孕育剂Ti和Zr元素对2219铝铜合金焊缝组织和性能的影响

Effect of inoculants Ti and Zr on microstructure and mechanical properties of 2219 Al-Cu alloy welding

采用5种焊丝对2219铝铜合金进行MIG焊,研究了孕育剂Ti和Zr元素对焊缝组织和性能的影响.结果表明,Ti和Zr元素的细化作用是相容的,当焊丝中单独添加孕育剂Ti或Zr元素时,焊缝几乎由粗大的柱状晶组成.焊丝中复合添加少量的孕育剂Ti和Zr元素时,Ti和Zr元素在熔池中分别形成Al3Ti和Al3Zr,促进了α(Al)非均质形核.随着焊丝中Ti和Zr元素含量的增加,焊缝组织逐步细化.当焊丝中Ti和Zr元素含量较高时,Ti和Zr元素还在熔池中形成大量的Al3(Ti,Zr)质点,促进α(Al)非均质形核,焊缝组织由细小均匀的等轴晶组成,显著提高了接头强度和塑性.

Metal inert gas(MIG)welding was used to weld 2219 Al-Cu alloy with five kinds of filler metal,effect of the inoculants Ti and Zr additions in filler wires on the microstructures and properties of weld metal was investigated.The results showed that Ti and Zr was compatible,grain structures of weld were coarse columnar grains with a little Ti or Zr in filler wires,Al3Ti and Al3Zr were formed in the welding pool with additions of a little Ti and Zr in filler wires,which provided the heterogeneous nucleation sites for α(Al).The grain of the microstructure of weld metal was finer with the increasing of Ti and Zr compositions in filler wires.Intermetallic aluminized dispersoids Al3(Ti,Zr)were formed in weld metal with additions of large amounts of Ti and Zr in filler wires,which accelerated the heterogeneous nucleation of α(Al)and resulted in refining grains of the weld metal,so the tensile strength and elongation of weld joint were increased.