Laser hardening of complex geometries with dynamic beam shaping and tempera-ture field control

Seifert Marko - Fraunhofer IWS Dresden (Germany)

In recent years, advancements in laser hardening have increasingly focused on wide-area surface processing for components with complex shapes and larger dimensions. Initial applications are emerging with laser power levels exceeding 20 kW. A key challenge in laser heat treatment lies in producing uniform temperature fields across surfaces that feature curves, edges, boreholes, and varying wall thicknesses. Various strategies are being explored to adapt and optimize the laser beam profile, which significantly influences the resulting temperature distribution.

Dynamic beam shaping with scanning technology has emerged as an effective method for tailoring temperature fields to specific applications. Research has investigated three different approaches to precisely control localized heat input, utilizing computer simulations supported by experimental studies. Here the accurate temperature measurement is crucial for effective temperature field control, typically achieved through camera-based systems and photodiode sensor technology. From the perspective of increasing demands for spatial resolution and rapid response times in modern laser heat treatment applications, the specific characteristics and common measurement errors related to temperature sensing are evaluated through selected case studies.

Looking ahead, the dynamic laser beam shaping with high-speed scanning technology combined with real-time temperature field control presents a promising alternative to conventional solutions in surface heat treatment. This innovative approach could enhance the efficiency and precision of heat treatment processes, especially for components requiring stringent material properties. The ongoing research in this area indicates exciting future prospects for laser hardening, with potential applications across various industries that demand high-performance components.