The Preparation Of Tantalum Coating And The Research Of Wear And Ablation Resistance

Tantalum (Ta) coating was electroplated from Fluoride for better coating of the PCrNisMo steel with orthonal test. And for the better combination of the Ta coating, the method of double glow plasma tantalizing on the PCrNi3Mo steel is used. The composition, microstructure, morphologies of the D-Ta coating (electroplating in molten salt) and S-Ta coating(double glow plasma tantalizing) were analyzed by scanning electron microscopy (SEM), energy diffraction spectrum (EDS), X-ray diffraction (XRD) and micro hardness tester.In contrast with Cr coating and substrate, the wear resistance, laser ablation resistance and corrosion properties of D-Ta coatings and S-Ta composite coating on substrate surface were analyzed by high temperature friction wear tester (HT1000), laser pulse (YAG-M50) and potentiodynamic polarization respectively. The results show that:1. The optimal process parameters for the electroplating of Ta coating is 750℃,3h, 80ma/cm2, Ra=0.05μm. In this condition the hardness of Ta coating is higher to 950HV0.2 and the anneal making it soft. The S-Ta coating which used the method of double glow plasma tantalizing show:a Ta with preferred [211] orientation and better surface finishment.2. In the room temperature the friction coefficient of substrate, Cr coating, D-Ta coating and S-Ta coating is respectively 0.89,0.78,0.58,0.60 and the wear rate is 5.47×10-4、2.98×10-4、2.65×10-4、2.45×10－4 mm3/N·m. Wear performance is not improved obviously. In the higher temperature, the friction coefficient of substrate, Cr coating, D-Ta coating and S-Ta coating is respectively 0.72、0.65、0.42、0.31 and the value of wear rate become none of meaning because of weight gain of oxidation under the high temperature. But, the depth of wear scar of S-Ta coating is the minimum. The wear resistance is increased obviously and the formation of tantalum oxide is the key factor.3. The laser pulse analysis indicated that the ablation resistance arrangement is S-Ta coating, D-Ta coating, Cr coating and substrate. The formation of tantalizing coating with good interlayer situation make it has better performance than D-Ta coating.4. At the same time, The surface activity is reduced, the corrosion potential of substrate, Cr coating, D-Ta coating and S-Ta coating is respectively-1006,-910,-545mv and-429mv. S-Ta coating significantly enhances the corrosion properties.