• Title, Summary, Keyword: Plasma Spray

Search Result 315, Processing Time 0.038 seconds

Optimal Condition of Hydroxyapatite Powder Plasma Spray on Ti6Al4V Alloy for Implant Applications

  • Ahn, Hyo-Sok;Lee, Yong-Keun
    • Korean Journal of Materials Research
    • /
    • v.22 no.4
    • /
    • pp.211-214
    • /
    • 2012
  • Optimal conditions for HA plasma spray-coating on Ti6Al4V alloy were investigated in order to obtain enhanced bone-bonding ability with Ti6Al4V alloy. The properties of plasma spray coated film were analyzed by SEM, XRD, surface roughness measurement, and adhesion strength test because the film's transformed phase and crystallinity were known to be influential to bone-bonding ability withTi6Al4V alloy. The films were formed by a plasma spray coating technique with various combinations of plasma power, spray distance, and auxiliary He gas pressure. The film properties were analyzed in order to determine the optimal spray coating parameters with which we will able to achieve enhanced bone-bonding ability with Ti6Al4V alloy. The most influential coating parameter was found to be the plasma spray distance to the specimen from the spray gun nozzle. Additionally, it was observed that a relatively higher film crystallinity can be obtained with lower auxiliary gas pressure. Moderate adhesion strength can be achievable at minimal plasma power. That is, adhesion strength is minimally dependent on the plasma power. The combination of shorter spray distance, lower auxiliary gas pressure, and moderate spray power can be recommended as the optimal spray conditions. In this study, optimal plasma spray coated films were formed with spray distance of 70 mm, plasma current of 800 A, and auxiliary gas pressure of 60 psi.

Study on Corrosion Resistance Performance of Zn Coating Applied by Arc Thermal and Plasma Arc Spray Process in Artificial Ocean Water (인공해양환경에서 Arc Thermal and Plasma Arc Spray 공법이 적용된 Zn 코팅 강재의 내식성능 평가에 관한 연구)

  • Jannat, Adnin Raihana;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • /
    • pp.83-84
    • /
    • 2020
  • In present study, we have deposited the Zinc coating using arc thermal spray and plasma arc spray processes onto the steel substrate and durability of the deposited coating was evaluated. The bond adhesion result shows that plasma arc sprayed Zn coating exhibited higher in its value compared to arc thermal spray. SEM shows that Zn coating deposited by plasma arc process is more compact, less porous and adherent compare to arc spray process. The corrosion resistance properties are evaluated in artificial ocean water solution with exposure periods. EIS results show that total impedance at 0.01 Hz of plasma arc sprayed coating is higher than arc thermal spray owing to the compact and less porous morphology. It is concluded that plasma arc sprayed Zn coating is better than arc thermal spray process.

  • PDF

Fabrication of Agglomerated Cr$_2$O$_3$ Powder for Plasma Spray Coating by Spray Drying Process (분무 건조법에 의한 프라즈마 용사를 Cr$_2$O$_3$조립 분말 제조)

  • 이동원
    • Journal of Korean Powder Metallurgy Institute
    • /
    • v.5 no.1
    • /
    • pp.28-34
    • /
    • 1998
  • Plasma sprayed ceramic coatings are widely used in various industrial fields to improve their properties or to reduce the production cost. The ceramic powders for plasma spray coating have been mainly manufactured by spray drying or fused+crushed process. In this study, chromium oxide which has better mechanical properties than those of the other ceramic was selected and agglomerated chromium oxide powders for plasma spray coating were produced by spray drying process with a various processing condition. The large hollow powders and the harsh surfaced powders are formed at high slurry feed rate more than 163 g/min. and low binder concentration less than 2wt%, respectively. These powders cause the considerable decrease of flowability and apparent density. The powders produced by spray drying process have the spherical shape with the mean size of 45 ${\mu}m$, but these are shown lower apparent density and flowability than the powders produced by fused+crushed powders. The plasma spray coated layers by spray dried powders are shown a different microstructure with that by fused+crushed powders in porosity shape, but their properties such as density, hardness and bond strength are similar.

