Structure and Tribological Performance of Nanostructured ZrO2-3 mol% Y2O3 Coatings Deposited by Air Plasma Spraying

Abstract

In this study, nanostructured ZrO 2 -3 mol% Y 2 O 3 coatings were deposited by air plasma spray using reconstituted feedstock. The coating structures were characterized by x-ray diffractometer, micro-Raman spectrometer, field emission scanning electron microscope, and transmission electron microscope. It is revealed that the as-sprayed coating is mainly composed of columnar grains with diameters <100 nm and demonstrates the better toughness, higher microhardness, and lower porosity. It consists only of nontransformable tetragonal ZrO 2 phase. The tribological performance of the coating was examined with a ball-on-disk apparatus under dry sliding conditions. The results show that the friction coefficient of as-sprayed coating was approximately one-fifth of the conventional zirconia coating and wear rate was lower one order of magnitude than the conventional zirconia coating. The dominant wear mechanism is abrasive wear. The improved wear resistance can be attributed to the increased mechanical properties of as-sprayed coating.

Fracture characteristics of freestanding 8wt% Y2O3–ZrO2 coatings by single edge notched beam and Vickers indentation tests

“…Choi et al [38] showed that H for APS 8 YSZ coatings increases from the as-received value of 2.34-4.49 GPa when the thermal aging time equals about 5 h. Then, it gradually approaches a plateau of 4.36 GPa after annealing 500 h [3]. The results in this paper are in agreement with these data, but they are less than that of nano-structured APS YSZ coatings [40]. Similarly, using the given H, E and Eq.…”

Exploiting Suspension Plasma Spraying to Deposit Wear-Resistant Carbide Coatings

“…Similar findings related to improved wear resistance compared to conventional coatings was reported by Liang et al in the case of nanostructured coatings, and the reason was attributed to their enhanced mechanical properties (higher hardness, higher cohesive strength, higher toughness, etc.) [23]. The above results from our preliminary study with carbide suspensions show considerable promise and clearly motivate further, more detailed, investigations.…”

Effect of TiO 2 addition on the microstructure and nanomechanical properties of Al 2 O 3 Suspension Plasma Sprayed coatings

“…Some example of nanostructured ceramic coatings obtained by APS from agglomerated powders include alumina [16,17], titania [18,19], alumina-titania [14,20], yttria-stabilised zirconia [21,22] or pyrochlore [23].…”