scholarly journals Microstructure and Wear Behaviors of Plasma-Sprayed MoAlB Ceramic Coating

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 474
Author(s):  
Fuzhu Li ◽  
Shengnan Sun ◽  
Yong Xu ◽  
Lihui Tian ◽  
Yun Wang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Plasma Spraying ◽  
Ceramic Coating ◽  
Adhesive Wear ◽  
Ceramic Coatings ◽  
Atmospheric Plasma ◽  
Wear Rates ◽  
Arc Power ◽  
Plasma Sprayed

MoAlB ceramic coatings were prepared on a 316 steel surface by atmospheric plasma spraying with different arc power levels. The phase composition, microstructure and wear resistance of coatings against GCr15 and Si3N4 counterparts were studied. The MoAlB ceramic decomposed and was oxidized to form MoB and Al2O3 during plasma spraying. With the increase of the arc power, MoAlB experienced more decomposition, but the coatings became denser. When the arc power increased from 30 to 36 kW, the wear rates of coatings against GCr15 and Si3N4 balls reduced by 91% and 78%, respectively. The characterization of wear tracks shows that when against GCr15 counterparts, the main wear mechanisms are abrasive and adhesive wear, and when against Si3N4 counterparts, fatigue and abrasive wear are dominant. The refinement of wear resistance by increasing arc power can be attributed to the improvement of density and adhesive strength among splats.

scholarly journals Wear Behavior Analysis of Al2O3 Coatings Manufactured by APS and HVOF Spraying Processes Using Powder and Suspension Feedstocks

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 879
Author(s):  
Monika Michalak ◽  
Paweł Sokołowski ◽  
Mirosław Szala ◽  
Mariusz Walczak ◽  
Leszek Łatka ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Wear Behavior ◽  
Ceramic Coatings ◽  
Suspension Plasma Spraying ◽  
Atmospheric Plasma ◽  
Hvof Spraying ◽  
The Coefficient Of Friction ◽  
Wear Mode ◽  
Α Al2o3 ◽  
Plasma Sprayed

Thermally sprayed ceramic coatings are applied for the protection of surfaces that are exposed mainly to wear, high temperatures, and corrosion. In recent years, great interest has been garnered by spray processes with submicrometric and nanometric feedstock materials, due to the refinement of the structure and improved coating properties. This paper compares the microstructure and tribological properties of alumina coatings sprayed using conventional atmospheric plasma spraying (APS), and various methods that use finely grained suspension feedstocks, namely, suspension plasma spraying (SPS) and suspension high-velocity oxy-fuel spraying (S-HVOF). Furthermore, the suspension plasma-sprayed Al2O3 coatings have been deposited with radial (SPS) and axial (A-SPS) feedstock injection. The results showed that all suspension-based coatings demonstrated much better wear resistance than the powder-sprayed ones. S-HVOF and axial suspension plasma spraying (A-SPS) allowed for the deposition of the most dense and homogeneous coatings. Dense-structured coatings with low porosity (4 vol.%) and good cohesion to the metallic substrate, containing a high content of α–Al2O3 phase (56 vol.%) and a very low wear rate (0.2 ± 0.04 mm3 × 10−6/(N∙m)), were produced with the S-HVOF method. The wear mechanism of ceramic coatings included the adhesive wear mode supported by the fatigue-induced material delamination. Moreover, the presence of wear debris and tribofilm was confirmed. Finally, the coefficient of friction for the coatings was in the range between 0.44 and 0.68, with the highest values being recorded for APS sprayed coatings.

Laser Sintering of Nano-Al2O3 Powders on Plasma Sprayed Ceramic Based Coatings

2007 ◽  
Author(s):  
Lida Shen ◽  
Yinhui Huang ◽  
Zongjun Tian ◽  
Guoran Hua
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Plasma Spraying ◽  
Bond Coat ◽  
Continuous Wave ◽  
Ceramic Coatings ◽  
Laser Sintering ◽  
Al2o3 Ceramic ◽  
Plasma Sprayed ◽  
Steel Substrates

This paper describes an investigation of nano-Al2O3 powders reinforced ceramic coatings, which has included NiCrAl and Al2O3+13%wt.TiO2 coats pre-produced by atmosphere plasma spraying, implemented by laser sintering. Commercial NiCrAl powders were plasma sprayed onto 45 Steel substrates to give a bond coat with thickness of ∼100μm. The 600μm thick Al2O3+13%wt.TiO2 based coating was also plasma sprayed on top of the NiCrAl bond coat. With 2.5kw continuous wave CO2 laser, nano-Al2O3 ceramic powders were laser sintered on the based Coatings. The micro structure and chemical composition of the modified Al2O3+13%wt.TiO2 coatings were analyzed by such detection devices as scanning electronic microscope (SEM) and x-ray diffraction (XRD). Microhardness, wear resistance and corrosion resistance of the modified coatings were also tested and compared with that of the unmodified. The results show that the crystal grain size of Al2O3 had no obvious growth. In addition, due to the nanostructured Al2O3 ceramic phases, the coatings exhibited higher microhardness, better wear resistance and corrosion resistance than those unmodified counterparts. The complex process of plasma spraying with laser sintering as a potential effective way of the application of ceramic nano materials was also simply discussed and summarized in the end.

