Gr/Cu基SMA复合材料的阻尼行为

运用气压渗流法制备出了宏观石墨颗粒增强的形状记忆合金样品, 并利用多功能内耗仪对材料的阻尼行为进行了研究。发现在内耗-温度谱上有2个内耗峰, 分别出现在160 ℃和325 ℃左右。经分析后认为, 低温峰由孪晶细化引起, 高温峰则为马氏体相变峰。石墨颗粒加入后, 材料的相变内耗峰降低, 但背底内耗提高, 即材料的整体阻尼本领提高。根据测量结果, 对材料可能的阻尼机制进行了讨论。

Damping Behavior of Gr/Cu-based SMA Composites

Specimens of SMA reinforced by macroscopic graphite particles were prepared by pressure infiltration process.The damping behavior of the composite was investigated as well.It was found that two internal friction peaks presented on the curves of the internal friction against temperature at around 160 ℃and 325 ℃, respectively.The low-temperature peak originated from the fining of twin variants, while the high-temperature one from the phase transition from the parent phase to martensite.Although the net heights of the two peaks decreased, the background internal friction significantly increased with the introduction of macroscopic graphite particles into the alloy.Based on the experimental results, the correlatedmechanisms were discussed in detail.