• Title/Summary/Keyword: Plasma Spray Coating

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Evaluation of Plasma Spray Hydroxy Apatite coatings on Metallic Materials

  • Take, S.;Mitsui, K.;Kasahara, M.;Sawai, R.;Izawa, S.;Nakayama, M.;Itoi, Y.
    • Corrosion Science and Technology
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    • v.6 no.6
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    • pp.286-290
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    • 2007
  • Biocompatible Hydroxy apatite (HAp) coatings on metallic substrate by plasma spray techniques have been developed. Long-term credibility of plasma spray HAp coatings has been evaluated in physiological saline by electrochemical measurements. It was found that the corrosion resisitance of SUS316L based HAp/Ti conbined coatings was excellent even after more than 10 weeks long-term immersion. It was shown that postal heat treatment improved both the crystallinity and corrosion resistance of HAp. By lowering cooling rate during heat treatment process, less cracks produced in HAp coating layer, which lead to higher credibility of HAp during immersion in physiological saline. The ICP results showed that the dissolution level of substrate metallic ions was low and HAp coatings produced in this research can be acceptable as biocompatible materials. Also, the concentration of dissolved ions from HAp coatings with postal heat treatment was lower compared to those from samples without postal heat treatment. The adherence of HAp coatings with Ti substrate and other mechanical properties were also assessed by three-point bending test. The poor adhesion of HAp coating to titanium substrate can be improved by introducing a plasma spray titanium intermediate layer.

WEAR PROPERTY OF PLASMA-SPRAYED COATING LAYERA IN Cr$_2$O$_3$

  • Pakr, J.M.;Lee, S.W.;Kim, Byong-Kee;Lee, Dong-Won
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.745-752
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    • 1996
  • Wear property of plasma spray coating in $Cr_2O_3$ powder manufatured of spray dry method on the aluminum substrate was inspected for the application of piston-ring of automotive enginel. The plama spray coatings were varied with feed rate and particle size. Used the ball-on disc type tribometer, wear volume, friction, surface rougness were investigated. The delamination of the coating layer were observed with SEM. Also the cross-section of wear track were investigated, using optical microscopy. As a result of experiment, wear mechanism was addressed in the various coating process.

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Interaction study of molten uranium with multilayer SiC/Y2O3 and Mo/Y2O3 coated graphite

  • S.K. Sharma;M.T. Saify;Sanjib Majumdar;Palash K. Mollick
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1855-1862
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    • 2023
  • Graphite crucibles are used for melting uranium and its alloys in VIM furnace. Various coating materials namely Al2O3, ZrO2, MgO etc. are applied on the inner surface of the crucibles using paint brush or thermal spray technique to mitigate U-C interaction. These leads to significant amount of carbon pick-up in uranium. In this study, the attempts are made to develop multilayer coatings comprising of SiC/Y2O3 and Mo/Y2O3 on graphite to study the feasibility of minimizing U-C interaction. The parameters are optimized to prepare SiC coating of about 70㎛ thickness using CVD technique on graphite coupons and subsequently Y2O3 coating of about 250㎛ thickness using plasma spray technique. Molybdenum and Y2O3 layers were deposited using plasma spray technique with 70㎛ and 250㎛ thickness, respectively. Interaction studies of the coated graphite with molten uranium at 1450℃ for 20 min revealed that Y2O3 coating with SiC interlayer provides physical barrier for uranium-graphite interaction, however, this led to the physical separation of coating layer. Y2O3 coating with Mo interlayer provided superior barrier effect showing no degradation and the coatings remained intact after interaction tests. Therefore, the Mo/Y2O3 coating was found to be a promising solution for minimizing carbon pick-up during uranium/uranium alloy melting.

Property Analysis of Ceramic Interconnect Prepared by Thermal Plasma Spray Coating Method for SOFC (Thermal Plasma Spray Coating 법에 의해 코팅된 SOFC용 세라믹 연결재 특성 분석)

  • Park, Kwang-Yeon;Pi, Seuk-Hoon;Lee, Jong-Won;Lee, Seung-Bok;Lim, Tak-Hyoung;Park, Seok-Joo;Song, Rak-Hyun;Shin, Dong-Ryul
    • Korean Chemical Engineering Research
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    • v.49 no.6
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    • pp.710-714
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    • 2011
  • In present work, $La_{0.8}Ca_{0.2}CrO_{3}$(LCC), $La_{0.8}Sr_{0.2}CrO_{3}$(LSC) and $La_{0.8}Ca_{0.2}CrO_{0.9}Co_{0.1}O_{3}$(LCCC) ceramic interconnect layer for SOFC were prepared by using thermal plasma spray coating process. The LCC, LSC and LCCC powders were characterized by x-ray diffraction(XRD), scanning electron microscopy(SEM), particle counter and BET analysis. In addition, basic and essential properties such as the surface morphology, cross section, gas leak rate, and electrical conductivity of LCC, LSC, and LCCC layers coated by thermal plasma spray coating process were analyzed and discussed. Based on these experimental results, it can be concluded that the LCCC layer coated by thermal plasma spray coating process can be suitable as a ceramic interconnect of SOFC.

