Microstructure and Mechanical Properties of Copper/304 Stainless Steel Joints Welded by Laser Beam

The Copper/304 stainless steel joints with a thickness of 5mm are fabricated by disk laser, the microstructure and mechanical properties of the laser beam welded Copper/304 stainless steel joints are investigated. Results show that the microstructure of the weld is dominated by austenite matrix when the offset distance of laser beam is -0.2~0 mm, and the Cu-rich phase embedded in the austenite matrix of the weld is glo-bular and filiform and the weld crack expands along filiform Cu-rich phase embedded in the austenite. The microstructure of the weld is dominated by Cu matrix when the offset distance of laser beam is 0.2~0.4 mm, and the number of filiform Cu-rich phase embedded in the austenite decreases and the occurrence of the weld crack is effectively inhabited. The Fe-rich phase embedded in the Cu matrix of the weld is mainly globular, and has a small amount of dendrites when the offset distance of laser beam is -0.2~0.4 mm. The welded joints fracture in the copper HAZ when the offset distance of laser beam is -0.2~0.2 mm, the tensile strength and the elongation of welded joints can reach 95.6% and 39.3% of those of the copper base metal respectively. The welded joints fracture in the weld metal when the offset distance of laser beam is 0.4 mm, the tensile strength and the elongation of welded joints are 71.9% and 23.6% of those of the copper base metal respectively. © 2019,Materials Review Magazine. All right reserved.