Experimental Approach to Adhesion between an Alumina Plasma-Sprayed Coating and Polymeric Substrate

1996 ◽  
Author(s):  
P. Lucchese ◽  
R. Jeandin ◽  
G. Surdon ◽  
A. Delavernme
Keyword(s):  
Bond Coat ◽  
Surface Preparation ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Fiber Layer ◽  
Bond Coats ◽  
Reinforced Polymer ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Thermally Sprayed

Abstract Thermal spray coating of fiber reinforced polymer (FRP) components has a high development potential to improve their wear, erosion and corrosion resistance. This paper deals with the optimization of plasma spraying conditions of alumina onto a FRP substrate, including the study of surface preparation. The so-called "Atmosphere and Temperature Controlled Process (ATC, patented by CEA)" was used to maintain the substrate temperature at a rather low level, i.e. near room temperature. Various surface preparation processes such as grit blasting, cleaning using the plasma torch and pre-coating with an intermediate bond coat were tested. The latter was shown to improve adhesion between the coating and the substrate significantly, when using 2 types of bond coats. One consisted of an additionnal fiber layer directly stuck to the substrate, the other of an intermediate thermally-sprayed PEEK layer. Results of adhesion tests were discussed in the light of interface characterization. Using a PEEK bond coat led to an adhesion strength between alumina and the substrate 3 times better than that for the material without any bond coat.

scholarly journals Influence of Different Annealing Atmospheres on the Mechanical Properties of Freestanding MCrAlY Bond Coats Investigated by Micro-Tensile Creep Tests

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 692 ◽  
Author(s):  
Sven Giese ◽  
Steffen Neumeier ◽  
Jan Bergholz ◽  
Dmitry Naumenko ◽  
Willem J. Quadakkers ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Creep Strength ◽  
Bond Coat ◽  
Oxide Dispersion Strengthened ◽  
Tensile Creep ◽  
Creep Tests ◽  
Bond Coats ◽  
Nial Phase ◽  
Lower Strain ◽  
Plasma Sprayed

The mechanical properties of low-pressure plasma sprayed (LPPS) MCrAlY (M = Ni, Co) bond coats, Amdry 386, Amdry 9954 and oxide dispersion strengthened (ODS) Amdry 9954 (named Amdry 9954 + ODS) were investigated after annealing in three atmospheres: Ar–O2, Ar–H2O, and Ar–H2–H2O. Freestanding bond coats were investigated to avoid any influence from the substrate. Miniaturized cylindrical tensile specimens were produced by a special grinding process and then tested in a thermomechanical analyzer (TMA) within a temperature range of 900–950 °C. Grain size and phase fraction of all bond coats were investigated by EBSD before testing and no difference in microstructure was revealed due to annealing in various atmospheres. The influence of annealing in different atmospheres on the creep strength was not very pronounced for the Co-based bond coats Amdry 9954 and Amdry 9954 + ODS in the tested conditions. The ODS bond coats revealed significantly higher creep strength but a lower strain to failure than the ODS-free Amdry 9954. The Ni-based bond coat Amdry 386 showed higher creep strength than Amdry 9954 due to the higher fraction of the β-NiAl phase. Additionally, its creep properties at 900 °C were much more affected by annealing in different atmospheres. The bond coat Amdry 386 annealed in an Ar–H2O atmosphere showed a significantly lower creep rate than the bond coat annealed in Ar–O2 and Ar–H2–H2O atmospheres.

Influence of Surface Condition on the Bonding Strength of Thermal Sprayed Coatings

1997 ◽  
Author(s):  
V.Yu. Ulianitsky ◽  
J.A. Nikolaev ◽  
T.P. Gavrilenko ◽  
M.C. Kim ◽  
J.W. Hong
Keyword(s):  
Bonding Strength ◽  
Substrate Surface ◽  
Surface Condition ◽  
Surface Preparation ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Substrate Material ◽  
Detonation Spraying ◽  
Wide Scale ◽  
Detonation Gun

Abstract The role of surface roughness in coating adhesion mechanism is studying for detonation spraying. Roughness was produced by conventional grit blasting, D-gun blasting and was formed as a result of spraying of high-adhesive thin layer of detonation coating. Cermet and alloy powders were sprayed by detonation gun Ob. The coating bonding strength measurements show the WC+25Co adhesion to be above 200 MPa independently of a substrate surface preparation. Contrary, NiCrSiB coatings are very sensitive to surface conditions their adhesion varies from 180 MPa to zero. As-sprayed alloy particles fail in adherence because of insufficient energy to fuse substrate material at a flat surface. Only developed (wide scale) roughness may be fused partially by these particles for their bonding to the substrate. Otherwise, high heated cermet particles do not need special surface preparation (except cleaning) for fusion of substrate material to provide high bonding with it. The wide scale and ball shape roughness, which is similar to the self-reproduced coating roughness, provides the best conditions for the coating bonding and it is recommended as the purpose of surface treatment before thermal spray coating.

