【摘要】 研究了微孔金属薄膜的微观变化和阻尼性能,采用扫描电镜(SEM)原位观察实验方法对带孔金属薄膜微观结构和阻尼进行分析。分析得到:交变载荷拉伸加载过程中微纳米孔缺陷试件经历了微裂纹萌生、微裂纹扩展及多孔裂纹重叠等一系列变化过程,而卸载过程中,微裂纹逐渐消失。同时得出金属薄膜应变滞后于应力周期性变化的规律,并求出损耗因子为0.00442。结果表明:在交变载荷作用下,微孔附近微裂纹的萌生、扩展及多孔处裂纹叠加变化促使外载荷的机械能以热能形式散失,是金属薄膜具有一定的阻尼减振性能的原因之一。更多还原

【Abstract】 The microscopic changes and damping properties of porous metal films was studied,perforated metal thin film microstructure and damping were analyzed using scanning electron microscopy(SEM) in-situ observation method.It was obtained that the micro and nano-hole defects metal film experienced a series of changes such as micro-crack initiation,crack propagation and micro-porous crack overlapping in the loading process;And during the unloading process,the micro-cracks gradually disappeared.Meanwhile,the metal thin film strain lags behind the stress periodic variations and the loss factor of 0.00442 was obtained.The result shows that under alternating loads,the micro-crack initiation,crack propagation and micro-porous crack overlapping prompte the external load mechanical energy loss as heat,which is one of the reasons having damping properties of metal films.更多还原