Carbide formation during laser welding of SiC/aluminum composites

Abstract

The critical thermal conditions for the formation of aluminum carbide during the laser welding of SiCp-Al metal matrix composites were studied. A combined experimental and analytical approach was employed. The experimental approach included laser welding experiments on the composites. Measurements of the thermal fields were made during laser processing and the weld profiles and aluminum carbide areas were characterized in the samples after laser treatment. The analytical model was based on Rosenthal’s line source solution obeying a modified Beer Lambert’s Law. The analytical model was calibrated with the help of experimental measurements and the calibrated model was then used to calculate the thermal fields within the weld region and to determine the critical conditions for aluminum carbide formation.Cooling rate was determined to be the most important factor for controlling the formation of aluminum carbide. It was determined that at a minimum formation temperature of 1100 K (827°C), the critical cooling rate for the formation of aluminum carbide during laser processing of Al-SiC composites was 12000 K/sec (12000°C/sec).The critical thermal conditions for the formation of aluminum carbide during the laser welding of SiCp-Al metal matrix composites were studied. A combined experimental and analytical approach was employed. The experimental approach included laser welding experiments on the composites. Measurements of the thermal fields were made during laser processing and the weld profiles and aluminum carbide areas were characterized in the samples after laser treatment. The analytical model was based on Rosenthal’s line source solution obeying a modified Beer Lambert’s Law. The analytical model was calibrated with the help of experimental measurements and the calibrated model was then used to calculate the thermal fields within the weld region and to determine the critical conditions for aluminum carbide formation.Cooling rate was determined to be the most important factor for controlling the formation of aluminum carbide. It was determined that at a minimum formation temperature of 1100 K (827°C), the critical cooling...