  • PDF

Acoustic Emission Characteristics of Plasma Sprayed Ceramic Coating Layer after Salt Spray (플라즈마용사 세라믹코팅 피막부식재의 음향방출 특성)

  • 김귀식;박경석;홍용의
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • /
    • pp.344-349
    • /
    • 2001
  • This paper was to investigate of a adhesiveness for the plasma sprayed coating materials did salt spray by acoustic emission method in tensile loadings. The powders used for the coating were nickel aluminum composite powder Ni-4,5wt.%Al and titanium dioxide powder Ti02. These powders were coated on a carbon steel S45C by plasma spray method. The salt solution was a 5% NaCl and the salt spray times were 2, 5 and 10 hours respectively. The salt solution penetrated into the surface of the substrate through pore of the coating layer built in the process of plasma spay. Corrosion productions formed on the surface of substrate. The adhesiveness between the substrate and the coating layer is weaken by corrosion and the exfoliation initiated chiefly at the corrosion surface of the substrate. The AE events and energy of the corroded coating specimens decreased as the salt spray times increased.

  • PDF

Acoustic Emission Characteristics of Plasma Sprayed Ceramic Coating Layer after Salt Spray (플라즈마용사 세라믹코팅 피막부식재의 음향방출 특성)

  • 김귀식;박경석;홍용의
    • Journal of Ocean Engineering and Technology
    • /
    • v.15 no.3
    • /
    • pp.69-74
    • /
    • 2001
  • This paper was to investigate of a adhesiveness for the plasma sprayed coating materials did salt spray by acoustic emission method in tensile loadings. The powders used for the coating were nickel aluminum composite powder Ni-4.5wt.%Al and titanium dioxide powder $TiO_2$. These powders were coated on a carbon steel S45C by plasma spray method. The result solution was a 5% NaCl and the slat spray times were 2, 5 and 10 hours respectively. The salt solution penetrated into the surface of the substrate through pore of the coating layer built in the process of plasma spay. Corrosion productions formed on the surface of substrate. The adhesiveness between the substrate and the coating layer is weaken by corrosion and the exfoliation initiated chiefly at the corrosion surface of the substrate. The AE events and energy of the corroded coating specimens decreased as the salt spray times increased.

  • PDF

The Effects of Spray Conditions on Sliding Wear Characteristics of Plasma Sprayed $Al_2O_3-40%TiO_2$Coating (Plasma용사한 $Al_2O_3-40%TiO_2$의 미끄럼마모특성에 미치는 용사조건의 영향)

  • 이한영;노정균;배상규
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • /
    • pp.80-88
    • /
    • 2000
  • The plasma spray technics has known as one of the surface modification methods to improve the mechenical properties or the functional charactristics of materials. This paper has been aimed to investigate the effects of plasma sprayed conditions, such as spray distance and arc power level, on sliding wear properties of plasma sprayed $Al_2$O$_3$-40%TiO$_2$coating layer. The sliding wear test using pin-on-disc type wear machine, has been conducted in several sliding speed for coating layer sparyed under different conditions. The result of this paper is that the wear resistance of plasma sprayed $Al_2$O$_3$-40%TiO$_2$coating layer is fluctuated with tile spray distance and the arc power level. The wear resiatance could be improved with decreasing the spray distance and with increasing the arc power level.

  • PDF

Microstructural Evolution of Thick Tungsten Deposit Manufactured by Atmospheric Plasma Spray Forming Route (Plasma Spray Forming 공정에 의해 제조된 텅스텐 성형체의 미세조직 형성 거동)

  • Lim, Joo-Hyun;Baik, Kyeong-Ho
    • Journal of Korean Powder Metallurgy Institute
    • /
    • v.16 no.6
    • /
    • pp.403-409
    • /
    • 2009
  • Plasma spray forming is recently explored as a near-net-shape fabrication route for ultra-high temperature metals and ceramics. In this study, monolithic tungsten has been produced using an atmospheric plasma spray forming and subsequent high temperature sintering. The spray-formed tungsten preform from different processing parameters has been evaluated in terms of metallurgical aspects, such as density, oxygen content and hardness. A well-defined lamellae structure was formed in the as-sprayed deposit by spreading of completely molten droplets, with incorporating small amounts of unmelted/partially-melted particles. Plasma sprayed tungsten deposit had 84-87% theoretical density and 0.2-0.3 wt.% oxygen content. Subsequent sintering at 2500$^{\circ}C$ promoted the formation of equiaxed grain structure and the production of dense preform up to 98% theoretical density.

