On The Fabrication and Properties of a Ceramic Cladded Aluminium Powder Using the Spray Drying Process

1998 ◽  
Author(s):  
B. Comas ◽  
C. Mateus ◽  
B. Hansz ◽  
C. Coddet
Keyword(s):  
Spray Drying ◽  
Composite Coatings ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Drying Process ◽  
Manufacturing Method ◽  
Aluminium Powder ◽  
New Family ◽  
Spray Dried ◽  
Scanning Electron

Abstract A new family of spherical powders produced by the spray drying route has been developed. This paper describes as an example the manufacturing method of an Y203-coated aluminum powder. Atmospheric Plasma Spraying (APS) was used to test the corresponding coatings. Morphology and phases of powders and coatings were investigated by optical and scanning electron microscopy while the level of porosity was evaluated using image analysis. Results show that homogenous composite coatings can be obtained from cladded spray dried powders.

scholarly journals Atmospheric Plasma Spraying (APS) and Alloying as Methods to Modify Properties of the SSS Surface Layers

2020 ◽  
Vol 22 (4) ◽  
pp. 80-89
Author(s):  
Barbara Lisiecka ◽  
Agata Dudek ◽  
Robert Ulewicz
Keyword(s):  
Automotive Industry ◽  
Stainless Steels ◽  
Arc Welding ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Surface Layers ◽  
X Ray ◽  
Gas Tungsten Arc ◽  
Roughness Measurements ◽  
Scanning Electron

Use of the powder metallurgy (PM) in production of various components has been growing in the automotive industry, including production of sintered stainless steels (SSSs). This study aims to improve the functional properties of SSSs by formation of the Cr3C2-NiCr coating by APS method. The next stage involved alloying of the surface of SSSs using the gas tungsten arc welding (GTAW). Analysis of microstructures was carried out using microscopy (metallographic microscope and scanning electron microscope). Furthermore, the study presents XRD (X-ray powder diffraction) examinations, mechanical properties and surface roughness measurements. The presented modification improved properties of the surface layers examined in the study and enabled a reduction in the wall thickness of the detail, which is important factor in the automotive and transport industry.

scholarly journals Freeze versus Spray Drying for Dry Wild Thyme (Thymus serpyllum L.) Extract Formulations: The Impact of Gelatin as a Coating Material

2021 ◽  
Author(s):  
Aleksandra A. Jovanović ◽  
Steva M. Lević ◽  
Vladimir B. Pavlovic ◽  
Smilja B. Markovic ◽  
Rada V. Pjanovic ◽  
...  
Keyword(s):  
Spray Drying ◽  
Dry Weight ◽  
Drying Process ◽  
Scanning Calorimetry ◽  
Coating Agent ◽  
Microwave Assisted ◽  
Freeze Dried ◽  
Wild Thyme ◽  
The Impact ◽  
Spray Dried

Freeze drying was compared with spray drying regarding feasibility to process wild thyme drug in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration, heat-, ultrasound-, and microwave-assisted extractions. Higher powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% w/w) provided better TPC recovery by 70% in case of lyophilization and higher powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53-75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation distinguished from others by higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process affected mainly position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray dried formulations compared to freeze dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151-223 µm) compared to small microspheres (~8 µm) in spray-dried powder.

Preparation of PS@SiO2, PS@TiO2，PS@TiO2/SiO2 Core-Shell Composites by a Spray Drying Process and Their Hollow Spheres after Removing PS Cores by Calcinations

2011 ◽  
Vol 194-196 ◽  
pp. 389-392
Author(s):  
Ling Li ◽  
Hong Liang Li ◽  
Ying Chun Zhu ◽  
Ai Ping Fu ◽  
Yong Wan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Spray Drying ◽  
Hollow Spheres ◽  
Nitrogen Adsorption ◽  
Core Shell ◽  
Drying Process ◽  
The Core ◽  
Adsorption Desorption ◽  
Drying Chamber ◽  
Scanning Electron

Polystyrene (PS) spheres encapsulated core-shell composites of SiO2or TiO2nanoparticles were prepared by the spray drying technique and hollow spheres of SiO2or TiO2nanoparticles were then derived by removing the PS cores with calcinations. The PS spheres were dispersed into the SiO2or TiO2colloids, forming a suspension and then the suspensions were sprayed to form micrometer-sized droplets, as the droplets rush through the drying chamber, the PS spheres were encapsulated into the core of SiO2or TiO2particles due to the high temperatures and the instant evaporation, obtaining PS@SiO2, PS@TiO2or PS@SiO2/TiO2core-shell composites. After removing the PS core by calcination at 550°C, SiO2or TiO2hollow spheres were then derived. The influence of drying temperature, the concentration of the SiO2or TiO2particles and the ratio of PS sphere to the particles on the structures and specific surface area of the hollow spheres were studied with scanning electron microscopy (SEM) and nitrogen adsorption-desorption measurements.