Splashing of Nickel Droplets During Plasma Spraying

2000 ◽  
Author(s):  
V. Pershin ◽  
I. Thomson ◽  
S. Chandra ◽  
J. Mostaghimi
Keyword(s):  
Substrate Temperature ◽  
Nickel Powder ◽  
Steel Substrate ◽  
Spray Coating ◽  
Building Blocks ◽  
Thermal Spray Coating ◽  
Substrate Heating ◽  
Polished Stainless Steel ◽  
Plasma Sprayed ◽  
Droplet Impacts

Abstract Individual splats are the building blocks of any thermal spray coating. Near the coating-substrate interface, they affect coating properties like adhesion strength. This article examines the effect of substrate heating on droplet splashing. Nickel powder was plasma-sprayed onto a polished stainless steel substrate at various temperatures and the resulting splats were analyzed. Droplet splashing was observed experimentally for three different cases: low substrate temperature, high substrate temperature, and droplet-splat interaction. Mechanisms for splashing were explained with the help of computer-generated nickel droplet impacts. The article proposes that the jetting of molten metal is not triggered by the formation of a central splat but rather a solidified ring on the periphery of the splat. It was observed that, on substrates below 350 deg C, splashing is triggered by solidification at the edge of the spreading droplet. Interactions with previously deposited splats also cause droplets to splash.

Residual Stress Measurement of Plasma Sprayed Coating Layers in ZrO2

2007 ◽  
Vol 544-545 ◽  
pp. 451-454
Author(s):  
Soo Wohn Lee ◽  
Jia Zhang ◽  
Huang Chen ◽  
J. S. Song ◽  
Jae Kyo Seo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Diffraction Method ◽  
Spray Coating ◽  
X Ray Diffraction ◽  
Plasma Sprayed Coatings ◽  
Coating Layers ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Sprayed Coatings

Plasma sprayed coatings have been widely applied in modifying surface properties of metal components. It is also useful to prevent various types of wear, corrosion, erosion and thermal. But the residual stress is still an important problem which can effect the properties of sprayed coating. So it’s necessary to find out the reason of residual stress and the relationship between plasma sprayed condition and residual stress. Plasma spray coating layers with conventional ZrO2 powder was examined to calculate residual stress by X-ray diffraction method with various coating thickness.

scholarly journals Influence of Laser-Assisted Fusing on Microstructural Evolution and Tribological Properties of NiWCrSiB Coating

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 548 ◽  
Author(s):  
Changkyoo Park ◽  
Eun-Joon Chun
Keyword(s):  
Spray Coating ◽  
Thermal Spray Coating ◽  
Temperature Control System ◽  
Secondary Phases ◽  
Hardening Behavior ◽  
Transmission Electron ◽  
Transmission Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
Sprayed Coating ◽  
M23c6 Carbides

The present study examines the applicability of a diode laser-assisted fusing treatment and a temperature-control system to the NiWCrSiB thermal spray coating to develop the enhanced wear resistance of continuous-casting molds. As a result of the use of the lasers, the variations in the microstructure and the hardening behavior during the fusing treatment could be controlled. Fine secondary phases (approximately 0.05–10 μm in size) homogeneously present in the coating after the laser-assisted fusing were observed to be Cr-, Mo- and W-based carbides and borides. Transmission electron microscope analysis was used to characterize these fine secondary phases as M7C3 and M23C6 carbides and M5B3 boride. Because of these fine secondary phases, the hardness increased from 730 (as-sprayed status) to 1230 HV (after fusing at a temperature of 1473 K). Finally, given the formation of fine secondary phases and the occurrence of surface hardening, the laser-assisted fusing treatment was deemed to enhance the tribological performance of the thermal-sprayed coating, in that it exhibited a lower coefficient of friction and lower wear rate than the as-sprayed coating.

The Comparison Study on Abrasive and Erosive Resistance Properties of Thermal Spray Coatings

2020 ◽  
Vol 901 ◽  
pp. 49-54
Author(s):  
Jirasak Tharajak ◽  
Noppakun Sanpo
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Spray Coating ◽  
Solid Material ◽  
Thermal Spray Coating ◽  
Comparison Study ◽  
Spray Coatings ◽  
Wide Range ◽  
Resistance To Wear ◽  
Sprayed Coating

Thermal spraying is a technology which improves and restores the surface of a solid material. The process can be used to apply coatings to a wide range of materials and components, in order to provide resistance to wear, erosion, cavitation, corrosion, abrasion or heat. In this paper, the study of abrasive and erosive properties of Cr3C2/20%NiCr and FeCrB + Al thermal sprayed coating samples were focused. It was revealed that both received thermal spray coating samples show outstanding abrasive and erosive resistance properties.

