预变形量对Fe-19Mn和Fe-19Mn-1.5Si合金阻尼性能的影响

采用倒扭摆法评价了Fe 19Mn合金和Fe 19Mn 1.5Si合金在不同预变形量下的阻尼性能，并通过光学显微镜和X射线衍射仪分析了合金的微观组织形貌和层错几率.结果表明：预变形量小于4%时，由于Fe 19Mn和Fe 19Mn 1.5Si合金的层错数量增加而使其阻尼性能提高；预变形量在4%~10%时，Fe 19Mn合金的层错数量不断增加，但由于马氏体和层错的相互交割严重、层错和马氏体变得短小以及Shockley不全位错的脱钉运动困难，致使其阻尼性能反而下降；而由于Fe 19Mn 1.5Si中Si具有固溶强化和降低层错能的作用，合金本身的马氏体和层错较小，预变形量对其影响不大，即变形不改变Shockley不全位错的脱钉难度，故其阻尼性能继续保持稳定增长.

Effect of Pre deformation on Damping Capacity of Fe-19Mn and Fe-19Mn- 1.5Si Alloys

The effect of pre deformation on damping capacity of Fe 19Mn and Fe 19Mn 1.5Si alloys was studied. The damping capacity was measured using reversal torsion pendulum with free decay method. The stacking fault probability was determined by means of XRD (X ray diffraction). The microstructure was observed using OM (optical microscope). The results indicate that with the tensile strain increasing (0%-10%), the stacking fault probability in γ austenite and ε martensite of Fe 19Mn alloy increases continually. When the tensile strain is above 4%, however, Shockley partial dislocations are cut into several segments because of the reciprocal chiasm of stacking faults and perfect dislocations gliding, so the distance of two strong points decreases. The damping capacity of Fe 19Mn alloy, therefore, is improved with the tensile strain increasing until it reaches maximum at 4%, and then decreases. But it is not the same regularity to Fe 19Mn 1.5Si alloy when tensile strain is above 4%. The ε martensite and stacking faults are small before deformation, so the pre deformation can not change the microstructure of Fe 19Mn 1.5Si alloy and the damping capacity does not decrease when tensile strain is above 4%, but is still increasing stably.