铝箔力学性能的实验研究

Experimental Research of Mechanical Properties for Aluminum Foil

铝箔已被广泛应用于电子工业,现又被用作锂电池正极集流体,因而对于铝箔的力学性能要求也在不断提高。通过表征和研究铝箔的力学性能(弹性模量、屈服强度、断裂强度等),能够为铝箔相关技术的可靠性研究提供必要的数据支持和理论指导,从而使铝箔得到合理和可靠的使用。本文运用微拉伸、纳米压痕和动态力学分析(DMA)实验,分别研究了不同厚度的H18态和O态铝箔的力学性能。结果表明两者的弹性模量均约为30GPa,仅为块材的一半;H18态铝箔材料的断裂强度要明显强于块材,而O态铝箔材料的断裂强度则明显小于块材;此外,H18态铝箔材料的屈服强度明显大于块材,O态铝箔材料的屈服强度与块材相仿。并且,随着厚度的增加,H18态铝箔材料的延伸率显著增大,但是仍远小于块材。通过扫描电子显微镜(SEM)对铝箔材料断裂形貌进行微观分析,发现铝箔的拉伸断裂方式为脆性断裂。

Currently,aluminum foil has been widely applied in electronic industry and in lithium battery as positive electrode current collector,therefore,the requirement for aluminum foil mechanical properties is continually increased.Necessary data support and theoretical guidance can be provided for reliability study related with aluminum foil technology through understanding and characterizing aluminum foil basic mechanical properties such as elastic modulus,yield strength,and fracture strength etc,so that the aluminum foil can be used reasonably and reliably.In this paper,mechanical properties of H18-state and O-state aluminum foils with different thicknesses were experimentally studied by using micro tension,nanoindentation and dynamic mechanics analysis（DMA）.Results show that elastic modulus of both H18-state and O-state aluminum foils is approximately 30 GPa,which is only half of the bulk material.Fracture strength of H18-state aluminum foil is significantly stronger than the bulk material,while O-state aluminum foil is significantly smaller than bulk material.In addition,yield strength of H18-state aluminum foils is obviously stronger than that of bulk material,while O-state aluminum foils is similar with the bulk material.With the increase of thickness,elongation of H18-state aluminum foil increases obviously,but still far less than the bulk material.Fracture morphology microscopic analysis of aluminum foil by using scanning electron microscope（SEM）finds that aluminum foil tensile fracture mode is a kind of brittle fracture.