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

摘要

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 nonsmooth samples further. Of all samples tested, those treated by laser cladding with Co-based (Co50) alloy had the best thermal fatigue resistance.