Effect of Ti content on weld formation and mechanical properties of welded joints of TA2/Q235 bimetallic sheets

Abstract

Due to the issue of brittle Ti-Fe intermetallic compounds, a challenge for the welding of Ti/steel bimetallic sheets is presented. In this study, four types of multi-principal powders of Fe₂₅-_xCo₂₅Ni₂₅Cu₂₅Ti_x were designed based on eutectic high-entropy alloys (HEAs), which were used as filler materials for laser welding of TA2/Q235 bimetallic sheets. The impact of Ti content in the filler powders on weld formation and mechanical properties was investigated. It is found that with an increase in the Ti content, the hardness values of the weld zones generally increased, whereas the tensile strengths decreased. The maximum tensile strength of ∼298.4 MPa was achieved in the joint using Fe₂₀Co₂₅Ni₂₅Cu₂₅Ti₅ filler powders, in which the weld metal met the definition of an HEA.