scholarly journals Preparation of BaZrO3 powders by a spray-drying process

2003 ◽  
Vol 18 (6) ◽  
pp. 1325-1332 ◽  
Author(s):  
B. Robertz ◽  
F. Boschini ◽  
A. Rulmont ◽  
R. Cloots ◽  
I. Vandriessche ◽  
...  
Keyword(s):  
Spray Drying ◽  
Precursor Solution ◽  
Barium Zirconate ◽  
Drying Process ◽  
X Ray Diffraction ◽  
High Quality ◽  
Corrosion Resistant ◽  
X Ray ◽  
Potential Use ◽  
Scanning Electron

The potential use of barium zirconate for the manufacture of corrosion-resistant substrates emphasizes the need for a simple, inexpensive, and easily scalable process to produce high-quality powders with well-controlled composition and properties. However, the classical solid-state preparation of barium zirconate leads to an inhomogeneous powder unsuitable for applications in highly corrosive environment. For this paper, the possibility to use the spray-drying technique for the preparation of BaZrO3 powders with a controlled size distribution and morphology was investigated. The influence of the nature and concentration of the precursor solution and the influence of the spray-drying step are discussed on the basis of x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dilatometric measurements.

Preparation of Al/SiC Composite Coatings on Surface of Aluminum Alloy by Atmospheric Plasma Spraying

2015 ◽  
Vol 44 (10) ◽  
pp. 2396-2400 ◽  
Author(s):  
Gao Peihu ◽  
Li Jianping ◽  
Yang Zhong ◽  
Guo Yongchun ◽  
Wang Yanrong
Keyword(s):  
Aluminum Alloy ◽  
Plasma Spraying ◽  
Composite Coatings ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma

scholarly journals Formulation and Evaluation of Chitosan/NaCl/Maltodextrin Microparticles as a Saltiness Enhancer: Study on the Optimization of Excipients for the Spray-Drying Process

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4302
Author(s):  
Shang-Ta Wang ◽  
Yi-Ying Lu ◽  
Min-Lang Tsai
Keyword(s):  
Spray Drying ◽  
Moisture Absorption ◽  
Sodium Intake ◽  
Particle Sizes ◽  
Drying Process ◽  
High Moisture ◽  
Waxy Starch ◽  
Dry Food ◽  
And Storage ◽  
Spray Dried

Spray-dried chitosan/NaCl/maltodextrin microparticles have the potential to be used to enhance saltiness; however, its notable hygroscopicity results in handling and storage problems, thus limiting its application. In the present study, we attempted to introduce maltodextrin, microcrystalline cellulose (MCC), and waxy starch (WS) as excipients into the spray drying formulation of microparticles to reduce the cohesiveness and caking behavior and improve the yield simultaneously by ameliorating the moisture absorption tendency. The prepared microparticles showed a spherical appearance and had particle sizes ranging from 6.29 to 7.64 μm, while the sizes of the NaCl crystals embedded in the microparticles were 0.36 to 1.24 μm. The crystalline reflections of WS and MCC were retained in the microparticles after the spray-drying process. The handling properties were assessed to be acceptable. The formulation with only maltodextrin as the excipient showed a high moisture absorption rate of 2.83 g/100 g·h and a caking strength of 3.27 kg. The addition of MCC and WS significantly reduced the hygroscopic rate and caking strength. The spray-dried products provided better saltiness perception than native NaCl; as such, they may be promising for seasoning dry food products to achieve sodium intake reduction in the food industry.

Effects of 316SS addition on the properties of the coatings based on Al2O3 applied by plasma spraying

2018 ◽  
Vol 52 (19) ◽  
pp. 2597-2608
Author(s):  
Amal Chebbi ◽  
Vincent Guipont ◽  
Khaled Elleuch ◽  
Michel Jeandin
Keyword(s):  
Plasma Spraying ◽  
Composite Structures ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Lamellar Microstructure ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Wear Resistant Coatings ◽  
Dense Microstructure ◽  
Carrier Gases

Ceramic plasma-sprayed coatings are successfully used for prolonging the service life of industrial components where high wear and corrosion resistance are required. In this work, various types of coatings based on alumina were deposited by atmospheric plasma spraying on 304 L austenitic stainless steel substrate. These coatings were used in further tribological studies. For the atmospheric plasma spraying applications, spraying parameter choices such as carrier gases, plasma enthalpy, current intensity, spraying distance, and particles granulometry are the key issues. Two kinds of Al2O3 particle sizes 2–12 µm (Amperit) and 15–45 µm (Norton) were used to prepare pure and composite coatings. The spraying distance was varied from 90 mm to 120 mm. Microstructure characterization performed by scanning electron microscopy showed that the Amperit powders projected at a distance of 90 mm provided better cohesion and a more dense microstructure. However, the choice of the spraying distance of 120 mm was defined to manufacture composite structures, which allowed more stability in the plasma jet and enabled large metal particles to be mixed with ceramics. To develop hard and wear-resistant coatings, alumina and 316SS were mixed with different addition rates by volume (Al2O3–5 vol.%316SS and Al2O3–25 vol.%316SS) and fed through a single injection port. Composite coatings include porosity and unmolten particles in a lamellar microstructure. The addition of 316SS powder led to the formation of typical layered structure due to the effect of viscosity and different densities of the two particles. These coatings were investigated by different tests to evaluate microhardness, cohesion, and fracture values of such materials. Despite the significant decrease in the microhardness values, the 316SS particle addition demonstrates an improvement in the toughness and crack resistance.

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