Effects of La2O3 on the microstructure and tribological properties of plasma-sprayed Cr2O3–TiO2 coatings

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744033 ◽  
Author(s):  
Qingjun Ding ◽  
Aihua Zhang ◽  
Gai Zhao ◽  
Hanmin Peng ◽  
Wei Gao
Keyword(s):  
Solid Solution ◽  
Surface Roughness ◽  
Tribological Properties ◽  
Adhesive Wear ◽  
Microscopic Analysis ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Properties Of Coatings ◽  
Hardness Tester ◽  
Plasma Sprayed

Cr2O3–TiO2 coatings with different proportions of La2O3 were deposited by atmospheric plasma spraying. The coatings were evaluated by hardness tester, surface roughness tester, SEM and wear tester. The experiment results showed that the addition of La2O3 could improve the microhardness and decrease porosity, wear rate and surface roughness of the coating. The coating containing 2 wt.% La2O3 had the best tribological properties. The dominant wear mechanism is a mixture of abrasive wear and adhesive wear. The microscopic analysis suggests that the addition of La2O3 could refine the microstructure and promote the formation of solid solution powder, and then affect the properties of coatings.

Effects of CeO2 on the microstructure and tribological properties of atmospheric plasma-sprayed Cr2O3-TiO2 coatings

2019 ◽  
Vol 72 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Qingjun Ding ◽  
Gai Zhao
Keyword(s):  
Tribological Properties ◽  
Design Methodology ◽  
Solution Structure ◽  
Adhesive Wear ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Content Type ◽  
Plasma Sprayed

Purpose The purpose of this paper is to study the mechanism and effect of rare earth oxides on the properties of Cr2O3-TiO2 coating. Design/methodology/approach Cr2O3-TiO2 coatings with different proportion of CeO2 were deposited by atmospheric plasma spraying on aluminum alloy 7005. The mechanical, microstructure and tribological properties were studied. Findings The addition of CeO2 could improve the micro-hardness; decrease porosity, wear rate and surface roughness of the coating; and increase the bonding strength between the coating and substrate. The wear mechanism is a mixture of abrasive and adhesive wear. Originality/value The addition of CeO2 could refine microstructure, and promote the formation of solid solution structure, and then affect the properties of coatings.

Microstructure of Atmospheric Plasma Sprayed (Al,Cr)2O3-TiO2 Coatings from Blends

2021 ◽  
Author(s):  
Maximilian Grimm ◽  
Rico Drehmann ◽  
Thomas Lampke ◽  
Susan Conze ◽  
Lutz-Michael Berger
Keyword(s):  
Solid Solution ◽  
Plasma Spraying ◽  
Chromium Content ◽  
Defect Density ◽  
Deposition Efficiency ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Tio2 Content ◽  
Tio2 Coatings ◽  
Plasma Sprayed

Abstract This study investigates the microstructure and hardness of coatings produced by atmospheric plasma spraying using a commercial (Al,Cr)2O3 solid solution (ss) powder blended with various amounts of TiO2. The microstructures were analyzed using SEM, EDS, and XRD measurements. It was shown that blending with TiO2 reduces porosity and defect density while increasing deposition efficiency and microhardness. Small amounts of Ti in ss (Al,Cr)2O3 splats were detected in coatings prepared from blends with higher TiO2 content. Variations in aluminum and chromium content were also observed.

Constrained and Non-Constrained Sintering of Plasma-Sprayed Zirconia Based Electrolytes for SOFCs

2010 ◽  
Vol 65 ◽  
pp. 263-268 ◽  
Author(s):  
Claudia Christenn ◽  
Syed Asif Ansar
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Atmospheric Plasma Spraying ◽  
Solid Oxide ◽  
Yttria Stabilized Zirconia ◽  
Atmospheric Plasma ◽  
Oxide Fuel ◽  
Microstructure Development ◽  
Stabilized Zirconia ◽  
Free Standing ◽  
Plasma Sprayed

Electrolyte layers for solid oxide fuel cells (SOFCs) consisting typically of yttria-stabilized zirconia were prepared using atmospheric plasma spraying in a first step and sintered in a second one. The influence of particle size on sintering kinetics and microstructure development was analyzed by comparison of nanostructured and conventional YSZ layers. Sintering of free-standing coatings differ significantly from that of coatings on substrates.

