The ultrathin miniaturized metal foil has high sensitivity to strain rate due to the size effect during microforming processes. The correlations between the strain rate, size effect and microformability are still unclear at the micro-nano-scale. Hence, the coupling influence mechanism of strain rate and foil thickness on micro-deformation behavior of ultrathin (<20 μm) TA1 foil is investigated through uniaxial tensile tests at room temperature. The macro-mechanical laws are described by the stress-strain analysis. Meanwhile, to better clarify the micro-mechanism of macro-mechanical response, EBSD analysis and molecular dynamics simulation were conducted to research the evolution of micro/nano structures and the fracture morphologies of the specimens after tensions were observed by SEM. The results indicate that the strain rate has significant effect on the microstructural evolutions of specimens with different thickness after uniaxial tensile. The investigation provides an in-depth understanding on the deformation mechanism of ultrathin miniaturized TA1 foil and promotes the application for improvement the formability of high-strength micro-components at room temperature.

由于微成型过程中的尺寸效应，超薄小型化金属箔对应变率具有很高的敏感性。在微纳米尺度上，应变率，尺寸效应和微成形性之间的相关性仍不清楚。因此，通过室温下的单轴拉伸试验研究了应变速率和箔厚度对超薄（<20μm）TA1箔微变形行为的耦合影响机理。宏观力学定律通过应力应变分析来描述。同时，为了更好地阐明宏观力学响应的微观机制，通过EBSD分析和分子动力学模拟研究了微观/纳米结构的演变以及在通过SEM观察张力后试样的断裂形态。结果表明，应变速率对单轴拉伸后不同厚度试样的显微组织演变有显着影响。该研究提供了对超薄小型化TA1箔的变形机理的深入了解，并为提高高强度微组件在室温下的可成形性提供了应用。