The wettability of each sample was quantified using the wetting characteristics (wetting length and angle) defined in Fig. 4. Where a loe wetting angle and long wetting length represent good wettability. measured for 3 specimens per case is summarized in Fig. 5. The galvanized steel samples showed better wettibility compared to the aluminized steel samples. These results occurred because the Zn layer improves the spreading and wetting of Al on the steel surface. An Al-Zn eutectoid was formed near the braze weld. Leading to a lower wetting angle compared to the Al filler metal alone. In the case of galvanized steel, the wettability was improved by the high Si content of the filler metal, which enhanced the fluidity of the molten pool; however, in the case of aluminized steel, the wettability was not affected by the filler metal.