scholarly journals High Velocity Suspension Flame Spraying (HVSFS) of Metal Suspensions

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 621 ◽  
Author(s):  
Blum ◽  
Krieg ◽  
Killinger ◽  
Gadow ◽  
Luth ◽  
...  
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Thermal Spraying ◽  
Flame Spraying ◽  
Metal Coatings ◽  
Fine Grained ◽  
Aqueous Solvent ◽  
Coating Morphology ◽  
Oxygen Fuel ◽  
Suspension Preparation

Thermal spraying of metal materials is one of the key applications of this technology in industry for over a hundred years. The variety of metal-based feedstocks (powders and wires) used for thermal spray is incredibly large and utilization covers abrasion and corrosion protection, as well as tribological and electrical applications. Spraying metals using suspension- or precursor-based thermal spray methods is a relatively new and unusual approach. This publication deals with three metal types, a NiCr 80/20, copper (Cu), and silver (Ag), sprayed as fine-grained powders dispersed in aqueous solvent. Suspensions were sprayed by means of high-velocity suspension spraying (HVSFS) employing a modified TopGun system. The aim was to prepare thin and dense metal coatings (10–70 µm) and to evaluate the process limits regarding the oxygen content of the coatings. In case of Cu and Ag, possible applications demand high purity with low oxidation of the coating to achieve for instance a high electrical conductivity or catalytic activity. For NiCr however, it was found that coatings with a fine dispersion of oxides can be usable for applications where a tunable resistivity is in demand. The paper describes the suspension preparation and presents results of spray experiments performed on metal substrates. Results are evaluated with respect to the phase composition and the achieved coating morphology. It turns out that the oxidation content and spray efficiency is strongly controlled by the oxygen fuel ratio and spray distance.

Comparison between Tribological Characteristics of Al-Cu-Fe-B Quasicrystalline and Mo Coatings

2007 ◽  
Vol 26-28 ◽  
pp. 715-718
Author(s):  
Bong Hwan Kim ◽  
Sang Mok Lee
Keyword(s):  
Mechanical Properties ◽  
Surface Energy ◽  
Bonding Strength ◽  
Tribological Behavior ◽  
Thermal Spraying ◽  
Microstructural Characterization ◽  
Flame Spraying ◽  
Energy Calculation ◽  
Air Plasma ◽  
Oxygen Fuel

Al-Cu-Fe-B quasicrystalline and Mo coatings were obtained on the mild steel and brass substrates by thermal spraying routes for the purpose of replacement of Mo coatings with quasicrystalline ones. Quasicrystalline coatings were prepared by air plasma spraying and/or HVOF (High Velocity Oxygen Fuel) techniques followed by subsequent heat treatment, and Mo coatings, wire flame spraying. For comparative studies of important properties for industrial application, mechanical properties, bonding strength, surface energy, and tribological behavior were investigated based on microstructural characterization. Basic mechanical properties such as hardness, fracture toughness, and elastic modulus of quasicrystalline coating showed comparable values with those of Mo coatings. De-bonding tests of coatings deposited onto brass substrate indicated that the bonding strength of quasicrystalline coatings obtained by HVOF techniques exhibit higher value to Mo coatings. Non-sticking property analogized from surface energy calculation and friction coefficient of quasicrystalline coatings also showed better performance during the tests. It is suggested from this investigation that the quasicrystalline coating can be effectively used as a replacement of the Mo coating, which has shown a recent steep price rise and problems of accidental existence of minor environment harmful elements such as Cr6+, Pb, Cd, and Hg.

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. 

Design System of High-Velocity Oxygen Fuel (HVOF) Thermal Spray Coating Based on Computerization

2017 ◽  
Vol 728 ◽  
pp. 105-110
Author(s):  
Vita Susanti ◽  
Erie Martides ◽  
Midriem Mirdanies ◽  
Budi Prawara ◽  
Ant. Ardath Kristi ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Mass Flow ◽  
High Velocity ◽  
Combustion Process ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
High Velocity Oxygen Fuel ◽  
Mass Flow Controller ◽  
Flow Controller ◽  
Oxygen Fuel

Wear and corrosion are problems prevalent in the industrialized world. One way to overcome this matter is the process of coating with a thermal spray coating. The coating process is categorized into two processes based on the heat source, i.e., combustion and electric. One example of combustion process is the high-velocity oxygen fuel (HVOF). The HVOF system which is operated manually has been studied in previous works. Computerized HVOF system is developed and manufactured in this study to improve reproducibility of coating and safety of operator. ATMega16 microcontroller was connected with several sensors (oxygen mass flow controller, nitrogen mass flow controller, propane mass flow controller, and pressure sensor), and Visual Studio.Net 2013 was used to create a graphic user interface (GUI). Based on test results obtained, it was found that the GUI successfully communicated using serial communications and could access the input/output (I/O) required by the microcontroller. Combinaton of gas mass flow controller and pressure sensors result in precise control of oxy-fuel combustion process.

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