Research On Roll Bonding Process Of Ni/Al Clad Strip

Ni/Al clad strip is a kind of high-quality composite materials,which has many advantages as electrical conductivity and stain resistance.It is widely used as Battery pole ear and has a good development prospects.Due to simple operation,high efficiency and low cost,the roll bonding technology is one of the most commonly methods to produce composite board at present.Reasonable control of the rolling process and annealing process,you can get high-quality Ni/Al composite board.In the experiment,producing composite board uses the"surface treatment-roll boding-heat treatment"three steps method to investigate the effects of rolling process and annealing process on the composite plate.The Ni/Al interface strength,the Ni hardness and the interface change are analyzed by metallographic microscope,Vickers hardness tester,scanning electron microscope,electron probe and electronic universal stretching machine.Research shows:(1).When the amount of deformation is 65.4%,the two metal plates can not achieve compound;when the deformation is 78.7%,the two metal plates can be compounded,but Ni surface is poor quality.So it is difficult to obtain a high quality Ni/Al composite sheet by the cold rolling method.(2).When the rolling temperature is lower than 300℃,the critical deformation of the composite plate is relatively large.So it is difficult to realize the composite.When the rolling temperature is 450℃,the oxidation temperature is too high that leads the quality of the composite plate to worse;In the rolling temperature of 300℃～400℃and the deformation of 40%～60%condition,the two metal plates can achieve composite and good shape.So this experiment is mainly used by hot-rolled composite process.(3).When the temperature is constant,the bonding strength of the composite plate increases with the increase of the deformation amount.When the deformation amount is constant,the low temperature rolling composite plate has high bonding strength.Therefore,the rolling temperature of 300℃anf the deformation of 53.1%are the appropriate rolling process parameters.(4).The annealing process can significantly improve the bonding strength of Ni/Al composite plate,and also reduce the hardness of Ni layer.The composite plate with rolling temperature of 300℃ and deformation of 53.1%is annealed at 460℃ for 60min.It’s bonding strength of the composite plate can increase to 64MPa,which can meet the strength requirement of the composite plate.It’s hardness decrease to 78.4HV,which also can meet the hardness value of the conditions.(5).When the annealing temperature is lower than 460℃ the intermetallic compound of NiAl3 is only detected in the composite interface,which can increase the interfacial bonding strength in a certain thickness.wh en the annealing temperature is higher than 460℃,the intermetallic compound of NiAl3 and Ni2Al3 can be detected in the composite interface.The growth of NiAl3 is mainly accept by bulk diffusion and grain boundary diffusion.It’s growth law is complex.Howover,the growth of Ni2Al3 showes a parabolic law,which is controlled by bulk diffusion.