scholarly journals Experimental study of tungsten and tungsten alloy coating produced by cold gas dynamic spray and tungsten particles calculation and simulation

2012 ◽  
Vol 61 (2) ◽  
pp. 020207
Author(s):  
Zhang Xiao-Feng ◽  
Ge Chang-Chun ◽  
Li Yu-Jie ◽  
Guo Shuang-Quan ◽  
Liu Wei-Liang
Keyword(s):  
Experimental Study ◽  
Alloy Coating ◽  
Tungsten Alloy ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
And Tungsten ◽  
Cold Gas

Thin Film Coatings of WO3 by Cold Gas Dynamic Spray: A Technical Note

2005 ◽  
Vol 14 (2) ◽  
pp. 183-186 ◽  
Author(s):  
Ha Yong Lee ◽  
Young Ho Yu ◽  
Young Cheol Lee ◽  
Young Pyo Hong ◽  
Kyung Hyun Ko
Keyword(s):  
Thin Film ◽  
Technical Note ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Cold Gas

Combination of electroforming and cold gas dynamic spray for fabrication of rotational moulds: feasibility study

2014 ◽  
Vol 76 (5-8) ◽  
pp. 1243-1251 ◽  
Author(s):  
Fernando Ortega ◽  
Alexey Sova ◽  
Mario D. Monzón ◽  
María D. Marrero ◽  
Antonio N. Benítez ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Cold Gas

Material Properties of Thick Aluminum Coating Made by Cold Gas Dynamic Spray Deposition

2007 ◽  
Vol 345-346 ◽  
pp. 1097-1100
Author(s):  
Jae Chul Lee ◽  
Doo Man Chun ◽  
Sung Hoon Ahn ◽  
Caroline S. Lee
Keyword(s):  
Electrical Resistivity ◽  
Elastic Modulus ◽  
Cold Spray ◽  
Material Properties ◽  
Gas Dynamic ◽  
Macro Scale ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Scale Deposition ◽  
Cold Gas

Cold gas dynamic spray is a relatively new coating process by which coatings can be produced without significant heating during the process. Cold gas dynamic spray is conducted by powder sprayed using supersonic gas jet, and generally called the kinetic spray or cold spray. Its low process temperature can minimize the thermal stress and also reduce the deformation of the substrate. In this study, thick or macro scale deposition was studied while most researches on cold-spray have focused on micro scale coating. Measured material properties of macro scale deposition layer showed that elastic modulus and hardness were lower and electrical resistivity was higher than those of reference substrate material. The main causes of changed material properties were investigated by FE-SEM (Field Emission Scanning Electron Microscope) and EDS (Energy Dispersive X-ray Spectrometer) data. In this result, porous micro structure generated by imperfect plastic deformation might cause decrease in elastic modulus and hardness of the deposition layer by cold spray, and oxidized Al particles increased the electrical resistivity.

The Effects of the Distance Between Nozzle and Substrate on Cold Gas Dynamic Spray Process

2005 ◽  
Author(s):  
Longjian Li ◽  
Wenzhi Cui ◽  
Qinghua Chen ◽  
Tien-Chien Jen ◽  
Quan Liao
Keyword(s):  
Supersonic Nozzle ◽  
Strong Shock ◽  
Two Phase ◽  
Carrier Gas ◽  
Compression Waves ◽  
Spray Process ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Cold Gas

In this paper, numerical simulations were performed for the gas-particle two phase flow in the cold gas dynamic spray process to investigate the acceleration of micro- and nanoparticles with diameters ranging from 100nm to 50μm. Nitrogen (N2) and Helium (He) were chosen as the carrier gas, respectively. The acceleration of carrier gas to particles in the De-Laval-Type supersonic nozzle was strongly dependent on the characteristics of flow field, as well as the densities and the size of the particles. Two kind of particles Copper (Cu) and Platinum (Pt) were chosen as the spraying materials. The computed results showed that the flow structures of the carrier gas were very different for different gas and different spraying distance, which resulted in consequently different accelerating features. The cone-shape weak shocks (compression waves) occurred at the exit of divergent section, and the bow-shaped strong shock wave was found right before the substrate, which played a resistance role to the particles and prevented the smaller particles from approaching on the substrate.

Optimization of Cold Gas Dynamic Spray Processes by Computational Simulation

2007 ◽  
Author(s):  
Hidemasa Takana ◽  
Kazuhiro Ogawa ◽  
Tetsuo Shoji ◽  
Hideya Nishiyama
Keyword(s):  
Shock Wave ◽  
Electrostatic Force ◽  
Particle Diameter ◽  
Integrated Model ◽  
Viscous Drag ◽  
Spray Process ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Cold Gas

An integrated model of compressible thermofluid, splat formation and coating formation for a cold dynamic spray process has been established. In-flight behavior of nano-micro particles and the interaction between the shock wave and the particles in a supersonic jet flow impinging onto the substrate and further particle acceleration with electrostatic force are clarified in detail by considering viscous drag force, flow acceleration, added mass, gravity, Basset history force, Saffman lift force, Brownian motion, thermophoresis and electrostatic force. The effect of electrostatic acceleration becomes more significant with the decrease in particle diameter even in the presence of unavoidable shock wave. As a result, electrostatic acceleration can broaden the application range of operating particle diameter in a cold gas dynamic spray process to form a robust and activated coating. Finally, based on the integrated model, the coating thickness characteristics in an electrostatic assisted cold dynamic spray process are evaluated.

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