Effect of Fe₂O₃ nanoparticle on the interface microstructure and properties of Al/Cu plasma arc fusion-brazing joints

The lap joint of T2 copper plate and 1060 pure aluminum plate was made by using the plasma arc welding method with adding Fe₂O₃ nanoparticles in different proportions. The research analysis found that the thickness of the IMC (intermetallic compound) and eutectic region decreased after the addition of nanoparticles due to its inhibitory effect. When the proportion of Fe₂O₃ nanoparticles is 3%, the interface intermetallic compound layer is the thinnest. However, after this ratio is continuously increased, the inhibition effect is weakened by the agglomeration of nanoparticles, and the thickness begins to increase significantly. The mechanical and electrical properties of the joint are mainly affected by the thickness of the IMC layer. Excessive nanoparticles are agglomerated into large particles with high resistivity. Therefore, the tensile strength and relative electrical conductivity of the joint are first increasing and then decreasing with the increase of nanoparticle ratio. When the proportion of nanoparticles is 3%, the tensile strength and electrical conductivity are maximum.