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.

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.

Simulation and Experimental Study of the Coupling Drive Magnetic Field for Embedded Giant Magnetostrictive Actuators

2012 ◽  
Vol 510 ◽  
pp. 322-327
Author(s):  
Bin Wang ◽  
Yi Jie Wu ◽  
Lei Zhang
Keyword(s):  
Magnetic Field ◽  
Matrix Material ◽  
Experimental Tests ◽  
High Frequencies ◽  
Output Displacement ◽  
Close Relationship ◽  
The Matrix ◽  
Magnetostrictive Actuators ◽  
Magnetostrictive Actuator ◽  
The Relationship

Embedded giant magnetostrictive actuator (EGMA) is one of the most important applications of magnetostrictive material. Giant magnetostrictive actuators can deliver big-output displacement and can be driven at high frequencies. These characteristics make them suitable for a variety of positioning. However, because of the limitation of structure, the drive coil and EGMA cannot be any size as needed, so how to maximize the displacement in the limitative situation by optimization becomes the key of design. Several methods are available in the literature, but the coupling drive magnetic field of EGMA and its matrix material is often ignored. In fact, there was a close relationship between the matrix material and the distribution of drive magnetic field. To analyze the relationship, this paper establishes the magnetic circuit model for EGMA. The simulation of the coupling drive magnetic field is also presented. Finally the assumption is validated through experimental tests carried out with two different matrix materials.

Elements and Materials Improve the FDM Products: A Review

2016 ◽  
Vol 16 ◽  
pp. 33-51 ◽  
Author(s):  
Abduladim Salem Bala ◽  
Saidin bin Wahab ◽  
Mazatusziha binti Ahmad
Keyword(s):  
Matrix Material ◽  
Process Parameter ◽  
Correct Selection ◽  
Complex Environment ◽  
Technology Process ◽  
The Matrix ◽  
Additive Materials ◽  
Insight Into ◽  
Selection Of

This work aims to provide a review of available published literature that explores the opportunities to improve the quality of fused deposit modelling (FDM) products, particularly in medical applications. The paper presents details concerning the basis of the technology, process parameter settings and their responses, and reviews the properties of common FDM engineering/bio-materials and the available methods applied for improving their performance. Based on the researches which have been reviewed, FDM technology works within a complex environment from process parameters. Thus, it can achieve good results only with the proper settings for these parameters according to the properties of the material used. Improving the polymers is essentially based on the correct selection of additive materials, which can particularly enhance the key property/properties in the matrix material. This review provides a brief insight into FDM technology, provides an idea of the process parameter settings, the available materials and ways of modifying their properties to consequently improve the quality of FDM products.

Dielectric and Infrared Properties of Plasma Sprayed Nano β-SiC/ Al2O3 Agglomerate Composite Absorbing Coatings

2013 ◽  
Vol 634-638 ◽  
pp. 1901-1905
Author(s):  
Xiao Jing Yuan ◽  
Bai Lin Zha ◽  
Han Gong Wang
Keyword(s):  
Dielectric Properties ◽  
Plasma Spraying ◽  
Low Frequency ◽  
Threshold Value ◽  
Al2o3 Composite ◽  
Plasma Sprayed ◽  
The Relationship

In this paper, the nano-β-SiC/Al2O3 composite absorbing coatings produced by plasma spraying technology were reported. Where, β-SiC phase dissipates in the boundary of Al2O3 grains. Then, the relationship between microstructure and dielectric properties was built. Some results are shown as follows: with increasing of flatten ratio of particle and pores, the microwave reflectivity coefficient of composite absorbing coatings decreases and ranges to low frequency. And, there exists a threshold value, about 30wt% of nano β-SiC, the microwave reflectivity coefficient of composite absorbing coatings can reach to -8 dB. The infrared properties of β-SiC/ Al2O3composite absorbing coatings with experiment is about 0.6~0.8, respectively.

Microstructure and Abrasive Wear Properties of Plasma Sprayed Nanostructured Al2O3-TiO2-ZrO2-CeO2 Coatings

2011 ◽  
Vol 291-294 ◽  
pp. 117-124
Author(s):  
Wei Qin Wu ◽  
Qiang Li ◽  
Zhen Yi Wei ◽  
Hui Ye
Keyword(s):  
Bond Strength ◽  
Plasma Spraying ◽  
Plasma Spray ◽  
Normal Load ◽  
Liquid Phase Sintering ◽  
Orthogonal Experimental Design ◽  
Spray Parameters ◽  
Wear Properties ◽  
Spalling Fracture ◽  
Plasma Sprayed

Al2O3-TiO2-ZrO2-CeO2 coatings formed via a plasma spray approach. The optimal spray parameters of plasma sprayed nano-structured coating were determined by orthogonal experimental design, based on porosity, bond strength of the coatings and the partly melted(PM) zone percentage. Microstructure of the plasma sprayed nanostructured Al2O3-TiO2-ZrO2-CeO2 coating sprayed on the optimal spray parameters was analyzed. Wear map was established by wear experiments. The results show, nanostructured coating contains fully melted (FM) zone and PM zone, the increasing of the critical plasma spray parameter (CPSP) promote the decreasing of the PM zone percentage and the increasing of the bond strength of the coatings. The composition phases of the powder reacted to each other during the plasma spraying process. FM and PM zone resulted from fully melted droplets and partly melted particles respectively. Nanosized crystals and amorphous particles exist in the PM zone, liquid phase sintering is taken place in the PM zone. The main wear mechanism of plasma spraying coatings are plastic deformation and microplow, microfracture and grain spalling, fracture and delamination at different normal load and sliding speed in dry friction.

