Abstract
The galvanized steel sheet has been used widely in various fields. However, zinc, which has a low melting temperature, evaporates and penetrates into the joint during the conventional welding process, thus a low temperature welding process is required. Linear Friction Welding (LFW) is a solid-state joining process, which uses the friction heat generated at the interface when the materials are butted together. Recent studies reported that the welding temperature is lower at a higher applied pressure during the LFW. Therefore, this welding process is expected to suppress the evaporation of zinc. In this study, a galvanized steel sheet was welded by LFW at various pressures. The effect of the galvanization on the LFW process depends on whether the welding temperature is above or below the melting temperature of the zinc layer. The non-uniformity of the flash increased welding time, and zinc embrittlement cracking occur above the melting temperature. However, a high applied pressure prevents the melting of the zinc layer. As a result, zinc is discharged to the outside of the joint while remaining on the surface, and joints without defects can be successfully obtained.
