Prepared SiCp/Cu Functionally Gradient Materials By Laser Cladding

SiCp/Cu FGM is a new type of functional materials, it not only has excellent properties ofthe matrix of copper and has excellent performance SiCpreinforcement, and have broadapplication prospects in aerospace, electric locomotives and other fields.In this paper, prepared SiCpcomposite powder coated with copper by chemical platingmethod for surface treatment of SiCp, used scanning electron microscope (SEM) and energydispersive spectroscopy (EDS) to study effect of the reductant content, the temperature ofbath, the pH of bath, the reaction time and the content of complexing agent to the coating.Used the mixed powder of SiCpcomposite powder coated with copper and663bronzepowder as the raw material, to prepared the SiCp/Cu FGM coating by laser cladding, and usedthe spectrum analyzer(EDS) and the X-ray diffraction meter(XRD) gradient composites to dothe phase analysis, and used the versatile surface properties tester and wear tester tocharacterize the hardness, the friction and wear properties of the coating. Draw the followingconclusions is that:(1) With the content of the reductant content is increasing, the temperature is higher, thepH value is increasing, the reaction time is longer and the complexing agent content isincreasing, the effect of plating becomes better, and other components of the plating bath haslittle impact for the plating results. When the reaction time Plating of is40min, the bathtemperature of plating is50?, the pH plating bath is12and the formulation of the chemicalbath of preparation of such composite particles is: CuSO4·5H2O:30g/L, EDTA·2Na:1g/L,K4[Fe(CN)6]·3H2O:2g/L, NaOH:34g/L, CH2O:24ml/L, KNaC4H4O6·4H2O:105g/L, at thispoint the effect of Chemical plating is best, and it is the optimal parameters of electrolesscopper.(2) The parameters to prepare the gradient layers of3layers and the gradient distributionof5vol.%,10vol.%,15vol.%Of SiCp/Cu FGM coating by laser cladding is: the laser spotdiameter is1mm, the powder feeder feed rate is7.5g/min, the laser power is500-800W andlaser scanning rate is6-12mm/s. As the laser power increasing, the effect of coating is gettingbetter, but when it is more than some power the porosity of the surface of coating is increasing,and the effect of cladding is variation; with the increase of the scan rate of the laser, thicknessof the coating becomes increasingly smaller, the thickness becomes too large and theutilization of the powder become too low when the scan rate is too low, and the impact of thecoating becomes thin and the continuity of the coating becomes worse when scanning speed istoo large. The cladding of the SiCp/Cu FGM coating is best when the laser power is700W, laser scanning rate is8mm/s.(3) The microhardness of the10vol.%SiCp/Cu composite cladding coating is up to112HV, its friction coefficient is up to0.392, its minimum amount of wear is10.2‰;microhardness of the SiCp/Cu FGM coating Cladding is up to138HV, its minimum amount ofwear is9.7‰; the microhardness properties and wear resistance of SiCp/Cu FGM coatingcoating is better than10vol.%SiCp/Cu composite coating that Laser Cladding prepared.