scholarly journals Development and Characterization of Phosphate-Based Glass Coatings via Suspension High-Velocity Oxy-Fuel (SHVOF) Thermal Spray Process

2021 ◽  
Author(s):  
S. Bano ◽  
A. Rincon Romero ◽  
Md Towhidul Islam ◽  
D. M. Grant ◽  
I. Ahmed ◽  
...  
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Structural Changes ◽  
Physical And Mechanical Properties ◽  
Oxygen Species ◽  
Ion Release ◽  
Thermal Spray Process ◽  
Initial Glass ◽  
Spray Process ◽  
Degradation Rates

AbstractPhosphate-based glasses (PBGs) are promising materials for biomedical applications due to their biocompatible and fully resorbable characteristics in aqueous environments. These glasses can be coated onto metal substrate via the technique of suspension high-velocity oxy-fuel (SHVOF) thermal spraying to produce nanostructured coatings with improved physical and mechanical properties. PBGs coatings were produced using SHVOF thermal spray process at 50 and 75 kW flame power. The 75 kW coating was rougher (Ra = 3.6 ± 0.1 µm) than the 50 kW coating (Ra = 2.7 ± 0.1 µm), whereas the 50 kW coating was much thicker (24.6 ± 2.3 µm) than the 75 kW coating (16.0 ± 3.4 µm). Due to the rougher surface, the 75 kW coating showed high degradation and ion release rates. Moreover, structural changes were observed by Raman analysis, and the initial glass formulation contained Q1 (phosphate tetrahedra with one-bridging oxygen) and Q2 (phosphate tetrahedra with two-bridging oxygen) species. However, the coatings showed a reduction of Q2 species and higher concentrations of Q1 and Q0 (phosphate tetrahedra with no-bridging oxygen) species, which led to lower degradation rates and reduced ion release profiles in the glass coating compared to the initial glass.

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.

Aerodynamic study on supersonic flows in high-velocity oxy-fuel thermal spray process

2005 ◽  
Vol 14 (2) ◽  
pp. 126-129 ◽  
Author(s):  
Hiroshi Katanoda ◽  
Takeshi Matsuoka ◽  
Seiji Kuroda ◽  
Jin Kawakita ◽  
Hirotaka Fukanuma ◽  
...  
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Supersonic Flows ◽  
Thermal Spray Process ◽  
Spray Process

Aluminum and copper deposition through the process of thermal flame spray on polypropylene-pine wood fiber composite filaments and their applications

2021 ◽  
pp. 002199832110365
Author(s):  
Sônia MA Veroneze ◽  
Thais HS Flores-Sahagun ◽  
Ramón SC Paredes ◽  
Kestur Gundappa Satyanarayana
Keyword(s):  
Fiber Composite ◽  
Wood Fiber ◽  
Physical And Mechanical Properties ◽  
Heat Treating ◽  
Flame Spray ◽  
Pine Wood ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Copper Coatings ◽  
Study Results

This paper presents a study about polypropylene-pine wood composites, both as filaments and products, coated with aluminum (Al) or copper (Cu), obtained through flame thermal spray process after subjecting the composites to thermal treatments in the second and third step of the study. Results revealed that a previous aluminum layer was needed in order to obtain copper coatings on the composites. The physical and mechanical properties of both metal coated composite filaments were also evaluated and compared with the uncoated composite filaments with and without heat treating these. Consequently, it was observed that the nature of the coating adhesion on the substrates was mechanical, and therefore abrasion blasting of filaments or the use of a higher wood fiber content in the composite improved the Al or Cu adhesion. Also, it was observed that extruded wood fiber/PP filaments should not be cooled in water because pieces might be molded directly once the moisture affects the metal coatings adhesion onto the substrates.

Lead-Free Piezoelectric Ceramic Coatings Fabricated by Thermal Spray Process

2017 ◽  
Vol 64 (11) ◽  
pp. 1758-1765 ◽  
Author(s):  
Kui Yao ◽  
Shuting Chen ◽  
Kun Guo ◽  
Chee Kiang Ivan Tan ◽  
Meysam Sharifzadeh Mirshekarloo ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Piezoelectric Ceramic ◽  
Ceramic Coatings ◽  
Lead Free ◽  
Thermal Spray Process ◽  
Spray Process

THE EFFECT OF FUEL TO OXYGEN RATIOS ON THE PROPERTIES OF HIGH VELOCITY OXY-FUEL TiO2 NANO-PHOTOCATALYST COATINGS

2010 ◽  
Vol 24 (02) ◽  
pp. 247-255 ◽  
Author(s):  
MARYAMOSSADAT BOZORGTABAR ◽  
MEHDI SALEHI ◽  
MOHAMMADREZA RAHIMIPOUR ◽  
MOHAMMADREZA JAFARPOUR
Keyword(s):  
Electron Microscopy ◽  
Crystallite Size ◽  
High Velocity ◽  
X Ray Diffraction ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Transmission Electron ◽  
Hvof Thermal Spray ◽  
Coating Morphology ◽  
Oxygen Ratio

A liquid fuel high velocity oxy-fuel (HVOF) thermal spray process has been used to deposit TiO 2 photocatalytic coatings utilizing a commercially available anatase/rutile nano-powder as the feedstock. The coatings were characterized in terms of the phases present, its crystallite size and coating morphology by means of X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy, respectively. The results indicate that the sprayed TiO 2 coatings were composed of both TiO 2 phases, namely anatase and rutile with different phase content and crystallite size. A high anatase content of 80% by volume was achieved at 0.00015 fuel to oxygen ratio with nanostructure coating by grain size smaller than feedstock powder. It is found that fuel to oxygen ratio strongly influenced on temperature and velocity of particles in stream jet consequently on phase transformation of anatase to rutile and their crystallite size and by optimizing the ratio which can promote structural transformation and grain coarsening in coating.

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