铆接方式对2A10铆钉镦头变形的影响

Influence of riveting methods on deformation of 2A10 rivet heading

为了探究不同铆接方式下铆钉的变形过程和变形机理,分别进行准静态压铆、低电压电磁铆接和高电压电磁铆接工艺试验,以2A10铆钉不同镦头变形量为切入点,对比分析了铆接方式对铆钉镦头微观组织的影响规律。结果表明,在准静态压铆条件下,铆钉镦头变形较均匀,随着变形程度的增加,各区域晶粒破碎数目增多,但未出现明显的绝热剪切带。高、低电压电磁铆接镦头均以绝热剪切方式变形,高电压下成形镦头的绝热剪切现象相对更明显。镦头变形量为0.625时,相比于低电压电磁铆接,高电压电磁铆接加载速率更高,集中变形区域更窄,绝热剪切带宽度由112.7μm降至91.6μm,且镦头中心区主剪切带内出现一条宽度为17.2μm的白亮带。

To explore the deformation process and deformation mechanism of rivet with different riveting methods,the process tests of quasi-static pressure riveting,low-voltage electromagnetic riveting and high-voltage electromagnetic riveting were carried out,respectively.Starting with the different heading deformation amounts of 2A10 rivet,the effect of riveting method on the microstructure of rivet heading was compared and analyzed.The results show that under the condition of quasi-static pressure riveting,the heading deformation of rivet is relatively uniform,and with the increase of deformation degree,the number of grain breakage increases,but there is no obvious adiabatic shear zone.Under the condition of high or low-voltage electromagnetic riveting,both the heading deformation of rivet are carried out by adiabatic shear,and the adiabatic shear phenomenon of heading is more obvious under high-voltage forming state.When the deformation amount of the heading is 0.625,the loading rate of high-voltage electromagnetic riveting is higher than that of low-voltage electromagnetic riveting,and the concentrated deformation area is narrower.The adiabatic shear band width decreases from 112.7μm to 91.6μm,and a white bright band with width of 17.2μm appeares in the main shear band of heading center.