嵌入式铝/钢带材轧制复合铝层和钢层厚度的变化规律

Thickness variation of aluminum layer-steel layer of embedded aluminum-steel composite strip during cold roll bonding

采用冷轧复合法制备嵌入式铝/钢复合带材,研究了嵌入式铝/钢带材冷轧复合压下率、铝带初始厚度对轧制复合变形区内铝层和钢层厚度比变化的影响规律;采用切片法计算变形区内界面剪切应力分布,分析了铝层和钢层厚度比变化的原因。结果表明:在特定压下率(r_(con))条件下,从轧制入口到出口变形区铝层与钢层厚度比呈先减小后保持基本不变的变化趋势;当压下率r<r_(con)或r>r_(con)时,铝层和钢层厚度比(RA/S)呈先减小后增加的变化趋势;当初始铝带厚度由0.50 mm减小至0.10 mm时,r_(con)由45%减小至30%;随着压下率的增加,变形区界面剪切应力增大,该剪切应力使铝层与钢层之间发生相对滑动(r<r_(con))、无相对滑动(r=r_(con))和粘着流动(r>r_(con));仅当压下率r>r_(con)时,拉伸断口铝层与钢层不分层,复合带材具有良好的界面结合状态。

The embedded aluminum-steel composite sheet was prepared by cold roll bonding(CRB) process.The influences of rolling reduction and initial thickness of aluminum strip on the thickness ratio of aluminum-steel in the deformation zone were investigated.The interfacial shear stress distribution in the deformation zone was calculated and the thickness variation of aluminum layer and steel layer was explained.The results show that the thickness ratio of aluminum-steel(RA/S) in the deformation zone from entrance to exit initially decreases and then remains unchanged under certain reduction r_(con).While the reduction is higher or lower than r_(con),RA/S initially decreases,and then increases.When the initial thickness of aluminum strip reduces from 0.50 mm to 0.10 mm,r_(con) decreases from 45% to 35%.With the increase of reduction,the interfacial shear stress increases,resulting in that relative sliding(reduction<r_(con)),non-relative sliding(reduction=r_(con)) and adhesive shearing(reduction>r_(con)) occur successively on the interface of the aluminum and steel layer.The composite strip has a good interfacial bonding quality,and there are no delamination of aluminum layer and steel layer on the tensile fracture when the reduction is higher than r_(con).