| As the existence of the room temperature brittleness and the difficulty of forming defects, thepractical application of Fe-Al intermetallic compounds has been hampered. Although the wholeforming process such as powder metallurgy and casting can reduce or avoid the problem of forming, itwill bring problems of another processing technologies and additional decline in the performance ofmaterials. So we proposed the method that combined multi-element alloying with the surfacetechnology, adding elements of Cr and Nb in the Fe-Al alloy, and preparing Fe-Al-Cr-Nb alloy layeron the surface of45steel by double glow plasma surface technology. So the properties of Fe-Al alloycan be effectively improved and at the same time, we also solve disadvantages of the difficult tomachining.This paper is based on the optimal technological parameters of preparation of Fe-Al-Cr-Nb alloylayer.The alloy layer’s morphology, microstructure and phase composition were studied by scanningelectron microscopy, energy dispersive spectroscopy and X ray diffraction. And then the hardness,bonding force, elastic modulus, wear and corrosion properties of the alloy layer were tested andanalyzed.The results show that, Fe-Al-Cr-Nb alloy layer was made on the optimal process parameters, andthe thickness of layer is about10μm, alloy layer is uniform and compact, and has a good combinationwith matrix; The surface of alloy layer is granular, Fe-Al-Cr-Nb alloy layer is mainly composed of Cr,Fe2Nb and NbC; Dynamic micro hardness and elastic modulus of alloy layer is10.18GPa and498.7GPa, and they are far higher than that of the matrix, it shows the alloy layer has a strong antideformation capability; Wear tests show that the alloy layer’s capability of wear resistance hasimproved about6~10times than the matrix which means Fe-Al-Cr-Nb alloy layer is beneficial tomatrix; Electrochemical tests show that in3.5%NaCl solution and5%H2SO4solution, the currentcorrosion density of Fe-Al-Cr-Nb alloy layer is far less than that of45steel substrate; In theimmersion tests, the corrosion rate of alloy layer has reduced by6.1times than the matrix, this showsthat compared with the matrix, the corrosion resistance of Fe-Al-Cr-Nb alloy layer increasedevidently. |
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