Product Code: ICA10_1901

Parameter Selection in Laser Welding using the Power Factor Concept
Authors:
Wojciech Suder, Cranfield University; Cranfield Great Britain
Stewart Williams, Cranfield University; -
Presented at ICALEO 2010

To achieve specific penetration depths in laser welding particular combinations of laser power and travel speed are required. Different combinations of power and travel speed can be used to obtain the same penetration depth. Further, for a given combination a different penetration depth occurs if a different spot size is used. Spot size is controlled by the laser properties and the optical system, and varies between laser systems. This causes difficulties in both selecting optimum laser parameters for a given application and in transferring parameters between laser systems. This can be greatly simplified using the power factor concept. Power factor is defined as the product of intensity and spot diameter. Plots of constant penetration depth as a function of power factor and interaction time can be generated and these are independent of spot size. Using this concept, system parameters can be selected based on criteria defined by users, such as productivity, process efficiency or heat input. A suitable laser system for that application can then be specified. It also allows transfer of laser parameters between systems. This approach will be illustrated by the use of some specific examples.