An Experimental Study on Self-resistance Welding of CFRTP

Abstract

In this study, a new welding method which utilizes conductivity of CFRTP (Carbon fiber reinforced thermoplastic) is proposed. Electrical current is applied through the CFRTP single-lap joints in thickness direction. Since resistance of joining surface is the highest in the current path, the joining surface is preferentially heated by Joule heating. In this study, spot welding and surface welding were conducted. By applying constant voltage of 5.0V or ,10.3V, the joint-surfaces were heated above melting temperature, Tm of the material and were welded. In order to evaluate lap-shear strength (LSS) of welded joints, tensile lap-shear tests were conducted. As a result, the tensile lap-shear true stress of spot welding is 31.0MPa and LSS of surface welding is 22.0MPa. These strengths were comparable to those that were welded by traditional resistance welding. It is also found that LSS is changed with welding pressure of joint parts.