Weld Formation and Microstructure Evolution of High Power and High-Speed Laser Welded In-situ ZrB2p/6061Al Composites [原位 ZrB2p/6061Al 复合材料的大功率高速激光焊接成形和组织演变]

作者：Yu B.; Guo J.; Zeng Y.^*; Xia L.; Hu Y.; Li Z.; He Y.

来源：Rare Metal Materials and Engineering, 2022, 51(9): 3409-3418.

• laser welding
• mechanical properties
• microstructure
• ZrB2 particle

The 5wt%ZrB2p/6061Al composite was prepared by in-situ synthesis and the microstructure of laser welding and mechanical properties were studied. XRD and EDS analysis results show that 5wt%ZrB2p/6061Al composites are successfully prepared by the Al-K2ZrF6-KBF4 in-situ reaction system. By OM and SEM analysis, compared with the matrix 6061Al alloy, the heterogeneous nucleation effect and pinning effect of the nano ZrB2 particles has a certain grain refinement effect on the matrix grains of the composite, but the existence of nanoparticle clusters makes the refinement effect limited. During laser welding, under the condition of complete penetration, a high-power and high-speed welding of 3.6 kW and 40 mm/s can be utilized to obtain a well-formed weld. The rapid laser melting process and solidification make the matrix grains further refined, a large number of ZrB2 clusters basically disappear, and ZrB2 particles are basically evenly dispersed. By analyzing the migration behavior of ZrB2 particles, it is found that the melt agitation and rapid solidification process of the laser molten pool achieve the twice distribution of ZrB2 particles. The optimization of the weld microstructure improves the Vickers hardness (HV) and the tensile strength of the welded joint, up to 561.54 MPa and 125.17 MPa, respectively. And the strengthening mechanism of weld was discussed.

• 单位
  南昌航空大学