超高强钢/铝合金热铆连接接头性能

Joint performance analysis on connection of ultrahigh-strength steel and aluminum alloy with hot riveting

提出了热铆接淬火(Hot riveting quenching,HRQ)无铆钉铆接技术,可有效解决车身超高强钢与铝合金异种材料零件的连接问题。通过建立22MnB5超高强钢和7075铝合金HRQ无铆钉铆接有限元模型,以接头抵抗拉伸载荷的能力作为判断接头力学性能的标准,研究了模具参数和工艺参数对接头力学性能的影响。从对凸模半径R_t、凹槽半径r_a及凹模深度h_a等参数的优化和铆接接头的有限元单向拉伸仿真和试验中发现,在铆接成形温度T=700℃,凸模行程为5.3mm的成形条件下,无铆钉铆接接头力学性能强度最好。同时可得出接头所能承受的载荷主要与铆接接头的颈厚值相关,颈厚值的大小决定了铆接点处所受单向拉伸力的大小。

To solve the connection technique for ultrahigh-strength steel 22 MnB5 and aluminum 7075 sheets,aprocess called Hot Riveting Quenching（HRQ）clinching to connect autobody parts of ultrahigh-strength steel and aluminum alloy dissimilar materials is proposed.By using the good formability at elevated temperature and quenchability of steel 22 MnB5,effective joints between steel22 MnB5 and 7075 aluminum alloy are obtained by HRQ clinching.The feasibility of HRQ is confirmed by the formation and quenching finite element models.The punch radius Rt,die radius ra and depth ha are optimized by study of the connecting joint shape.The uniaxial tension finite element analysis and actual tests of the connecting joint show the connecting joints have the best mechanical properties when the forming temperature is 700 ℃ and the punch stroke is 5.3 mm.