• Chinese Journal of Lasers
  • Vol. 50, Issue 24, 2402103 (2023)
Yuqi Zhou1, Lihong Chen1, Jianfeng Wang1, Zhu Li2, Zhan Mu2, and Xiaohong Zhan1、*
Author Affiliations
  • 1College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, Jiangsu , China
  • 2Xi’an Gangyan Special Alloy Co., Ltd., Xi’an 710000, Shaanxi , China
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    DOI: 10.3788/CJL230861 Cite this Article Set citation alerts
    Yuqi Zhou, Lihong Chen, Jianfeng Wang, Zhu Li, Zhan Mu, Xiaohong Zhan. Research on Microstructure Evolution and Tensile Properties of Laser Welded Joints of Domestic Invar Alloy[J]. Chinese Journal of Lasers, 2023, 50(24): 2402103 Copy Citation Text show less
    Schematics of laser welding. (a) Laser welding; (b) molten pool morphology
    Fig. 1. Schematics of laser welding. (a) Laser welding; (b) molten pool morphology
    Schematics of sampling position and size of specimen. (a) Sampling position; (b) size of tensile specimen
    Fig. 2. Schematics of sampling position and size of specimen. (a) Sampling position; (b) size of tensile specimen
    Weld morphologies under different heat inputs. (a)(a1)(a2) Low heat input (90 J/mm); (b)(b1)(b2) medium heat input (150 J/mm); (c)(c1)(c2) high heat input (200 J/mm)
    Fig. 3. Weld morphologies under different heat inputs. (a)(a1)(a2) Low heat input (90 J/mm); (b)(b1)(b2) medium heat input (150 J/mm); (c)(c1)(c2) high heat input (200 J/mm)
    Effect of heat input on molten pool dimension. (a) Schematic of typical molten pool; (b) corresponding dimensions under different heat inputs
    Fig. 4. Effect of heat input on molten pool dimension. (a) Schematic of typical molten pool; (b) corresponding dimensions under different heat inputs
    Microstructures under different heat inputs
    Fig. 5. Microstructures under different heat inputs
    Schematics of microstructure growth conditions during molten pool solidification process. (a) Constitutional supercooling condition; (b) expansion stage of columnar grains; (c) formation stage of equiaxed grains; (d) weld grain distribution
    Fig. 6. Schematics of microstructure growth conditions during molten pool solidification process. (a) Constitutional supercooling condition; (b) expansion stage of columnar grains; (c) formation stage of equiaxed grains; (d) weld grain distribution
    IPFs, PFs, and distribution histograms of grain sizes and misorientation angles under different heat inputs
    Fig. 7. IPFs, PFs, and distribution histograms of grain sizes and misorientation angles under different heat inputs
    Sub-grain structures at WS bottom and secondary dendrites at centerline of WS under different heat inputs. (a)(d) Low heat input (90 J/mm); (b)(e) medium heat input (150 J/mm); (c)(f) high heat input (200 J/mm)
    Fig. 8. Sub-grain structures at WS bottom and secondary dendrites at centerline of WS under different heat inputs. (a)(d) Low heat input (90 J/mm); (b)(e) medium heat input (150 J/mm); (c)(f) high heat input (200 J/mm)
    Tensile test results of weld seam under different heat inputs. (a) Stress-strain curves; (b) tensile strength and elongation
    Fig. 9. Tensile test results of weld seam under different heat inputs. (a) Stress-strain curves; (b) tensile strength and elongation
    Fracture morphologies under different heat inputs. (a) Low heat input (90 J/mm); (b) medium heat input (150 J/mm); (c) high heat input (200 J/mm)
    Fig. 10. Fracture morphologies under different heat inputs. (a) Low heat input (90 J/mm); (b) medium heat input (150 J/mm); (c) high heat input (200 J/mm)
    ElementNiMnSiAlTiCFe
    Mass fraction /%36.0400.3500.1800.0470.0660.023Bal.
    Table 1. Chemical compositions of domestic Invar alloy
    No.Laser power P /(W)Welding speed v /(m·min-1

    Heat input /

    (J·mm-1

    122501.590
    230001.5150
    330001.2200
    Table 2. Laser welding process parameters of domestic Invar alloy
    Yuqi Zhou, Lihong Chen, Jianfeng Wang, Zhu Li, Zhan Mu, Xiaohong Zhan. Research on Microstructure Evolution and Tensile Properties of Laser Welded Joints of Domestic Invar Alloy[J]. Chinese Journal of Lasers, 2023, 50(24): 2402103
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