Plasma Sprayed Alumina Coating on Ti6Al4V Alloy for Orthopaedic Implants: Microstructure and Phase Analysis

2012 ◽  
Vol 510-511 ◽  
pp. 547-553 ◽  
Author(s):  
M. Khalid ◽  
M. Mujahid ◽  
Aamer Nusair Khan ◽  
R.S. Rawat ◽  
I. Salam ◽  
...  
Keyword(s):  
Phase Analysis ◽  
Atmospheric Plasma Spraying ◽  
Ti6al4v Alloy ◽  
Atmospheric Plasma ◽  
Alumina Coating ◽  
Splat Morphology ◽  
Cross Sectional ◽  
Arc Current ◽  
Plasma Sprayed ◽  
Sectional Analysis

Alumina was coated on Ti6Al4V alloy by atmospheric plasma spraying. Surface and cross sectional analysis of the coating by SEM showed that diameter and thickness of splat was greatly influenced by arc current and stand-off distance. In turn, this variation in splat morphology had effect on evolution of α-Al2O3 and γ-Al2O3 phases as revealed by XRD. Higher proportion of required γ-Al2O3 phase was achieved at stand-off distance of 130 mm and arc current of 500A.

scholarly journals Effect of Cold Atmospheric Pressure Plasma Coupled with Resin-Containing and Xylitol-Containing Fluoride Varnishes on Enamel Erosion

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Zahra Khoubrouypak ◽  
Mahdi Abbasi ◽  
Elham Ahmadi ◽  
Niyousha Rafeie ◽  
Marjan Behroozibakhsh
Keyword(s):  
Surface Roughness ◽  
Artificial Saliva ◽  
Atmospheric Pressure Plasma ◽  
Atmospheric Plasma ◽  
Fluoride Varnish ◽  
Lower Percentage ◽  
Control Group ◽  
Hardness Tester ◽  
Significant Difference ◽  
Enamel Erosion

Purpose. Considering the suggested advantages of cold atmospheric plasma (CAP) in increasing the fluoride uptake by the enamel, this study aimed to assess enamel erosion following the application of helium CAP and two types of fluoride varnishes. Methods. The microhardness of 70 bovine enamel specimens was measured using a Vickers hardness tester. The specimens were randomly divided into 7 groups (n = 10): control, CAP (P), resin-containing fluoride varnish (RF), CAP + resin-containing fluoride varnish (PRF), fluoride varnish (F), CAP + fluoride varnish (PF), and erosion (E). The specimens in the control and erosion groups did not receive CAP or fluoride varnish. All specimens underwent erosive challenge 4 times/day using hydrochloric acid and artificial saliva except for the control specimens that remained in distilled water during the course of the study. After 5 days of erosive challenge, microhardness was measured again, and the percentage of microhardness change was calculated. Surface roughness of two specimens in each group was assessed by atomic force microscopy (AFM). Data were analyzed using one-way ANOVA followed by Tamhane’s post-hoc test. Results. The percentage of microhardness change in all groups was significantly higher than that of the control group. All groups showed significantly lower percentage of microhardness change compared with the E group except for the P group; no significant difference was noted in microhardness change of P and E groups. Other experimental groups had no significant difference with each other. Surface roughness was the highest in PRF and the lowest in the F group. Conclusion. CAP application had no significant effect on increasing the enamel resistance to erosion. However, enamel resistance to erosion increased significantly after fluoride varnish application alone or fluoride varnish application combined with CAP. No significant difference was noted between the two types of varnishes in this regard. CAP increased the surface roughness while fluoride varnish application alone decreased the roughness.

Tribological properties of adaptive NiCrAlY–Ag–Mo coatings prepared by atmospheric plasma spraying

2013 ◽  
Vol 235 ◽  
pp. 521-528 ◽  
Author(s):  
Jie Chen ◽  
Yulong An ◽  
Jie Yang ◽  
Xiaoqin Zhao ◽  
Fengyuan Yan ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Tribological Properties ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma

Tribological Properties of Plasma-Sprayed 20 wt. % ZrO2-Al2O3-17 wt.% TiO2 Coatings on Plain Carbon Steel Substrate

2012 ◽  
Vol 463-464 ◽  
pp. 420-424
Author(s):  
San Ming Du ◽  
Yong Ping Niu ◽  
Yong Zhen Zhang
Keyword(s):  
Carbon Steel ◽  
Tribological Properties ◽  
Steel Substrate ◽  
Plain Carbon Steel ◽  
X Ray Diffraction ◽  
Properties Of Coatings ◽  
Bond Layer ◽  
Spray Technique ◽  
Pin On Disc ◽  
Plasma Sprayed

In the present study, 20 Wt. % ZrO2-Al2O3-17 wt.% TiO2 powders were sprayed using a plasma-spray technique after a NiAl bond layer was deposited on plain carbon steel substrate. The produced coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) including energy-dispersive spectroscopy (EDS). The tribological properties of coatings against hard alloy ball were investigated by using a pin-on-disc tribo-meter under dry environments. The predominant wear mechanism of coating is fatigue.

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