Wear Characteristics of $Cr_{2}O_{3}\;and\;ZrO_{2}$Coating Materials by Plasma Spray ($Cr_2O_3$$ZrO_{2}$ 플라즈마 용사한 코팅재의 마모 특성)

  • Kim, Sung-Ig;Kim, Hee-Gon;Lee, Bong-Gil;Kim, Gui-Shik
    • Tribology and Lubricants
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    • v.22 no.6
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    • pp.335-341
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    • 2006
  • This paper reports the wear characteristics of two types of coating materials, which are $Cr_2O_3$ and $ZrO_2$, by coated plasma thermal spray method. The wear test was carried out under air, grease, and bearing fluid conditions. The wear testing machine of a pin-on disk type were used to measure friction forces, friction coefficients and the weight losses of the coating specimens on the various sliding velocity and loading condition. The wear surface of specimens were observed by scanning electron microscope (SEM) photographs.

Manufacturing and Properties of Low Vacuum Plasma Sprayed W-Carbide Hybrid Coating Layer (진공 플라즈마 스프레이 공정을 이용한 W계 복합 코팅층의 제조 및 특성 연구)

  • Cho, Jin-Hyeon;Jin, Young-Min;Ahn, Jee-Hoon;Lee, Kee-Ahn
    • Journal of Powder Materials
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    • v.18 no.3
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    • pp.226-237
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    • 2011
  • W-ZrC and W-HfC composite powders were fabricated by the Plasma Alloying & Spheroidization (PAS) method and the powders were sprayed into hybrid coating layers by using Low Vacuum Plasma Spray (LVPS) process, respectively. Microstructure, mechanical properties, and ablation characteristics of the fabricated coating layers were investigated. The LVPS process led to successful production of W-Carbide hybrid coatings, approximately 400 ${\mu}M$ or above in thickness. As the substrate preheating temperature increased from $870^{\circ}C$ to $917^{\circ}C$, the hardness of the W-ZrC coating layer increased due to decreased porosity. Vickers hardness showed higher value (about 108.4 HV) in W-ZrC hybrid coating material compared to that of W-HfC while adhesive strength was found to be similar in both coating layers. The plasma torch test revealed good ablation resistance of the W-Carbide hybrid coating layers. The relatively high performance W-ZrC coating layer at the elevated temperature is thought to be attributed to both the strengthening effect of ZrC particle remained in the layer and the formation of ZrO2 phase with high temperature stability.

Study of the thermal shock resistance of multi-coating for C/C composite by plasma spray coating (플라즈마 용사법에 의해 다층코팅된 탄소탄소복합재료의 열충격 저항성 연구)

  • Lee, Gu-Hyeon;Jeong, Seong-Il;Byeon, Eung-Seon;Nam, Gi-Seok
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2013.05a
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    • pp.106-106
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    • 2013
  • C/C Composite는 비교적 낮은 온도에서 산화되어 고유의 특성을 쉽게 잃어버리게 된다. 본 연구에서는 Plasma Spray 코팅방법을 사용하여 다층 코팅층을 형성 시킨 후 $1600^{\circ}C$의 온도에서 열충격 저항성을 평가하였다.

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Fabrication and characteristics of suspension-plasma-sprayed yttrium oxide coatings (서스펜션 플라즈마 스프레이 코팅법을 이용한 이트리아 코팅막 제조와 특성)

  • Kim, Min Suk;So, Sung Min;Kim, Hyung Soon;Park, Seong Hwan;Ham, Young Jae;Jeon, Min Seok;Kim, Kyoung Hun
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.6
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    • pp.359-364
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    • 2019
  • The suspension plasma spraying is a modification of conventional plasma spray techniques that has been developed to overcome the challenge of using fine particles in plasma spray processes. In this study, microstructure developments and mechanical property of yttrium oxide (Y2O3) coatings prepared by the suspension plasma spray coating technique have been investigated to determine the effect of processing parameters including plasma gun current and total gas flow. The results showed that a highly dense Y2O3 coating having low porosity of 0.2 vol% without any lamellar structures can be achieved at the optimum condition of gun current 200 A and total gas flow 220 L/min.