The Fabrication And Property Analysis Of Fe-Based Amorphous Composite Coatings With The Different Content Of Molybdenum

To investigate the effect of Mo element on Fe-based amorphous/nano-crystalline composite coating,10 composite coatings were prepared by the pulse laser cladding method.The coatings were analyzed by means of XRD,SEM and EDS.The mechanism and law of the effect of Mo on the amorphous phase and nano-crystalline in Fe-Mo-Cr-Y-B-C alloy were studied.The hardness enhancement mechanism,corrosion behavior and corrosion resistance mechanism of the composite coatings were studied in this paper.While,the results showed that all of the coatings are composed of amorphous phase and nano-crystalline.The main nano-crystalline were(Fe,Cr)7C3,(FexCy),Mo2C and Fe9.7Mo0.3 According to full width at half maximum(FWHM)of diffraction patterns,the content of amorphous phase decreased first and then increased with the increase of the content of Mo element,which illustrates that molybdenum is good for improving the glass forming ability(GFA).From the SEM results,it can be found that there are amounts of grains and second phases enriched in the middle of the coatings which distribute like belt form.And the band width is narrower and the grain size becomes larger with the increase of Mo content.The microhardness tests showed that all the coatings have higher microhardness in the range of 871HV0.3?1298HV0.3,which are 4-5 times harder than that of the substrate.Due to the amorphous/nanocrystal composite structure,the hardness of the coatings are improved.Electrochemical test indicated that all the coatings have better corrosion resistance than that of the substrate.The corrosion current density decreases with the increase of Mo content and the corrosion current density of 0%Mo coating is 20 times higher than that of 2%Mo coating,which suggests that the addition of Mo could improve the corrosion resistance of the coatings.The details were discussed in the paper.