【摘要】 采用DZ-3×63型三相次级整流式点焊机对1 mm厚2A12铝合金进行了点焊试验。通过焊接压力和锻压力的不同组合,研究焊接压力和锻压力对2A12铝合金点焊熔核裂纹的分布规律及形状尺寸的综合影响。结果表明:产生的裂纹一般是位于熔核内的纵向凝固裂纹。在电极下方中部、熔核边沿的热影响区,可能形成沿晶横向液化裂纹;在焊接压力一定的条件下,产生的裂纹数量和长度总体随锻压力的增大而减小;高强铝合金点焊时,焊接压力越大,锻压力也需相应增大。更多还原

【Abstract】 Spot welding experiment of the aluminum alloy 2A12 sheet with thickness of 1 mm was performed at the three-phase secondary rectification welding machine DZ-3×63. It studied the combined effect of welding pressure and forging pressure on the crack distribution law, shape and size of the aluminum alloy 2A12-T4 spot welding joint through different combination of welding pressure and forging pressure. The results showed that cracks generated in the nugget are normally longitudinal solidification crack. However, sometimes there is transverse liquation crack generating in the central region under electrode, which is the HAZ(heat-affected zone) near nugget edge. Under the condition of certain welding pressure, the number and length of cracks decrease with the increasing of forging force. For high strength aluminum alloy spot welding, the more welding pressure to be added, the more forging pressure needed to be increased accordingly.更多还原