A study of the laser cladding of powder metallurgical tool steels has been carried out. CPM 10 V and Vanadis 4 Extra tool steel powders have been deposited on Vanadis 4 Extra tool steel plates, for repairing purposes, using a Nd:YAG laser. The microstructure of the laser cladding samples was investigated using optical and scanning electron microscopes. The volumetric fraction of retained austenite was evaluated by X-ray diffraction and microhardness profiles were measured. Crack free 700 HV 0.3 cladding tracks were achieved with both materials and coatings show a microstructure of carbides embedded in a martensite plus retained austenite matrix.

The metal was locally structured by pulsed laser radiation producing microscopic patterns on its surface. In a second step the opposite side of the micro-structured metal was irradiated by a continuous wave (CW) fiber laser to achieve the mechanical interlock between the two materials. A tight relationship between the microstructure parameters and pull-out test performance was observed. The greatest strength was achieved when the distance between subsequent grooves was minimized. The T-joint mechanical performance did not reveal any significant dependence on the considered range of joining areas. The morphological and topographical features of the detached surfaces showed that the micro-structured grooves were completely filled during the laser conductive joining process. Different alignment angles of patterns produced different failure modes although there was no evidence of an additional mechanical interlock

A two-step method for the joining of opaque polymer to metal is presented. Firstly, the metal is structured locally on a micro-scale level, to ensure adhesion with the polymeric counterpart. In a second step, the opposite side of the micro-structured metal is irradiated by means of a laser source. The heat thereby created is conducted by the metal and results in the melting of the polymer at the interface. The polymer thereby adheres to the metal and flows into the previously engraved structures, creating an additional mechanical interlock between the two materials. The welding parameters are fine-tuned with the assistance of a finite element model, to ensure the required interface temperature. The method is illustrated using a dual phase steel joined to a fiber-reinforced polyamide. The effect of different microstructures, in particular geometry and cavity aspect ratio, on the joint's tensile-shear mechanical performance is discussed