Effect of CeO₂ on crack sensitivity and tribological properties of Ni60A coatings prepared by laser cladding

Abstract

All the time, the wear resistance of TC4 titanium alloy restricts its application in friction parts. In order to solve this problem, in this work, CeO2/Ni60A composite coatings (0, 1, 2, 3, 4 wt.% CeO2) were prepared on TC4 titanium alloy by laser cladding technology. The detection and characterization of the coatings were mainly carried out by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy-dispersive spectrometer, Vickers hardness test, and wear test. The results showed that appropriate proportion of CeO2 powder could effectively reduce the crack sensitivity of Ni60A coating on TC4 substrate. While the amount of CeO2 powder was 3wt.%, there were no obvious cracks, pores, and other defects in the coating. Coatings mainly consisted of Ti2Ni, TiC, TiB2, Ce2O3, and the substrate α–Ti. CeO2 has negligible influence on the composition of the phase, but it significantly increased the absorption rate of the powder to light, promoted the fluidity of the molten pool. Among five coatings, the average hardness of the 3Ce coating was the highest and the highest hardness value could reach 1163.7 HV0.3, which was 3.58 times higher than TC4 substrate, the friction coefficient was 0.307, and the wear rate was 1.11 × 10−5 mm3/N m, which reflected extremely high wear resistance performance. Adding an appropriate amount of CeO2 improved the microstructure of the coating, and realized the fine crystal strengthening of the coating.

Microstructure and Wear Resistance of Ti6Al4V Titanium Alloy Laser-Clad Ni60/WC Composite Coating

“…The study of chemical reactions in the melt pool is of great significance, as it helps with the accurate prediction of possible reactions in the melt pool and facilitates controlling the organization and relevant properties of the coating. During laser melting, the matrix Ti6Al4V and Ni60/WC powders undergo complex physicochemical reactions to form different phase compositions during the melt pool reaction [ 25 ]. Firstly, under the intense energy of the laser beam, Ni60 powder undergoes dissolution, and WC particles experience partial dissolution.…”

Research Progress of Laser Cladding on the Surface of Titanium and Its Alloys

“…Such an improvement was mainly ascribed to the higher supercooling resulting from the existence of Y 2 O 3 and the wear properties are benefited by the microstructure evolution. Gong et al [182] added CeO 2 in a Ni60A powder to prepare the cladding layer on the TC4 alloy substrate and found that the added CeO 2 promoted the absorption of energy and increased the fluidity of the molten pool. The improvement of melt reduced the crack sensitivity of the cladding layer and increased the hardness and wear resistance.…”

Unique Yttria Nanoparticle Strengthening in an Inconel 718 Superalloy Fabricated by Additive Manufacturing

“…To this end, AM is showing its potential to revolutionize the production of ODS superalloys, e.g., Al 2 O 3 and HfO 2 doped Fe-Cr-based superalloys fabricated by laser melt deposition (LMD), [18,19] CeO 2 modified Ni-Cr-based superalloys fabricated by directed laser deposition (DLD). [20] Particularly, laser powder bed fusion (LPBF), a widely used AM technique, has recently been employed in trials to produce Y 2 O 3 strengthened alloys in Inconel 625, [21] 𝛾/𝛾′ Ni-based superalloys [22][23][24] and IN718. [25][26][27][28] So far, the reported effects of Y 2 O 3 particles on strengthening were variable in these alloys.…”