High Velocity Pulsed Plasma Thermal Spray

2000 ◽  
Author(s):  
F.D. Witherspoon ◽  
D.W. Massey ◽  
R.W. Kincaid ◽  
G.C. Whichard ◽  
T.A. Mozhi
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Vacuum Chamber ◽  
Thermal Environment ◽  
Diagnostic System ◽  
Inert Atmosphere ◽  
Pulsed Plasma ◽  
Combustible Gases ◽  
Accelerated Particles

Abstract The quality and durability of coatings produced by virtually all thermal spray techniques could be improved by increasing the velocity with which coating particles impact the substrate. Additionally, better control of the chemical and thermal environment seen by the particles during flight is crucial to the quality of the coating. A high velocity thermal spray device is under development through a BMDO SBIR project which provides significantly higher impact velocity for accelerated particles than is currently available with existing thermal spray devices. This device utilizes a pulsed plasma as the accelerative medium for powders introduced into the barrel. Recent experiments using a Control-Vision diagnostic system showed that the device can accelerate stainless steel and WC-Co powders to velocities ranging from 1500 to 2200 m/s. These high velocities are accomplished without the use of combustible gases, and without the need of a vacuum chamber, while maintaining an inert atmosphere for the particles during acceleration. The high velocities corresponded well to modeling predictions, and these same models suggest that velocities as high as 3000 m/s or higher are possible.

High Velocity Pulsed Plasma Thermal Spray

2002 ◽  
Vol 11 (1) ◽  
pp. 119-128 ◽  
Author(s):  
F.D. Witherspoon ◽  
D.W. Massey ◽  
R.W. Kincaid ◽  
G.C. Whichard ◽  
T.A. Mozhi
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Pulsed Plasma

Optimizing Gas-Assisted FIB Processes: The Importance of Oft-Ignored Secondary Parameters

2004 ◽  
Author(s):  
C. Rue ◽  
S. Herschbein ◽  
C. Scrudato ◽  
L. Fischer ◽  
A. Shore
Keyword(s):  
Focused Ion Beam ◽  
Vacuum Chamber ◽  
Ion Beam ◽  
Memory Capacity ◽  
Metal Films ◽  
Deposited Metal ◽  
Influence Process ◽  
Focused Beams ◽  
Gas Pressures

Abstract The efficiency of Gas-Assisted Etching (GAE) and depositions performed using the Focused Ion Beam (FIB) technique is subject to numerous factors. Besides the wellknown primary parameters recommended by the FIB manufacturer (pixel spacing, dwell time, and gas pressures), certain secondary factors can also have a pronounced effect on the quality of these gas-assisted FIB operations. The position of the gas delivery nozzle during XeF2 mills on silicon is examined and was found to affect both the milling speed and the texture on the floor of the FIB trench. Limitations arising from the memory capacity of the FIB computer can also influence process times and trench quality. Exposing the FIB vacuum chamber to TMCTS during SiO2 depositions is found to temporarily impede the performance of subsequent tungsten depositions, especially following heavy or prolonged TMCTS exposure. A delay period may be required to achieve optimal tungsten depositions following TMCTS use. Finally, the focusing conditions of the ion beam are found to have a significant impact on the resistance of FIB-deposited metal films. This effect is attributed to partial milling of the deposition film due to the intense current density of the collimated ion beam. The resistances of metal depositions performed with intentionally defocused ion beams were found to be lower than those performed with focused beams.

scholarly journals Pengaruh Proses Oksidasi Lapisan Metal Matrix Composite pada Substrat SS316

2019 ◽  
Vol 4 (2) ◽  
pp. 277
Author(s):  
Erie Martides ◽  
Candra Dewi Romadhona ◽  
Djoko Hadi Prajitno ◽  
Budi Prawara
Keyword(s):  
Metal Matrix Composite ◽  
Thermal Spray ◽  
Matrix Composite ◽  
High Velocity ◽  
Metal Matrix ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
High Velocity Oxygen Fuel ◽  
Hvof Thermal Spray ◽  
Oxygen Fuel

Material SS316 seringkali digunakan untuk komponen yang bekerja pada temperatur tinggi dengan resiko mengalami oksidasi yang menyebabkan penurunan sifat material dan umur pakai dari komponen. Deposisi Metal Matrix Composite (MMC) NiCr+Cr3C2+Al2O3 dan NiCr+WC12Co+Al2O3 menggunakan metode High Velocity Oxygen Fuel (HVOF) thermal spray coating dengan parameter konstan dilakukan sebagai proses perlakuan pada permukaan SS316 untuk meningkatkan nilai kekerasan dan ketahanan terhadap oksidasi.  Tujuan penelitian ini adalah untuk mengetahui pengaruh proses oksidasi lapisan MMC pada material substrat SS316. Proses oksidasi dilakukan dengan variasi temperatur 500° dan 600°C, penahanan temperatur selama 6 jam, kemudian diteruskan dengan karakterisasi serta perhitungan laju oksidasi. Hasil penelitian menunjukkan spesimen MMC NiCr+Cr3C2+Al2O3 yang dilakukan proses oksidasi pada suhu 500°C memiliki laju oksidasi terendah yaitu 6,67 x 10-7 gram/mm2 jam. 

scholarly journals Research on the Influence of the Distribution Pattern of Building Clusters in Coastal Areas on Wind Environment -Focused on Busan area in Korea

2021 ◽  
Vol 308 ◽  
pp. 02010
Author(s):  
Yang Huimin ◽  
Zhao Shuwen ◽  
Kim Chulsoo
Keyword(s):  
Thermal Environment ◽  
Simulation Software ◽  
Fluid Simulation ◽  
Wind Environment ◽  
Environment Quality ◽  
Ventilation Efficiency ◽  
Urban Thermal Environment ◽  
The City ◽  
Public Environment

With the development of urbanization, the heat island phenomenon has led to further deterioration of the urban thermal environment, resulting in wind environment differences. To study the thermal environment of the city, this paper takes the Busan area in South Korea as the research object and analyzes the connection between the layout of buildings and the wind environment based on the microscopic wind environment characteristics of the coastal area using CFD air-fluid simulation software and suggests that the monsoon influence brought by the coastal currents should be paid attention to, the layout of wind-oriented building groups should be improved, urban air ducts should be established to enhance the ventilation efficiency, and the wind environment of the urban public environment and buildings should be guaranteed. The wind environment quality of urban public environment and indoor environment should be ensured.

A Splats Obtaining System for Thermal Spray Deposits

2007 ◽  
Vol 561-565 ◽  
pp. 1169-1172 ◽  
Author(s):  
W.T. Hsiao ◽  
W.H. Liao ◽  
M.S. Leu ◽  
Cherng Yuh Su
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Glass Substrate ◽  
Single Spot ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Hvof Process

The image of thermal spray splats is difficult to collect due to its high velocity of droplets. Especial in High Velocity Oxy-Fuel (HVOF) process, the process present higher velocity of flame jet correlated to other thermal spray process. The system presents at this article describes a useful splats catching method to obtaining splats during thermal spray deposited. Capabilities and advantages of using this instrument are declared at this theme. The final result presented the instrument caught the single spot of HVOF sprayed splats at sub-micro second. Splats of spot were dispersed well on the glass substrate at the obtaining system, and presented various information of droplets impact at different location on the substrate.

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