Electrical Properties of Half Heusler Coatings Depending on Spray Process

2021 ◽  
Author(s):  
Geoffrey Darut ◽  
Axel Portebois ◽  
Ludovic Vitu ◽  
Marie Pierre Planche ◽  
Hanlin Liao ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Electrical Properties ◽  
Practical Interest ◽  
Coating Properties ◽  
Spray Process ◽  
Coating Composition ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
P Type ◽  
Thermally Sprayed

Abstract Microstructure and physicochemical properties of a thermally sprayed coating depend on the dynamics of the particles interacting with the spray jet. This is especially the case for electrical properties. In this study, different spraying processes were used to spray p-type and n-type half-Heusler powders. Thermoelectric powders, Hf20Zr75Ti05CoSb80Sn20 (p-type) and Hf60Zr40NiSn98Sb02 (n-type), were selected due to their interesting electrical properties. The spray processes were evaluated based on coating composition and mechanical property measurements. The only coatings of practical interest were those that were plasma sprayed and they were examined in detail to assess the effect of process parameters on coating properties.

Local Approach to Thermally-Sprayed Coating/Substrate Adhesion through LASAT (Laser Shock Adhesion Test)

2007 ◽  
Vol 539-543 ◽  
pp. 1067-1073
Author(s):  
Sophie Barradas ◽  
Michel Jeandin ◽  
Régine Molins ◽  
F. Borit ◽  
L. Berthe ◽  
...  
Keyword(s):  
Cold Spray ◽  
Spray Coating ◽  
Local Approach ◽  
Small Areas ◽  
Substrate Adhesion ◽  
Cold Spray Coating ◽  
Sprayed Coating ◽  
Thermally Sprayed ◽  
Sprayed Coatings ◽  
Rapid Deformation

Three interface factors may influence thermally-sprayed coatings adhesion: interface morphology (as usual), thermal and chemical features. It was shown that these three aspects of adhesion mechanisms are shown to be dependent and very local. It is especially true for cold spray which is one of the most promising spray processes. As this spraying technique is based on rapid deformation, cold spray coating/substrate interfaces show local morphological, thermal and chemical features, in a way that none of them can be neglected. LASAT is particularly suitable for testing these coatings because it can be applied to small areas (~1 mm²). From this, it has the outstanding advantage to be sensitive to fine-scaled phenomena responsible for coating adhesion.

Study on Microstructure of Nano-Zirconia Coating by Atmospheric Plasma Spraying

2014 ◽  
Vol 618 ◽  
pp. 43-49
Author(s):  
Ying Chang ◽  
Qin Biao Zhu ◽  
Shi Jie Dong ◽  
Hui Hu Wang ◽  
Kuan He Du
Keyword(s):  
Electron Microscopy ◽  
Layer Structure ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Ceramic Particle ◽  
Atmospheric Plasma ◽  
Zirconia Coating ◽  
Technical Parameters ◽  
Columnar Grains ◽  
Plasma Sprayed

On the basis of successfully preparing nanozirconia coating via reasonable spraying technical parameters, the cross section and surface morphology of coating were determined by scan electron microscopy (SEM), and the ceramic particle sizes of coating were determined by transmission electron microscopy (TEM). Experimental results indicate that plasma sprayed zirconia coating possesses typical layer structure of thermal spray coating, in which columnar grains pile up together. Meanwhile, the non-molten nanopowders coexist with the layer structure. In addition, the equiaxial grains exist in the zirconia coating according to TEM, but the grain size is not uniform.

Thermal Spray Coatings for Fiber Reinforced Polymer Composites

1998 ◽  
Author(s):  
A.A. Ashari ◽  
R.C. Tucker
Keyword(s):  
Polymer Composites ◽  
Thermal Spray ◽  
Bond Coat ◽  
Thermal Spray Coatings ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Bond Coats ◽  
Spray Coatings ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites

Abstract Fiber reinforced polymer composites are an important class of structural materials. They possess high strength-to-weight ratios and high rigidities. However, for man ' applications heir wear resistance is less than desirable. Wear resistant thermal spray coatings can enhance the surface of these materials. Coatings on some composites have satisfactory adhesion without a bond coat, but others needed an appropriate bond coat. Polymer and o her bond coats have been used to enhance he adhesion of thermal spray coatings on composites. The present study was conducted to find one or more suitable bond coat materials. Materials such as polyamides, polyimides, polyether-etherketone or simply aluminum or nickel were found to be suitable bond coats for man ' different composite substrates.

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