism of Fe-Mn alloy, the effects of deepcooling and temperature on damping capacity were studied by measuring stacking fault probability and using G-L dislocation model. The damping capacity was measured using reversal torsion pendulum. The stacking fault probabilities and volume fraction of e-martensite were determined using XRD and the microstructure was observed using SEM. The results indicated that the high damping mechanism is resulting from the movement of Shockley partial dislocations. Because deep-cooling increases the stacking fault probability in γ-austenite and ε-martensite, the number of Shockley partial dislocations also increases and the damping capacity of Fe-Mn alloy is improved. Temperature rising can decrease the unpinning stress between Shockley partial dislocation and weak pinning points, therefore, with increasing the temperature, the number of unpinning Shockley partial dislocations increases and the damping capacity of Fe-Mn alloy is improved at a certain strain amplitude.