Evaluation of Welding Properties of Metallic Foil with an Electron Beam

Abstract

For the fabrication of MEMS or devices in micro scale, joining of small parts is a critical issue. In this study, thin metal foils were welded using electron beam welding to investigate the weldability of the foils. In the welding of thin foils, the heat-affected zone and welding state are strongly dependent on the energy density of the irradiation beam, and size effects, such as heat capacity and stiffness, are important as the thickness of the material becomes small. Two materials, stainless steel and titanium with thickness values of 10 μm and 20 μm, were used as workpieces. An electron beam with several incident energies was applied, and the surfaces and cross-sections of the weld zones of the workpieces were examined. The experimental results show that the weldability of foil welding strongly depends on the material properties and the thickness of the workpieces, and it becomes more difficult to weld two overlapping foils with smaller thickness and lower thermal conductivity.