铝冷轧加工表面的微裂纹分析

微乳液润滑的铝冷轧过程中常会在铝合金表面出现与轧制方向垂直的规则微裂纹．规则裂纹的产生是由于新生金属表层氧化膜与体相金属具有不同的拉伸性能．考虑氧化膜拉伸强度极限与其厚度、体相材料的屈服极限及边界润滑的摩擦系数等因素，建立了理论模型，预测微裂纹分布间隔．通过对两种不同轧机冷轧加工后的铝合金表面分析，验证了分析模型的正确性，研究结果将对铝冷轧特性的分析起到促进作用．

Analysis of micro-cracks of aluminium sheet surface during cold rolling process

Regularly distributed micro-cracks which are perpendicular to the rolling direction are usually formed on the surface of aluminium sheet during cold rolling lubricated with micro emulsions. Experiments show that micro-cracks occur after cold rolling process, which is attributed to various parameters, for instance, the thin oxide film formed at the sheet surface. The micro-crack spacing thus becomes an important parameter that should deserve more attention. By taking into consideration of the oxide fracture process, the aspect ratio of these micro-cracks is analyzed theoretically. The good agreement between the observations and the theoretical predictions validates these analyses. This approach can shed some new lights on the mechanical process of aluminium sheet during cold rolling.