D02 - Laser-Hardness
D02 - High-speed hardness measurements of metallic materials
Conventional testing methods are based on time- and resource-intensive investigations of a wide range of material properties. A frequently used test method is the hardness measurement. Hardness test methods can be used to determine the indentation resistance of a material. Standardized test specimens are pushed into the material under a defined force. Subsequently, the resulting indentation area or depth is measured. In order to meet the requirements of an efficient identification of new materials and compositions, a novel high-speed hardness testing method based on laser-induced shock waves is investigated within the SFB 1232 "Farbige Zustände" in the subproject "Laser Hardness". This method is to enable a hardness measurement consisting of test, measurement and evaluation time of less than one second.
In contrast to conventional measuring methods, a TEA CO2 laser is used to generate a shock wave (see Figure 1) above a test specimen, causing it to be pushed into a material surface by impulse transfer (see Figure 2). The propagation of the shock wave can be made visible by the Schlieren method.
Laser systems offer the possibility to achieve high-throughput in the micro range because they are highly dynamic and flexible. The central question of the sub-project is therefore to gain a profound understanding of laser shock processes in order to make them usable as measuring methods.