Effect of nickel interlayer thickness on lap joint laser welding for aluminium-steel dissimilar materials

Abstract

Laser lap welding of steel and aluminium with different thickness nickel foil was carried out. The effects of nickel interlayer thickness (T Ni ) on penetration depth, phase transition, mechanical properties were investigated. As the T Ni increased from 0 to 50 µm, the weld penetration depth was first increased and then decreased, reaching a maximum of 382 µm when T Ni was 20 µm. There was a γ -phase transformed from δ-ferrite in welded nugget and the transformation of high-temperature δ-ferrite into austenite was promoted as the T Ni increased. The shear resistance of the steel/Al joint reached the maximum value of 103 N mm −1 when T Ni was 20 µm. Which was almost 92% higher than the strength of the joint without nickel foil added.

Investigating parametric effects during TIG welding of dissimilar metals

“…In a separate study, Xue-long CAO assessed the characteristics of the laser welding joint between the 6061 Aluminium alloy and 304 stainless-steel. This involved the use of varied laser parameters and Copper Nickel interlayers [17]. It was determined that finetuning the thickness of the Cu interlayer to 0.02 mm led to a significant increase in the shear force, which rose to 1350.96 N.…”

“…Tianyu Xu investigated the effect of nickel foil thickness on laser welding of Aluminium and steel lap joint. Using a nickel foil of 20µm thickness can extend the penetration depth to 382µm and enhance shear resistance to 103N/mm, marking a 92% rise compared to joints devoid of the nickel foil [17].…”

Microstructural evaluation in dissimilar liquid phase bonding of cast Al–Si alloy and stainless steel using pure zinc filler metal

“…low toughness Al 5 Fe 2 ) at the joint interface are the critical metallurgical challenges during dissimilar joining of Al/steel. The presence of brittle intermetallic compounds at the joint interface coupled with the creation of thermal stress induced by a significant thermal expansion mismatch between Al and steels during joining leads to the high susceptibility of Al/steel dissimilar joint to cracking [1][2][3][4].…”

“…Solid-state welding processes such as friction stir welding are viable candidates for dissimilar welding of Al and steels [4][5][6][7]. In addition, some metallurgical joining processes, such as resistance spot welding [1,8,9], laser welding [2], arc welding [10], laser/arc hybrid [3], etc., enable Al/steel dissimilar joining via establishing a liquid/solid interface during joining. In these cases, the formation of intermetallic compound (IMC) due to solid steel-liquid Al reaction is the outstanding challenge to achieve a strong bond.…”

Microstructure and Mechanical Properties of Stainless Steel/6082 Aluminum Alloy Heterogeneous Laser Welded Joint

“…Chen et al [18] found that, by placing a layer of nickel foil interlayer made of 99.9% nickel between the laser welded plates of 201 stainless steel and 5052 aluminum alloy with a CO 2 laser-focused spot diameter of 0.2 mm, compared to the joints without nickel foil, the fracture area of the IMCs of the joints with added nickel foil was significantly reduced. Xu et al [19] added different thicknesses of nickel interlayer in SUS202 stainless steel and 2A12 aluminum alloy and studied the effect of different thicknesses of nickel interlayer on the mechanical properties and microstructure of welded joints. The results showed that, due to the addition of nickel, the melting of steel to aluminum was promoted, and the tensile strength of the welded joints was up to 103 N/mm when the nickel interlayer was 20 µm, and is improved by the addition of a nickel intermediate layer.…”