Welding characteristics of Ag-based contact material under automobile lamp load

The welding characteristics of different contact pairs, which are made up of AgNi10, AgNi0.15 or AgSnO/sub 2/, under an automobile lamp load are investigated. The appearance of contact surfaces and composition distribution over the welding area are studied by means of a scanning electron microscope and electron probe. The results have shown that the welding area consists of a melting area and welding points. The welding points are distributed over the melting area. The rupture mode of the welding points is ductile fracture and the fractured surfaces are characterized by a heavily dimpled appearance. The composition of the welding points is almost the same as that of the anode material for the asymmetrical pairs. The welding performance is influenced significantly by anode material.