Characterization of Al2O3 and SiC Particles, Reinforced Al Powders, and Plasma Sprayed Wear Resistance Coatings

2000 ◽  
Author(s):  
Fr.-W. Bach ◽  
T. Duda ◽  
Z. Babiak ◽  
P. Bohling ◽  
B. Formanek
Keyword(s):  
Wear Resistance ◽  
Atmospheric Plasma ◽  
Mechanically Alloyed ◽  
Aluminum Coatings ◽  
Hard Particles ◽  
Sic Particles ◽  
Plasma Sprayed ◽  
Aluminum Substrates ◽  
Wear Resistance Coatings

Abstract Aluminum coatings reinforced with either Al2O3 or SiC particles were deposited onto aluminum substrates and subjected to various tests. The coatings were made with mechanically alloyed powders via atmospheric plasma spraying (APS). Both types of coatings had uniformly distributed hard particles, porosities in the range of 4 to 5%, and bond strengths of around 20 MPa. The wear resistance of the SiC-reinforced coatings, however, was almost 35% higher than the coatings containing Al2O3. X-ray examination (XRD) showed that the Al2O3 particles undergo partial phase transformation during spraying, making them more prone to wear.

Wear Resistance of Al2O3, Al2O3-40wt.%TiO2 Coatings Prepared by Plasma Spraying on H13 Hot-Worked Die Steel

2012 ◽  
Vol 538-541 ◽  
pp. 235-238 ◽  
Author(s):  
Ren Guo Song ◽  
Pu Hong Tang ◽  
Chao Wang ◽  
Guo Lu
Keyword(s):  
Wear Resistance ◽  
Plasma Spraying ◽  
Ceramic Coatings ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Die Steel ◽  
X Ray ◽  
Hardness Tester ◽  
Plasma Sprayed ◽  
Scanning Electron

Al2O3 and Al2O3-40wt.%TiO2 ceramic coatings on H13 hot-worked die steel have been prepared by plasma spraying, and then the microstructure, micro-hardness as well as wear resistance of the prepared coatings have been investigated by means of x-ray diffraction (XRD), scanning electron microscope (SEM), Vickers hardness tester and ball-on-disk high temperature tribometer. The results showed that the plasma sprayed ceramic coatings are of higher hardness and wear resistance than H13 hot-worked die steel.

Determination of Abrasive Wear Resistance of Plasma Sprayed Coatings on Stainless Steel Substrate

2015 ◽  
Vol 766-767 ◽  
pp. 579-584 ◽  
Author(s):  
A. Anderson
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Steel Substrate ◽  
Ceramic Coatings ◽  
Atmospheric Plasma ◽  
Wear Behaviour ◽  
Coating Materials ◽  
Plasma Sprayed Coatings ◽  
Plasma Sprayed

A relative study among various types of coating materials to develop wear resistance of stainless steel has been performed. Ceramic coatings with the thickness up to 250 μm were prepared by Atmospheric plasma spray technique on the stainless steel. Two different types of coating materials such that Yttria Stabilised Zirconia, Zirconia Ceria powder were used. The influence of Ceria powder on abrasive wear was determined. It was found that the addition of Ceria to Yttria Stabilised Zirconia in a sufficient amount helped in increasing its wear resistance compared to the wear behaviour of pure Yttria Stabilised Zirconia powder. Moreover, it was found that the lesser the surface roughness of the coating layer,.

Comparative Solid Particle Erosion Characterization of Conventional and Nanostructured Al2O3-13wt.%TiO2 Ceramic Coatings Fabricated by Plasma Spraying Process

2012 ◽  
Vol 463-464 ◽  
pp. 359-363 ◽  
Author(s):  
Dong Sheng Wang ◽  
Zong Jun Tian ◽  
Song Lin Wang ◽  
Li Da Shen
Keyword(s):  
Plasma Spraying ◽  
Solid Particle ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Nanostructured Coating ◽  
Nano Particles ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Nanostructured Ceramic

Abstract. In this work, conventional and nanostructured Al2O3-13wt.%TiO2coatings were deposited by the plasma spraying technique. The microstructures of the two types of coatings were analyzed, and the solid particle erosion behaviors of the two coatings were comparatively researched in an erosion tester. Meanwhile, the erosion failure mechanisms of the coatings were discussed. The results show that the traditional coating has laminated structure and some pores. However, the nanostructured coating possesses a denser structure and not obviously lamellar-like structure, and exhibits a bimodal microstructure consisted of fully melted regions and partially melted regions. Owing to the compact microstructure and remained nano-particles, the nanostructured coating had a better erosion wear resistance than the conventional coating. Eroded morphology analysis indicates the main erosion mass loss of the coatings is attributed to lamellar spalling of the sprayed splats and fracture of brittle ceramic particles. In addition, the nanostructued coating has some impact craters and plough marks. In terms of the erosion mechanism, the conventional ceramic coating is dominated by brittle erosion, while the nanostructured ceramic coating is dominated by brittle erosion as well as ductile erosion to some extent.

