Nano-SiC Modified Plasma Sprayed Ceramic Coatings Prepared by Laser Sintering

2008 ◽  
Vol 375-376 ◽  
pp. 348-352 ◽  
Author(s):  
Zong Jun Tian ◽  
Li Da Shen ◽  
Yin Hui Huang ◽  
Guo Ran Hua
Keyword(s):  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Laser Sintering ◽  
Laser Remelting ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Coating ◽  
Plasma Sprayed ◽  
Steel Substrates ◽  
Electronic Microscope

This paper describes an investigation of nano-SiC reinforced ceramic coating, which has included NiCrAl and Al2O3+13wt%TiO2 coatings pre-produced by atmosphere plasma spraying, implemented by laser sintering. Commercial NiCrAl powders were plasma sprayed onto 45 steel substrates to produce a bond coating with thickness of ~100μm. The Al2O3-TiO2 based coating with ~500μm thickness was then plasma sprayed on top of the NiCrAl bond coating. With CO2 laser, nano-SiC powders were laser sintered on Al2O3-TiO2 based coatings. The microstructure and chemical composition of the modified based coatings were analyzed by such detection devices as scanning electronic microscope (SEM) and x-ray diffraction (XRD). The results show that the size of SiC grains has no obvious growth. In addition, due to the nanostructured SiC phase and laser remelting, the modified coatings exhibited better abrasion resistance than those unmodified samples.

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.

Anti-Wear Coating Grown by Micro-Plasma Oxidation on Aluminum Alloys in the Solution of Aluminate-Titania

2011 ◽  
Vol 239-242 ◽  
pp. 667-670 ◽  
Author(s):  
Li Gong Zhang ◽  
Gui Mei Zhao ◽  
Xiao Ming Lai
Keyword(s):  
Aluminum Alloys ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Wear Property ◽  
Plasma Oxidation ◽  
X Ray Diffraction ◽  
Electrolytic Solution ◽  
X Ray ◽  
Hardness Tester ◽  
Wear Coating

In this paper, Aluminum trioxide ceramic coatings were grown on surfaces of 2024 Aluminum alloys by micro-plasma oxidation in an aluminate electrolytic solution. In order to decrease the density of the pores and increase the anti-wear property of the ceramic coatings, Titania were added into the aluminate electrolytic solution. The struture and anti-wear property of the produced ceramic coatings were measured by X-ray diffraction, scanning electron microscope , hardness tester and frictionometer. The results show that the thickness of the ceramic coating is about 24±1 μm, surfaces of the ceramic coatings are very uniform. The hardness of the doped coating is up to 930 HV, and the wear property of the coating is the more excellent than that of undoped coating.

Thermal Barrier Effects Comparison of Plasma-Sprayed and Laser-Remelted Al2O3-13 % TiO2 Ceramic Coatings

2014 ◽  
Vol 978 ◽  
pp. 40-43
Author(s):  
Dong Sheng Wang ◽  
Guang Qu ◽  
Jin Lan Su
Keyword(s):  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Nanostructured Coating ◽  
Thermal Barrier ◽  
Heat Current ◽  
Barrier Effect ◽  
Laser Remelting ◽  
Plasma Sprayed ◽  
Sprayed Coatings ◽  
Conventional Coating

Conventional and nanosturctured Al2O3–13 wt% TiO2ceramic coatings were deposited by plasma spraying on TiAl alloy surface. Laser remelting experiment on as-sprayed coatings was carried out and the influences of laser remelting on microstructure and thermal barrier effect of the coating were researched. The results show that the as-sprayed conventional coating has a typical plasma-sprayed lamellar-like structure, while the nanostructured coating consisted of both fully melted regions and partially melted regions. The laser-remelted conventional coating exhibits column-like crystals which grew along the direction of the heat current, while the nanostructured coating composed of fine equiaxed grains with some remained nanoparticles. The nanostructured ceramic coating has higher thermal barrier effect than the conventional ceramic coating does. The thermal barrier effect of the as-sprayed coatings decreases after laser remelting.

Characterization of Plasma Sprayed Yittria Stabilized Zirconia (8 wt %) Hydroxyapatite Coatings

2011 ◽  
Vol 493-494 ◽  
pp. 535-538
Author(s):  
O. Anzabi ◽  
M.M. Aydin ◽  
L.S. Ozyegin ◽  
F.N. Oktar ◽  
Kārlis A. Gross ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Pure Titanium ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Bond Coatings ◽  
Bond Coating ◽  
Bond Layer ◽  
Diffraction Patterns ◽  
Plasma Sprayed

Splitting problems at HA-coated implants are generally due to biological reasons. Bond-coatings were used to prevent the splitting problem of zirconia ceramics; this method can be widely seen in industrial applications. Two main groups were used; the first group consisted of spraying a bond layer of titania onto commercially pure titanium. This followed by a spray of HA with 5, 10 and 15 % zirconia (8 % yttria doped) as main layer onto the first bond-coating. For the second group, the samples were coated without bond-coating. Firstly, X-ray diffraction patterns of the starting powders were taken. Then x-ray diffraction patterns of the plasma sprayed samples were taken. In literature, it was seen that 20 % zirconia was sufficient for the transformation into a monoclinic structure for the bond-coated samples. For this study it was found that 10 % zirconia was sufficient to transform to the same structure of the desired crystalline phase transformation. The coating kept its crystal structure and relatively small amount of amorphous transformation was detected. A similar structure was produced using less zirconia. It was thought that the use of titanium-oxide bond-coating layer would play an important role as a third variable in the results. To further investigate these phenomena, more detailed researches must be conducted with using titanium-oxide yittria stabilized zirconia (8 wt %) hydroxyapatite bond-coatings with HA main coatings.

