Comparative Investigation on Wear Properties of Composite Coatings with Varying CeO2 Contents

Abstract

Several innovative mixed powders of Ti6Al4V and NiCr-Cr3C2 with different CeO2 contents (0, 1, 2, 3, and 4 wt.%) were designed, and Ti2C-reinforced CrTi4-based composite coatings were prepared on the Ti6Al4V surface via laser cladding technology. The effects of CeO2 amount on the forming quality, microstructure, hardness, and wear resistance of the composite coatings were studied. The results showed that the CeO2 amount had a significant influence on the forming quality of the composite coatings. The cracks were eliminated completely when the CeO2 content was 2 wt.%; furthermore, the lowest porosity was obtained with the addition of 3 wt.% CeO2. The primary phase constituents of the coatings were non-stoichiometric Ti2C and a β-type solid solution (CrTi4) as the reinforcement and matrix, respectively. CeO2 and a low quantity of Ce2O3 were re-precipitated at the Ti2C/CrTi4 interface and CrTi4 grain boundary in the coatings with CeO2 addition. In addition, the average hardness of the composite coatings was 1.28–1.34 times higher than that of the Ti6Al4V substrate. The wear resistance of the composite coatings was significantly higher than that of the substrate. However, both the composite coatings and the Ti6Al4V substrate exhibited a mixed-wear mode, i.e., abrasive and adhesive wear.

Effects of Nano-CeO2 on Microstructure and Properties of WC/FeCoNiCrMo0.2 Composite High Entropy Alloy Coatings by Laser Cladding

“…Energy spectroscopy and scanning elemental distribution of two coatings, namely, HEA/WC and HEA/WC + CeO 2 , were performed using an energy dispersive spectrometer (EDS). Figure 6 and Figure 7 show the results of energy spectrum analysis [ 13 ] and their elemental distribution for the surface sweep of the top part of the HEA/WC and HEA/WC + CeO 2 coatings, respectively [ 18 , 21 , 40 ].…”

“…Figure 9 a,b show the friction coefficient curves of three kinds of coatings and substrate with the change of wear time and the wear weight loss of samples [ 13 , 21 ] before and after the test. This shows that there were two phases of initial running-in and stable break-in for all three coatings.…”

“…Research shows that the addition of 4.0% CeO 2 can effectively suppress cracks and porosity in the Ni60 clad layer, promote grain refinement, and improve tissue uniformity, but too much CeO 2 will cause lattice distortion in each phase of the coating. Zhang et al [ 21 ] added CeO 2 powder to Ti6Al4V + NiCr-Cr 3 C 2 composite powder to study the effect of CeO 2 on the forming quality and microstructure of a TiC x -reinforced CrTi 4 -based composite coating by laser cladding technology. The results showed that the content of TiC x dendrites is closely related to the CeO 2 content.…”

Effect of CeO2 Content on Microstructure and Wear Resistance of Laser-Cladded Ni-Based Composite Coating

“…The reason for the higher hardness of the S1 and S2 samples is that the addition of a low content of CeO2 makes the microstructure of the cladding layer denser and the grains gradually smaller [21]. The grain refinement and solid solution strengthening effect improve the strength and microhardness of the cladding layer [26]. Furthermore, the heightened surface hardness observed in sample S3 can be attributed to two primary factors: Firstly, Figure 3(a4) reveals a higher presence of unmelted WC particles in the middle and lower sections of the coating, contributing to enhanced coating hardness [16,17].…”

Effect of Y2O3 Content on Microstructure and Corrosion Properties of Laser Cladding Ni-Based/WC Composite Coated on 316L Substrate

“…The dendritic carbide evenly distributed in the cladding coating promotes the transfer of load to the tough substrate phase and releases stress through coordinated deformation, thus avoiding brittle fracture of the carbide. In addition, grain refinement and the solid-solution-strengthening effect enhance the strength and microhardness of the cladding coating, thus improving the wear resistance property of the cladding coating [42]. Under a long time of wear, the carbide-reinforcing phase will come off gradually, thus resulting in degradation of the wear resistance and an increase in the frictional coefficient.…”