Abstract
Welding of copper alloy and steel, such as stainless steel, involves a combination of high thermal conductivity and high mechanical strength, so it is expected to be used for heat exchangers or pipe arrangement. However, welding of copper alloy and steel is difficult, because copper and steel have different thermal properties, such as thermal conductivities and melting point. In addition, copper and iron, which hare the main constituents of steel, do not form an alloy. Here, laser butt welding of brass plate and stainless steel plate 1.5 mm in thickness was examined using a disk YAG laser. The bondable welding conditions were selected, and the structures of welded copper and stainless steel were evaluated by tension test, watertight test, EPMA, and X-ray diffraction. The results indicated good bond strength and water tightness when laser irradiation position was put in the brass side from 0.1 mm to 0.2 mm.
