The Effect of Laser Offset Welding on Microstructure and Mechanical Properties of 301L to TA2 with and without Cu Intermediate Layer

Abstract

Based on dissimilar materials of 301L/TA2, the effect of laser offset and copper intermediate layer on welded joints was investigated. First, the process optimization of laser offsets indicated that the tensile strength of welded joint without intermediate layer was reached to the highest value when the laser was applied on the TA2 side. On the other hand, the tensile strength of welded joint with intermediate layer performed well when laser was applied in the middle position. Then, microstructural characterization and mechanical properties of welded joints were observed and tested. Based on eutectic reaction and peritectic reaction: TiFe and TiFe2 compounds were produced for welded joint without intermediate layer. Cu-Fe solid solutions and Cu-Ti compounds were generated when copper was used as the intermediate layer. The maximum tensile strength of welded joint with and without copper intermediate layer were 396 and 193 MPa, respectively. Finally, fracture mechanism of 301L/TA2 welded joint was studied: Fe-Ti compounds caused brittle fracture of welded joints without intermediate layer; brittle fracture took place in rich copper and Cu-Ti compounds area of welded joints with copper intermediate layer.

The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates

“…This observation is in line with other research findings, e.g., [ 23 ]. The dissimilar laser welding of DP steels studied in the literature [ 31 , 32 , 33 ] also formed the fusion zone with nonuniform microstructure in each part of the weld, which corresponds to the chemistry during laser welding.…”

“…The fusion zone in Figure 6c was mainly composed of acicular ferrite microstructure, bainite, and martensite, which had different sizes and shapes. This observation is in line with other research findings, e.g., [23]. The dissimilar laser welding of DP steels studied in the literature [31][32][33] also formed the fusion zone with nonuniform microstructure in each part of the weld, which corresponds to the chemistry during laser welding.…”

“…The disadvantages of laser welding are low-energy efficiency, strict requirements for the purity of working gases (CO 2 , nitrogen, and helium), and material thicknesses up to about 2 mm for solid-state and diode lasers [ 20 ]. However, laser welding enables the joining of two dissimilar materials, as described by several authors [ 21 , 22 , 23 ].…”

Pulsed Laser Welding Applied to Metallic Materials—A Material Approach

“…Since the materials have different physical and thermal properties, some properties significantly affect the interaction with the laser beam, influencing the performance of the process. For this reason, the melting temperatures, thermal expansions, heat capacities, and thermal conductivities could be considered during the selection of materials [46][47][48][49][50]. For numerous engineering applications, joining two different materials is essential to achieve the necessary component characteristics.…”

Interfacial Microstructure of FeCoNiCrAl0.1 High Entropy Alloy and Pure Copper Prepared by Explosive Welding

“…Secondly, during the welding process, the atoms of dissimilar metals will undergo strong mutual diffusion under the action of high temperature. Therefore, during the cooling process, a large amount of brittle and hard intermetallic compounds may be formed in the welded joint [6]. Finally, the heat introduced during the welding process makes the material being welded more sensitive to intergranular corrosion and solidification cracks [7].…”