电阻点焊熔核形核信息的声发射信号表征

Characterization of nugget nucleation information by acoustic emission signals during resistance spot welding

摘要: 以结构负载压电传感的方式,研究借助声发射信号表征电阻点焊铝合金过程的熔核形核信息,包括焊接过程的声发射信号表征和熔核质量信息的声发射信号表征.结果表明,电阻点焊不论是稳定形核还是非稳定形核均可以用声发射信号来表征熔核形核的不同物理阶段.熔核形核的飞溅、开裂等特征事件也可以利用电阻点焊过程声发射信号的形核声发射特征参数来予以界定.声发射特征参数与熔核形核尺寸、焊点拉剪载荷具有较好的相关性.可以使用焊接过程中的声发射特征参数作为检测或预测熔核形核尺寸和焊点拉剪载荷的依据之一.

Abstract: The information of nugget nucleation during resistance spot welding of aluminum alloy was characterized the acoustic emission with the piezoelectric sensor,and the information of nugget nucleation includes the information of the welding process and that of nugget quality.The experiment results showed that,the different physical phases of nugget nucleation can be characterized by acoustic emission signal regardless of stable nugget nucleation or unstable nugget nucleation during resistance spot welding.The characteristic parameters of acoustic emission signal have a good relevance with nugget size and weld strength,and can be used to measure or predict the nugget dimensions and weld strength.