The laser alloying process of ductile cast iron surface with titanium

The article presents the results of the laser alloying process of ductile cast iron EN-GJS 350-22 surface with titanium. The laser alloying process was conducted on 2 kW high power diode laser (HPDDL) Rofin Sinar DL02 with rectangular focus and uniform power density distribution in the focus axis. The laser alloying was conducted with constant laser beam power and processing speed with titanium powder feed rate variation. The tests of the produced surface layers included macrostructure and microstructure observations, X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analysis, Vickers hardness, and solid particle erosion according to ASTM G76-04 standard. To assess the erosion mechanism, SEM observations of worn surfaces after erosive test were carried out. As a result of laser alloying of a ductile cast iron surface, the in situ metal-matrix composite structure was formed with TiC reinforcing particles. The microstructure change resulted in the increase of surface layers hardness and erosion resistance in comparison to the base material.