Fabrication, Microstructure and Adhesive Properties of BCuP-5 Filler Metal/Ag Plate Composite by using Plasma Spray Process (Plasma spray 공정을 이용한 BCuP-5 filler 금속/Ag 기판 복합 소재의 제조, 미세조직 및 접합 특성)

  • Youn, Seong-June;Kim, Young-Kyun;Park, Jae-Sung;Park, Joo-Hyun;Lee, Kee-Ahn
    • Journal of Korean Powder Metallurgy Institute
    • /
    • v.27 no.4
    • /
    • pp.333-338
    • /
    • 2020
  • In this study, we fabricate a thin- and dense-BCuP-5 coating layer, one of the switching device multilayers, through a plasma spray process. In addition, the microstructure and macroscopic properties of the coating layer, such as hardness and bond strength, are investigated. Both the initial powder feedstock and plasma-sprayed BCuP-5 coating layer show the main Cu phase, Cu-Ag-Cu3P ternary phases, and Ag phase. This means that microstructural degradation does not occur during plasma spraying. The Vickers hardness of the coating layer was measured as 117.0 HV, indicating that the fine distribution of the three phases enables the excellent mechanical properties of the plasma-sprayed BCuP-5 coating layer. The pull-off strength of the plasma-sprayed BCuP-5 coating layer is measured as 16.5 kg/㎠. Based on the above findings, the applicability of plasma spray for the fabrication process of low-cost multi-layered electronic contact materials is discussed and suggested.

Optimization of the Plasma Spray Coating Parameters of Ni-5%Al Alloy Powder Using the Taguchi Experimental Method (다꾸찌방법에 의한 Ni-5%Al 합금 분말의 플라즈마 용사코팅 조건의 최적화)

  • 이형근
    • Journal of Welding and Joining
    • /
    • v.20 no.5
    • /
    • pp.120-126
    • /
    • 2002
  • Ni-5%Al alloy powder is widely used as the bond coating powder to improve the adhesive strength between the substrate and coating. The important properties in the bond coating are the deposition efficiency and surface roughness. In this study, it was tried to optimize the plasma spray parameters to maximize the deposition efficiency and surface roughness. In the first step, spray current and hydrogen gas flow rate were optimized in order to increase the deposition efficiency. In the next step, the seven plasma spray variables were selected and optimized to improve both the deposition efficiency and surface roughness using the Taguchi experimental method. By these optimization, the deposition efficiency was improved from about 10 % at the frist time to 51.2 % by the optimization of spray current and hydrogen gas flow rate and finally to 65.2 % by the Taguchi experimental method. The average surface roughness was increased from about $12.9\mu\textrm{m}$ to $15.4\mu\textrm{m}$.

Microstructural Evolution of Aluminum Nitride - Yttrium Aluminum Garnet Composite Coatings by Plasma Spraying from Different Feedstock Powders (Aluminum Nitride - Yttrium Aluminum Garnet 분말 특성과 플라즈마 용사 코팅층의 미세조직)

  • So, Woong-Sub;Baik, Kyeong-Ho
    • Korean Journal of Materials Research
    • /
    • v.21 no.2
    • /
    • pp.106-110
    • /
    • 2011
  • A high thermal conductive AlN composite coating is attractive in thermal management applications. In this study, AlN-YAG composite coatings were manufactured by atmospheric plasma spraying from two different powders: spray-dried and plasma-treated. The mixture of both AlN and YAG was first mechanically alloyed and then spray-dried to obtain an agglomerated powder. The spray-dried powder was primarily spherical in shape and composed of an agglomerate of primary particles. The decomposition of AlN was pronounced at elevated temperatures due to the porous nature of the spray-dried powder, and was completely eliminated in nitrogen environment. A highly spherical, dense AlN-YAG composite powder was synthesized by plasma alloying and spheroidization (PAS) in an inert gas environment. The AlN-YAG coatings consisted of irregular-shaped, crystalline AlN particles embedded in amorphous YAG phase, indicating solid deposition of AlN and liquid deposition of YAG. The PAS-processed powder produced a lower-porosity and higher-hardness AlN-YAG coating due to a greater degree of melting in the plasma jet, compared to that of the spray-dried powder. The amorphization of the YAG matrix was evidence of melting degree of feedstock powder in flight because a fully molten YAG droplet formed an amorphous phase during splat quenching.