The primary objective of this thesis is to investigate the feasibility of the welding process for steel withHardmetal (WC-Co) by using laser energy, mainly for new geometries by increasing the currentthickness. Additionally, the viability of modifying the hardmetals grade and steel composition isincluded. This study is part of a long-term objective of CERATIZIT to expand the market of laser weldedtools, and to embrace an extended catalogue of steel-hardmetal geometries.

This project was conducted at CERATIZIT S.a.r.l facilities in Mamer, Luxembourg from February 2018to August 2018. Three different geometries were selected to produce laser welded samples. Astatistical approach to find out the optimal parameters for each geometry is made. Shear strengthtests of the produced samples were carried out to establish a numerical quality result, and to comparethese with previous studies. The analysis of the resulting weld seam shape is used to find correlationsbetween the appearance and the mechanical properties. Moreover, the fracture of the mechanicallytested samples is classified to understand the failure mechanism of the different geometries and theexisting defects on the joined zone.

A microstructural investigation of the weld seam and the interface between the steel and thehardmetal is performed, by using optical microscopy, SEM and Energy dispersive X-Ray Spectroscopy(EDS) analysis for the chemical composition. The general similarities and differences on themicrostructure depending on the geometry or the production parameters are explained and linked tothe quality standards searched for a future production