Study On Microstructure And Properties Of Fe Based Amorphous Power Coating Preparation

By means of laser cladding technology,metallurgical coating can be made on the surface of matrix material, whose dilution rate is very low and can improve the strength, hardness, wear resistance, corrosion resistance and other properties of the matrix surface.In this paper, the Fe-Cr-Si-B-C amorphous composite layers were prepared on pure iron surface using the HGL-6000 crosscurrent CO2 laser. Analysis of the influence of laser processing parameters on microstructure, micro-hardness of the composite coating. By means of optical microscope(OM), X ray diffraction(XRD),scanning electron microscopy(SEM), micro-hardness tester, the microstructure, phase composition, micro area composition, micro hardness are analyzed; and analysis on the coating corrosion resistance and wear resistance by electrochemical workstation and friction wear testing machine.Research shows that the quality of surface coating is good, which has a certain thickness,smooth surface and compact structure.The coating has no amorphous phase,the formation of α-Fe(BCC)and fine Fe2 B phase.With the increase of laser power, dilution rate of the coatings and the shape coefficient increased; the interface between coating and substrate plane at the grain boundary width increases gradually.When the laser power is in the range of2500W-3500 W, with the increase of laser power, the district organization gradually becomes small; when the laser power reaches 4000 W, the district organization becomes coarse; with the laser power increasing, the micro-hardness value reduces.With the increase of scan rate, dilution rate of the coatings and the shape coefficient tends to decline gradually; dendrite size is smaller, so is epitaxial growth layer thickness. The micro-hardness value with the increase of scanning speed increases.When the laser power is 3500 W, scanning speed is 540mm/min, the coating corrosion current average is low to 10-6A/cm2, the corrosion potential is-0.522 V,corrosion resistance performance is good. The highest hardness reaches 796HV0.2, 2.5times than the U75 V rail hardness. Under the same conditions, the loss of cladding layer is the smallest, linear friction factor in 4N are 0.163 and-0.171, respectively0.186 and-0.191 at 8N, the friction process is relatively smooth, wear resistance is good.