Properties of Multi-Function Micro-Plasma Sprayed Nanostructured Al2O3-13wt%TiO2 Coatings

2008 ◽  
Vol 373-374 ◽  
pp. 59-63
Author(s):  
Liu Ying Wang ◽  
Gu Liu ◽  
Han Gong Wang ◽  
Shao Chun Hua
Keyword(s):  
Mechanical Properties ◽  
Plasma Spray ◽  
Bonding Strength ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tensile Tester ◽  
Powder Particles ◽  
Plasma Sprayed ◽  
Electronic Microscope ◽  
Microhardness Tester

Nonastructured Al2O3-13wt%TiO2 (AT13) coatings were deposited by multi-function micro-plasma spray and Metco 9M plasma spray, respectively. Constituent phases and the microstructure of the powder particles and coatings prepared were examined with the aid of scanning electronic microscope (SEM) and X-ray diffraction (XRD). Mechanical properties including hardness and bonding strength were also evaluated by microhardness tester and electron tensile tester. Multi-function micro plasma sprayed nanostructured AT13 Coating is fully-melted, dense and uniform. However, AT13 Coating deposited by Metco 9M plasma spray is partial-melted. The microhardness of multi-functional micro plasma sprayed AT13 Coating is HV975.7~1441.7, much higher than that of Metco 9M plasma sprayed AT13 Coating (HV655.3~946.6). The bonding strength results present the same, increased from 19.8 MPa to 42.7 MPa.

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.

Residual Stress Characteristics of Plasma Sprayed CoNiCrAlY Coatings by X-Ray Diffraction

2007 ◽  
Vol 353-358 ◽  
pp. 495-498 ◽  
Author(s):  
Hiroyuki Waki ◽  
Akira Kobayashi
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Plasma Spraying ◽  
Expansion Coefficient ◽  
Bending Test ◽  
Powder Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sprayed ◽  
Steel Substrates

Plasma sprayed CoNiCrAlY coating can prevent oxidation and corrosion of turbine blades in a gas turbine plant. Cracking and delamination of coatings are affected by the residual stresses in the coatings. In this study, the arising mechanism of residual stress in the plasma sprayed coating was discussed. The residual stresses in CoNiCrAlY coatings were measured by X-ray diffraction method. The coatings were deposited by either low pressure plasma spraying (LPPS) or atmospheric plasma spraying (APS). Each elastic constant which was used for determining the X-ray stress constant was mechanically measured by a bending test. Two kinds of substrates were prepared for each coating in order to examine the effect of thermal expansion coefficient of a substrate. Results were as follows. The residual stresses of the coatings on steel substrates were tensile. On the other hand, the residual stresses on stainless substrates were lower than those on steel substrates. Arising mechanism of the residual stresses can be explained by both the linear expansion coefficient and the range of changing temperature. It was also found that the absolute residual stresses were affected by the spraying powder size and increased with a decrease of the spraying powder size. It was principally caused by the difference in the elastic constants.

Study in performance and morphology of polyamide 12 produced by selective laser sintering technology

2018 ◽  
Vol 24 (5) ◽  
pp. 813-820 ◽  
Author(s):  
Junjie Wu ◽  
Xiang Xu ◽  
Zhihao Zhao ◽  
Minjie Wang ◽  
Jie Zhang
Keyword(s):  
Selective Laser Sintering ◽  
Polarized Light ◽  
Chain Scission ◽  
High Energy ◽  
Laser Sintering ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Content Type ◽  
X Ray ◽  
Polyamide 12

Purpose The purpose of this paper is to investigate the effect of selective laser sintering (SLS) method on morphology and performance of polyamide 12. Design/methodology/approach Crystallization behavior is critical to the properties of semi-crystalline polymers. The crystallization condition of SLS process is much different from others. The morphology of polyamide 12 produced by SLS technology was investigated using scanning electron microscopy, polarized light microscopy, differential scanning calorimetry, X-ray diffraction and wide-angle X-ray diffraction. Findings Too low fill laser power brought about bad fusion of powders, while too high energy input resulted in bad performance due to chain scission of macromolecules. There were three types of crystal in the raw powder material, denoted as overgrowth crystal, ring-banded spherulite and normal spherulite. Originality/value In this work, SLS samples with different sintering parameters, as well as compression molding sample for the purpose of comparison, were made to study the morphology and crystal structure of sintered PA12 in detail.

Structure and Electrochemical Behavior of Plasma-Sprayed LSGM Electrolyte Films

2002 ◽  
Vol 756 ◽  
Author(s):  
H. Zhang ◽  
X. Ma ◽  
J. Dai ◽  
S. Hui ◽  
J. Roth ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Amorphous Structure ◽  
Solid Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Electrolyte Film ◽  
Plasma Sprayed

ABSTRACTAn intermediate temperature solid oxide fuel cell (SOFC) electrolyte film of La0.8Sr 0.2Ga0.8Mg0.2O2.8 (LSGM) was fabricated using a plasma spray process. The microstructure and phase were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the thermal sprayed LSGM film was investigated using electrochemical impedance spectroscopy (EIS). The study indicates that thermal spray can deposit a dense LSGM layer. It was found that the rapid cooling in the thermal process led to an amorphous or poor crystalline LSGM deposited layer. This amorphous structure has a significant effect on the performance of the cell. Crystallization of the deposited LSGM layer was observed during annealing between 500–600 °C. After annealing at 800 °C, the ionic conductivity of the sprayed LSGM layer can reach the same level as that of the sintered LSGM.

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