Application of Infrared Thermography technique for the monitoring of Cold Metal Transfer (CMT) joining of aluminium to galvanized steel

摘要

In this study, the feasibility of using non-contact Infrared thermography as a potential tool to monitor the CMT welding process is explored. The presence of internal defects such as porosity, lack of filler material deposition and formation of improper weld bead produce perturbations in the surface temperature which can be identified using an Infrared thermography technique. We present recent results obtained from online monitoring of the dissimilar joining using CMT weld brazing of aluminium and steel using a transmission mode measurement approach. The effect of loss of zinc coating on the weldability of the cold metal transfer joining of aluminium to galvanised steel was investigated. A correlation between measured online thermal indications with the weld anomalies is successfully attempted and the results are compared with the conventional post-weld NDT inspection methods.