轧制对Mg-3Cu-1Mn合金温度阻尼峰的影响(英文)

Influence of rolling on internal friction peak of Mg-3Cu-1Mn alloy

经过变形量4.7%的单道次室温轧制变形,Mg-3Cu-1Mn合金的一次温度—阻尼谱出现了3个明显的阻尼峰;在二次温度—阻尼谱中,3个阻尼峰均发生变化,特别是第3阻尼峰P3受到抑制,变得非常不明显。对各阻尼峰峰温处淬火样品进行金相、XRD、EBSD等实验,研究轧制对Mg-3Cu-1Mn合金温度—阻尼峰的影响。结果表明:在一次温度—阻尼谱中的P3峰处出现织构增强、孪晶急剧消失的现象;轧制变形后,3个温度—阻尼峰依次为位错阻尼峰、晶界阻尼峰和孪晶引发的再结晶阻尼峰;另外,随着拉伸孪晶的消失,室温轧制态Mg-3Cu-1Mn合金的应变阻尼性能大幅度恢复,高应变下接近均匀化退火态Mg-3Cu-1Mn的应变阻尼性能。这说明拉伸孪晶对Mg-3Cu-1Mn合金应变阻尼性能有不利的影响。

The damping capacities of as-rolled Mg?3Cu?1Mn (CM31) alloy were studied by dynamic mechanical analyses. The internal friction in the first heating shows peaks P1, P2 and P3 at 118, 190, and 320 °C, respectively. The significant peak P3, which can not be found in the cast CM31 alloy, appears in the first heating Q?1 curve and disappears in the second heating Q?1 curve. The influence of rolling on the internal friction peaks of the CM31 alloy was investigated by optical microscopy, X-ray diffraction, and electron backscatter diffraction analyses. The results show that the textures are enhanced and the twins rapidly disappear while peak P3 appears after deformation of the CM31 alloy, and confirm that the three internal friction peaks are the dislocation damping peak, grain boundary damping peak, and the recrystallization peak caused by twins, in the as-rolled CM31 alloy.