The Role of Different Atmospheric Plasma Spray Parameters on Microstructure of Abradable AlSi-Polyester Coatings

2017 ◽  
Vol 270 ◽  
pp. 224-229
Author(s):  
David Jech ◽  
Ladislav Čelko ◽  
Pavel Komarov ◽  
Jindřich Ziegelheim ◽  
Zdeněk Česánek ◽  
...  
Keyword(s):  
Deposition Efficiency ◽  
Atmospheric Plasma ◽  
Spray Parameters ◽  
Technological Parameters ◽  
Coating Microstructure ◽  
Two Parameters ◽  
Plasma Sprayed ◽  
Abradable Coatings ◽  
And Control

One of the approaches to increase the thermic efficiency of aerospace engines is the application of abradable coatings enabling minimization and control of the clearance between the stator and the rotating blades tips. The main purpose of this contribution is to define the role of different technological parameters utilized for atmospheric plasma spraying of AlSi-polyester coating on its resulting microstructure. Deposition of abradable coatings on the real engine parts is mostly dependent on spraying stand-off distance and on spraying angle. These two parameters influence not only the coating microstructure but also the deposition efficiency itself, which is directly connected with economical aspects of the coating production. The set of experimental samples with atmospheric plasma sprayed Ni-based bond coat and two in chemical composition same initial powders delivered from different powder manufacturers were used to spray thick AlSi-polymer top coats with different spraying stand-off distances and angles. Subsequently some of the samples were also heat treated to burn-out the polymer phase from the coating microstructure. The Rockwell HR15Y hardness was measured on all samples and the microstructure and coating thickness were evaluated by means of light microscopy and image analysis methods.

THE INFLUENCE OF ENVIRONMENTAL EFFECTS ON THE ACOUSTIC PHONON SPECTRA IN QUANTUM-DOT HETEROSTRUCTURES

2002 ◽  
Vol 12 (04) ◽  
pp. 1147-1158 ◽  
Author(s):  
SALVADOR RUFO ◽  
MITRA DUTTA ◽  
MICHAEL A. STROSCIO
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Environmental Effects ◽  
Phonon Spectrum ◽  
Acoustic Phonon ◽  
Matrix Material ◽  
Free Standing ◽  
Phonon Spectra ◽  
The Matrix ◽  
Selection Of

We present calculations of the acoustic phonon spectra for a variety of quantum dots and consider the cases where the quantum dots are both free-standing and embedded in a selection of different matrix materials — including semiconductors, plastic, and water. These results go beyond previous calculations for free-standing quantum dots and demonstrate that the matrix material can have a large effect on the acoustic phonon spectrum and consequently on a variety of phonon-assisted transitions in quantum-dot heterostructures.

scholarly journals Sensitivity of Process Parameters in Atmospheric Plasma Spray Coating

2018 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Biswajit Kumar Swain ◽  
◽  
Soumya Sanjeeb Mohapatra ◽  
Ashutosh Pattanaik ◽  
Sumant Kumar Samal ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Process Parameters ◽  
Spray Coating ◽  
Correct Choice ◽  
Atmospheric Plasma ◽  
Spray Parameters ◽  
Substrate Roughness ◽  
Working Pressure ◽  
Plasma Gun ◽  
Wide Range

Atmospheric plasma spraying (APS) is one of the most widely used thermal spraying technique which finds a lot of applications due to its versatility of spraying a wide range of materials from metallic to nonmetallic and hence more suitable for spraying of high melting point materials like refractory ceramics material, cermets etc. In recent era,any material can be used for plasma spraying on almost any type of substrate. Process parameters are the key factor that affects the formation of microstructures, bonding of coating with substrate and mechanical strength of coating. In this paper, the process parameters and their sensitivity towards the plasma modified structural elements are discussed.The microstructure of thermally sprayed coatings, which results from the solidification and sintering of the particles, frequently contain pores, oxides and cracks. The amount and distribution of these defects, as well as other coating properties as for instance thickness, hardness and bond strength, will be defined by the selected spray parameters. Therefore, the correct choice of the spray process as well as respective parameters (particle size, particle velocity, spray distance, plasma gun power, working pressure, substrate roughness, substrate temperature and so on) is very important for the deposition of good coatings and, consequently, to enlarge the useful life in service of the components.

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.

Sign in / Sign up

Export Citation Format

Share Document