Microstructure and Tensile Behavior of Laser Arc Hybrid Welded Dissimilar Al and Ti Alloys

Abstract

Fiber laser-cold metal transfer arc hybrid welding was developed to welding-braze dissimilar Al and Ti alloys in butt configuration. Microstructure, interface properties, tensile behavior, and their relationships were investigated in detail. The results show the cross-weld tensile strength of the joints is up to 213 MPa, 95.5% of same Al weld. The optimal range of heat input for accepted joints was obtained as 83–98 J·mm−1. Within this range, the joint is stronger than 200 MPa and fractures in weld metal, or else, it becomes weaker and fractures at the intermetallic compounds (IMCs) layer. The IMCs layer of an accepted joint is usually thin and continuous, which is about 1μm-thick and only consists of TiAl2 due to fast solidification rate. However, the IMCs layer at the top corner of fusion zone/Ti substrate is easily thickened with increasing heat input. This thickened IMCs layer consists of a wide TiAl3 layer close to FZ and a thin TiAl2 layer close to Ti substrate. Furthermore, both bead shape formation and interface growth were discussed by laser-arc interaction and melt flow. Tensile behavior was summarized by interface properties.

Fiber Laser Welding of Dissimilar 2205/304 Stainless Steel Plates

“…Components with adequate ductility, high strength, good corrosion resistance, and desirable electrical and thermal conductivities have been achieved through DM welding [3,4]. Several DM welding techniques have been reported, including Welding-Brazing [5][6][7], Arc [8][9][10], Friction [11], Friction stir [12,13], Ultrasonic [14,15], Explosive welding [16], Laser [17][18][19], and Hybrid Laser-Arc welding [20,21].…”

FEM Simulation of Dissimilar Aluminum Titanium Fiber Laser Welding Using 2D and 3D Gaussian Heat Sources

“…The increment in the HAZ of aluminum was due to the dissolution of magnesium compounds during the welding cycle [30]. A layer of intermetallic compounds (IMC) formed between the two fusion zones (Figure 9), whose stoichiometry was clarified in some paper [26,31,32]. This layer is due to the reaction in the temperature of the two alloys, and the size is variable as a function of the process parameters [32].…”

“…For both 2D and 3D heat source modeling, a complete penetration of keyhole was obtained, and, particularly for the 2D heat source, the boundary of the fusion zone obtained numerically had similar shapes in comparison with the experimental ones. A layer of intermetallic compounds (IMC) formed between the two fusion zones (Figure 9), whose stoichiometry was clarified in some paper [26,31,32]. This layer is due to the reaction in the temperature of the two alloys, and the size is variable as a function of the process parameters [32].…”

“…Particularly for the welding process parameters concerning this study, the average thickness of the IMC layer was equal 50 ± 5 µm to and the average nanohardness value (0.01/15) was equal to 2485 ± 232. A layer of intermetallic compounds (IMC) formed between the two fusion zones (Figure 9), whose stoichiometry was clarified in some paper [26,31,32]. This layer is due to the reaction in the temperature of the two alloys, and the size is variable as a function of the process parameters [32].…”

“…A layer of intermetallic compounds (IMC) formed between the two fusion zones (Figure 9), whose stoichiometry was clarified in some paper [26,31,32]. This layer is due to the reaction in the temperature of the two alloys, and the size is variable as a function of the process parameters [32]. Particularly for the welding process parameters concerning this study, the average thickness of the IMC layer was equal 50 ± 5 µm to and the average nanohardness value (0.01/15) was equal to 2485 ± 232.…”