Microstructural and Mechanical Characterization of Mechanically-Activated Plasma-Sprayed Nanostructured Al2O3-TiO2 and Al2O3-ZrO2 Coatings

2006 ◽  
Vol 45 ◽  
pp. 1224-1229
Author(s):  
Sandrine Coste ◽  
Ghislaine Bertrand ◽  
Christian Coddet ◽  
Eric Gaffet ◽  
Horst Hahn ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Gas Flow ◽  
Structural Changes ◽  
Mechanical Characterization ◽  
Raw Materials ◽  
Phase Changes ◽  
Atmospheric Plasma ◽  
Plasma Sprayed ◽  
Zirconia Powders

Granulated nanostructured alumina/titania and alumina/zirconia powders were used to achieve coatings by atmospheric plasma spraying. Raw materials and mechanically activated ceramic mixtures (alumina with 13wt% and 44wt% of titania or 40wt% and 80wt% of zirconia) have been considered to produce the sprayable powders. Effects of various plasma spray conditions (primary Ar and secondary H2 gas flow rates, arc intensity) on the microstructure, phase content and microhardness of the coatings have been evaluated. It has been shown by SEM observations that the coatings exhibit a lamellar structure consisting in fully melted and partially melted areas including porosity, ranging from 10 to 30vol.%. The phase changes (from αAl2O3 to γAl2O3, from anatase to rutile for TiO2, Al2TiO5) or structural changes that occur during the plasma spraying of the nanostructured powders were investigated by XRD and related to the processing conditions and in turn to the amount of unmelted powder.

Electron microscopy studies of plasma-sprayed materials

1983 ◽  
Vol 41 ◽  
pp. 70-71
Author(s):  
K.R. Subramanian ◽  
A.H. King ◽  
H. Herman
Keyword(s):  
Plasma Spraying ◽  
Substrate Surface ◽  
Flame Temperature ◽  
Ceramic Coatings ◽  
Metallic Substrates ◽  
Hot Plasma ◽  
Almost All ◽  
Plasma Sprayed ◽  
Hostile Environments ◽  
Plasma Spraying Process

Plasma spraying is a technique which is used to apply coatings to metallic substrates for a variety of purposes, including hardfacing, corrosion resistance and thermal barrier applications. Almost all of the applications of this somewhat esoteric fabrication technique involve materials in hostile environments and the integrity of the coatings is of paramount importance: the effects of process variables on such properties as adhesive strength, cohesive strength and hardness of the substrate/coating system, however, are poorly understood.Briefly, the plasma spraying process involves forming a hot plasma jet with a maximum flame temperature of approximately 20,000K and a gas velocity of about 40m/s. Into this jet the coating material is injected, in powder form, so it is heated and projected at the substrate surface. Relatively thick metallic or ceramic coatings may be speedily built up using this technique.

scholarly journals Microstructure and Wear Behavior of Plasma-Sprayed TiO2–SiAlON Ceramic Coating

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1268
Author(s):  
Yun Wang ◽  
Weichao Wan ◽  
Junhong Mao ◽  
Lihui Tian ◽  
Ruitao Li
Keyword(s):  
Ceramic Coating ◽  
Wear Behavior ◽  
Rutile Phase ◽  
Atmospheric Plasma ◽  
Tio2 Anatase ◽  
Sialon Ceramic ◽  
Mating Surface ◽  
Starved Lubrication ◽  
Plasma Sprayed ◽  
Lubrication Conditions

In this study, atmospheric plasma spray was employed to deposit TiO2–SiAlON ceramic coating on 316 stainless steel. The phases and microstructure of the ceramic coating were investigated. Additionally, comparative studies on the tribological performances of the substrate and the ceramic coating, under both dry and starved lubrication conditions, were carried out. The SiAlON phase was preserved, while partial TiO2 anatase was transformed to rutile phase. The wear rate of the coating was roughly 1/3 of that of the substrate under both conditions. The wear mechanisms of the ceramic coating were surface fracture and abrasive wear in both cases, and the coating under starved lubrication underwent less abrasion. The pores in the coating served as micro-reservoirs, forming an oil layer on the mating surface, and improving tribological properties during sliding.

Plasma Spraying of Self-Lubricating Cr2O3-CaF2 Coatings

1997 ◽  
Author(s):  
F. Vos ◽  
L. Delaey ◽  
M. De Bonte ◽  
L. Froyen
Keyword(s):  
Plasma Spraying ◽  
Matrix Material ◽  
Production Method ◽  
Atmospheric Plasma ◽  
Spray Parameters ◽  
The Matrix ◽  
Preparation Step ◽  
Plasma Sprayed ◽  
The Relationship ◽  
Selection Of

Abstract Results are presented of a project analysing the relationship between the production parameters of plasma sprayed self-lubricating Cr2O3-CaF2 coatings and their structural, wear and lubricating properties. The production method consists of a preparation step where a powder blend of the matrix material (Cr203) and solid lubricant (CaF2) is agglomerated, followed by atmospheric plasma spraying (APS) of the agglomerates. Selection of the most appropriate agglomeration and plasma spray parameters as well as the microstructure of the coatings will be discussed.

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