Laser process monitoring: The next generation approach in industrial application

Abstract

Laser materials processing is widely used in industry today. The quality of the produced parts is vital for the manufacturer and it is even more important to discover early in the manufacturing process if the required result can be met. ISO 9000 and other by law enforced regulations have led to the understanding that quality control is an essential tool in modern manufacturing and necessary in order to keep production results in deterministic boundaries.Even in the most modern laser based manufacturing systems in operation, few of the key process input parameters are monitored or recorded in any way. The acquisition of such data is usually limited to measuring the laser beam with respect to focal position and power. The online assessment of weld seam quality, both in applications with high penetration depths, as well as those used for the joining of flexible sheets (both metal and non-metals), is a key aspect of maintaining quality. In deep penetration welding of highly stressed components, the consistency of producing defined or full penetration welds is highly desired.Current work in this area is based on the approach of using advanced monitoring strategies. This includes multiple sensing concepts where several independent parameters or features are observed simultaneously in one setup. Besides collecting information directly from the process also geometrical data like shape or size can be used to evaluate the produced quality. Moreover, spatially resolved measurement of temperature radiation yields to additional information. This contribution shows up the current state-of-research and will draw up the route how these lab based results can be used in industrial application in the near future.Laser materials processing is widely used in industry today. The quality of the produced parts is vital for the manufacturer and it is even more important to discover early in the manufacturing process if the required result can be met. ISO 9000 and other by law enforced regulations have led to the understanding that quality control is an essential tool in modern manufacturing and necessary in order to keep production results in deterministic boundaries.Even in the most modern laser based manufacturing systems in operation, few of the key process input parameters are monitored or recorded in any way. The acquisition of such data is usually limited to measuring the laser beam with respect to focal position and power. The online assessment of weld seam quality, both in applications with high penetration depths, as well as those used for the joining of flexible sheets (both metal and non-metals), is a key aspect of maintaining quality. In deep penetration welding of highly stressed components, the consistenc...