Study on the Microstructure and Property for T-Joints of Al-Li Alloy Welded by Double Sided Synchronization Fiber Laser

Abstract:

In the experiment, the T-joints of 2060-T8/2099-T83 Aluminum-Lithium by double sided synchronization Fiber laser welding with thickness of 2 mm was studied aimed to know the microstructure, the distributions of micro-hardness, and the tensile strength of the T-joints. The results show that the microstructure is columnar fine grain zone, dendrite zone, and equiaxed crystal zone in turn from the weld fusion line to weld centre; the micro-hardness of the weld is lower than the micro-hardness of base metal, and softening phenomenon appears in the weld; The average circumferential tensile strength of T-joints is 423 MPa at room temperature, which reaches the strength of the base metal 82%, the average longitudinal tensile strength of T-joints is 449 MPa, which reaches the strength of the base metal 87%; The fracture of circumferential tensile samples initiates at the weld toe, and breaks in the weld centre or heat affected zone. The fracture of longitudinal tensile samples initiates at varying cross-section, there are dimples in the fracture surfaces of both circumferential tensile samples and longitudinal tensile samples, and the fracture is ductile.

• Periodical: Advanced Materials Research (Volume 1095)
• Pages: 859-864
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1095.859
• Online since: March 2015
• Authors: En Guang He, Li Chen, Ming Tao Wang
• Keywords: 2060 Aluminum-Lithium Alloy, Circumferential Tensile of T-Joints, Double Sided Synchronization Fiber Laser Welding, Longitudinal Tensile of T-Joints

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