Thermal and structural analysis of ultrasonic-welded PC/ABS blend for automobile applications

PC/ABS thermoplastic blends are widely employed in manufacturing sectors, as it yields good mechanical behavior when subjected to dynamic loading conditions. While investigating the fundamental nature of PC/ABS blends, ultrasonic welding process appears to suit their joining as compared to other conventional techniques. This paper focuses on PC/ABS welding using ultrasonic and the subsequent investigation from the insight of thermal science. It is imperative for the materials to retain key properties after subjecting it to welding. Examinations to evaluate these properties through DSC reveal a lower onset temperature change and a small variation of glass transition temperature, respectively, for parts which indicate minimal changes in thermal properties in welded and non-welded specimens. Apparent activation energies determined from TG data are practically independent of heating rates, which suggests that the most important process in the degradation of these materials corresponds to ABS. Those mixtures with high PC content show a clear increase in apparent activation energies with heating rate, suggesting that the thermal degradation mechanism of these samples is composed of several complex processes, each predominant during different stages of the overall process. SEM is used to investigate the structural morphology of the welded parts.