Pulsed laser synthesis of ceramic–metal composite coating on steel

A pulsed Nd:YAG laser was employed to modify the surface properties of AISI 1010 steel with precursor of TiB2 + Al. A set of samples were prepared with different laser processing parameters and compositions of the precursor in order to study the effect of Al on the coating. Thermal modeling was performed to quantitatively evaluate the maximum temperature and the range of cooling rate for the melting pool. Phase constituents and microstructure were characterized using X-ray diffractometer, optical microscopy, and scanning electron microscopy. Results show that TiB2 dissociated when the Al content reached 30 wt.% or more. The composite coating with the presence of TiB2 shows acicular TiB2 particles embedded in the α-Fe matrix. Coatings produced using precursor of high-Al content reveals a refined cellular structure due to the high-cooling rate induced by short pulse duration. Compared with the steel substrate, microhardness and wear resistance of the coating are improved significantly.