钢铝混合后地板总成的自冲铆连接性能研究

通过子午线剖面组织分析和拉伸-剪切试验分析,对钢铝混合后地板总成的自冲铆连接性能和失效模式进行了研究。结果表明,板材的搭接组合方式对自冲铆接头的子午线剖面组织特征、拉伸剪切性能以及失效模式产生明显影响。当底层材料为AlSi10Mg高压铸铝,接头的残余底厚(tmin)以及底层互锁长度(a)较大;当底层材料为HC340/590DP高强度钢,接头的tmin和a值较小。接头的失效模式可分为3类,铆钉与上板分离、铆钉腿与下板分离以及上层板材断裂。所有接头的子午线剖面特征值以及拉伸-剪切性能均满足企业标准,因此,自冲铆接可实现钢铝混合后地板总成的焊装。

Research on Properties of Self-Piercing Riveted Connections for Aluminum-Steel Rear Floor Assembly

The properties and failure modes of self-piercing riveted connections were investigated for the aluminum-steel rear floor assembly by using the tensile-shear test and microstructure analysis of the meridian cross section.The results show that the lap joints of sheets play an important role in the meridian crosssection microstructure,tensile-shear properties and failure modes.When the bottom sheet is high pressure die-cast AlSi10 Mg alloy,the bottom material thickness(tmin)and the interlock(a)are much larger than those when the bottom sheet becomes the high-strength steel HC340/590 DP.Three types of joint failure are observed,i.e.the separation between the rivet and the upper sheet,the separation between the rivet leg and the bottom sheet,and the fracture of upper sheet.The cross-section characteristic values and tensile-shear properties of all the joints meet the industry standard.Therefore the rear floor assembly could be achieved by self-piercing riveting.