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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2022, Vol. 43 ›› Issue (2): 625020-625020.doi: 10.7527/S1000-6893.2020.25020

• Special Topic of Advanced Aeronautical Materials Welding/Joining • Previous Articles     Next Articles

Interface microstructure and formation mechanism of oscillating laser brazed joints for aerial sensing elements

LI Haoyue1, LIU Yongjiang3, ZHAO Zhenxing3, LI Xueran3, JIANG Junjun2, WU Laijun1,2, TAN Caiwang1,2, SONG Xiaoguo1,2   

  1. 1. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China;
    2. Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology (Weihai Extension), Weihai 264209, China;
    3. Tianjin Aviation Electro-mechanical Co. Ltd, Tianjin 300308, China
  • Received:2020-11-27 Revised:2020-12-10 Published:2021-02-02
  • Supported by:
    National Natural Science Foundation of China (52005132, 51875129)

Abstract: The sensing element is the core component of the avionics sensing system, and the pin of the element is often needed to be welded to wires when in use. To further improve the stability and reliability of the product, the oscillating laser brazing technology is proposed to be used to realize the welding of the lead silver wire of platinum resistor and the multi-stranded copper wire. Under the condition that the laser CW continuous mode and the defocus distance of +10 mm remain unchanged, the laser power and scanning time could be adjusted within a certain range of adaptation by adjusting the process, which could avoid poor gap filling and excessive corrosion in the joint and finally obtain a reliable and defect-free joint. The interface structure mainly consisted of Cu-Ni solid solution, Cu-Zn phase, Ag-based solid solution, and typical Ag-Cu eutectic structure. The thermodynamic calculation results show that Cu and Zn atoms diffused mutually under the drive of chemical potential at the interface, and the Cu-Zn phase had a greater driving force for precipitation. Ag atoms diffused from the silver wire to the side of the copper wire, forming the typical Ag-Cu eutectic structure in the Ag-rich region.

Key words: oscillating laser brazing, silver wire, multi-stranded copper wire, interface structure, formation mechanism

CLC Number: