Thermal fatigue resistance of non-smooth cast iron treated by laser cladding with different self-fluxing alloys

In order to enhance the thermal fatigue resistance of gray cast iron with non-smooth surface further, the non-smooth units in samples’ surface layer were fabricated by laser cladding with Fe-based, Ni-based and Co-based self-fluxing alloy powders, respectively, instead of laser melting technique. The microstructure, phase structure, microhardness and thermal fatigue behaviors were investigated by means of scanning electron microscope, X-ray diffraction and Vickers microhardness tester, as well as self-restrain thermal fatigue test. The results indicated that laser cladding with self-fluxing alloy powders was beneficial to reinforcing the units so as to enhance the thermal fatigue resistance of non-smooth samples further. Of all samples tested, those treated by laser cladding with Co-based (Co50) alloy had the best thermal fatigue resistance.