Investigation Of Plasma Sprayed Mo/Cr₃C₂-30NiCr Coating On Mould CuCrZr Alloy Plates

The Mo coating and Mo/Cr3C2-30NiCr coating were prepared by plasmaspraying on the CuCrZr alloy for mould. Firstly, the plasma spraying processingparameters were optimized by the Uniform Test with the bonding strength. And then,using Spray Watch-2i system measured the parameters which prepared with theoptimized parameters was done to investigate the thermal shock resistance of thecoatings. The hardness of the Mo/Cr3C2-30NiCr coating were tested to analyze theirdistribution. And also microstructure and fracture of the plasma sprayed coating wereinvestigated by means of SEM, EDS, XRD and so on. Study the high-temperaturefriction and wear properties of composite coatings. So, the effects of four parameters,including spraying distance, primary gas flow rate, deliver powder rate and spraypower, on the plasma sprayed Mo coating and Mo/Cr3C2-30NiCr coating were studied.Within the processing parameters of this experiment, the results are as follows.For Mo coating Using MATLAB for uniform test data processing quadraticpolynomial regression, obtained quadratic regression equation：Y=328.8+7.4X2222+0.005X1+0.18X3+0.01X4According to their correlation coefficient, the effect of these parameters on thebondingstrength of Mo coating is as follows: X3>X2>X4>X1.Mo coating is sprayed adopting optimized process parameters, the bondingstrength is obtained to be61.5MPa, porosity of0.31%. Coating properties has beenenhanced obviously after optimization. performance of all aspects than before have amore substantial increase.For Mo/Cr3C2-30NiCr coating Using MATLAB for uniform test data processingquadratic polynomial regression, obtained quadratic regression equation：Y=29.79251.2991X2.1406X+3.8324X+0.010325X20.01697X212414According to their correlation coefficient, the effect of these parameters on thebondingstrength of Mo coating is as follows: X4>X1>X2>X3.Mo/Cr3C2-30NiCr coating is sprayed adopting optimized process parameters,the bonding strength is obtained to be60MPa, porosity of0.26%. Coating propertieshas been enhanced obviously after optimization. performance of all aspects thanbefore have a more substantial increase.Mo coating and Mo/Cr3C2-30NiCr coating have good thermal shock resistance and high thermal fatigue life which reaches higher number of macro-crack initiationand failure times. When Mo coating thickness from0.2mm increasing thermal shockresistance of the coating is increasing,0.4mm thermal shock resistance of the best,when the thickness of more than0.4mm thermal shock resistance of the coatingdecreased rapidly over0.6mm thickness thermal shock resistance is still declining, butslowed down. As the temperature increases, the thermal shock to continuously reducethe life of the coating. A primer layer and substrate occurs at oxidized to form theoxide coating failure are accelerated, reducing the life of the coating thermal shock.Cr3C2-30NiCr coating hardness in the direction parallel to the substrate,significantly normal distribution.Tribological properties of the coating Mo/Cr3C2-30NiCr at different loads anddifferent temperatures is:Mo/Cr3C2-30NiCr friction coefficient of the coating underthe same load, both decreases with increasing temperature;Mo/Cr3C2-30NiCrcoefficient of friction coating increases the load increases;...