Abstract
Effect of faying surface treatment on the tensile shear strength (TSS) of joints has been studied in the weld of aluminum alloy (0.8t 5052) to mild steel (0.8t SPCC) using uni-directional weld current from SPCC to 5052.
Welded joints had 380 kg/spot TSS under the condition of wire-brushing on both SPCC's and 5052's faying surfaces. Slightly reduced TSS value was obtained under the condition of wire-brushing on SPCC's faying surface alone. But on the contrary, wire-brushing on 5052's faying surface alone, gave TSS value merely about 100 kg/spot. Therefore, to give wire-brush or not on SPCC's faying surface before the weld affects strongly on TSS of joints. Further, peeled fracture surface of the joint was observed by scanning electron microscope and it was found that joints under SPCC wire-brushing showed ductile deep dimple region while the other presented relatively flat bisttle face.
The above mentioned results indicate that the surface treatment of metals with higher melting point is important in the welding of dissimilar metals.
