High Power CO2 Laser Aluminum Tailored Blank Welding

Aluminum tailor welded blanks in the automotive industry continues to grow due to the light weight of aluminum itself and the characteristics of the tailor welded blanks. It has been found that welding of aluminum blanks with co₂ laser is difficult but doable in a production environment and using high power CW Nd:YAG laser can obtain sound results with a much wider process parameter window. However, currently, high power CO₂ lasers (in the range of 8 kW) are still the dominate laser sources in steel tailor welded blank companies in north America. Will these lasers be able to weld aluminum tailored blanks if the demand of aluminum tailor welded blanks increases? This study employed twin spot and beam shaping methods to weld 1mm combined with 2 mm tailored blanks using high power (9 kW maximum) CO₂ laser for both 5754-O and 6111-T4 alloys. The results show that high power CO₂ lasers can be used for welding 5754-O and 6111-T4 aluminum alloys with very precise parameter settings. However, using beam shaping is more critical than using twin spot for 1 mm thick aluminum blanks. But, once the correct parameters are applied for using beam shaping, the cup test results are better than using twin spot