INFLUENCE OF JOINING TIME ON MICRO STRUCTURE AND MECHANICAL PROPERTIES OF TLP-JOINED IN-738LC TO GTD-111

摘要

Influence of joining time on microstructural and mechanical characteristics of IN-738LC joined to GTD-111 using TLP process and with MBF-20 filler was studied. Joining process was performed at 1100°C in a vacuum condition and for various durations of 5, 30 and 60 minutes. Microstructural observations were performed using optical microscopy, SEM and EDS. It was shown when required time for isothermal solidification is not met; deleterious inter-metallic and eutectic compounds would form on the joining center-line. Moreover, the nature of eutectic structures formed during isothermal solidification process could be changed by varying bonding time. It was also found that the mechanical properties of the bond is highly dependent on the amount of inter-metallic and eutectic compounds formed in the joint area, so that when no inter-metallic compounds are formed, the highest strength values could be reached.