Plasma Spheroidized Alumina/Zircon Mixtures

2000 ◽  
Author(s):  
Y. Li ◽  
K.A. Khor
Keyword(s):  
Thermal Spraying ◽  
Processing Parameters ◽  
High Energy ◽  
Molten State ◽  
Composite Powders ◽  
Spray Process ◽  
Plasma Spheroidization ◽  
Plasma Spray Process ◽  
Energy Ball ◽  
Spheroidized Powder

Abstract The plasma-spray process is specified by the associated processing parameters, where these influence the properties of the resultant deposits. This article describes the preparation and processing of composite powders for use in thermal spraying by mixing high purity zircon and alumina powders. The spheroidized powder were obtained by high energy ball milling and rapid solidification from the molten state during plasma spraying. The article discusses the processes involved in spray drying and plasma spheroidization, describing thermal analysis and mullitization kinetics in the spheroidized alumina/zircon mixtures.

Physical and Electrochemical Properties of SiOx /C Composites Prepared by a Combination of Spray Pyrolysis and High Energy Ball Milling

2015 ◽  
Vol 1775 ◽  
pp. 7-12 ◽  
Author(s):  
Anara Molkenova ◽  
Izumi Taniguchi
Keyword(s):  
Electrochemical Properties ◽  
Spray Pyrolysis ◽  
Ball Milling ◽  
Ultrasonic Spray Pyrolysis ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Potential Range ◽  
Composite Powders ◽  
Ultrasonic Spray ◽  
Energy Ball

ABSTRACTSpray pyrolysis has been widely used to prepare homogeneous and uniform ceramic powders with high purity. In this study, we are proposing ultrasonic spray pyrolysis followed by heat treatment to produce SiOx/C composite powders, where sucrose was used as a carbon source. Furthermore, high energy ball milling of the as-prepared powders in the presence of acetylene black was conducted to activate its electrochemical properties by reducing the particle size and improving the functionalization of the SiOx composite particles. SiOx/C nanocomposite finally obtained at a sucrous concentration of 0.1 mol L-1 showed superior electrochemical properties, and the SiOx/C nanocomposite electrode delivered the first discharge and charge capacities of 1252 and 819 mAh g-1, respectively, with an initial columbic efficiency of 65% at a current density of 50 mAh g-1 in the potential range from 0.01 to 3 V versus Li/Li+.

Development of Ni/h-BN Self-Lubricating Composite Powder by High-Energy Ball Milling

2016 ◽  
Vol 869 ◽  
pp. 277-282
Author(s):  
Moisés Luiz Parucker ◽  
César Edil da Costa ◽  
Viviane Lilian Soethe
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Solid Lubricants ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Second Phase ◽  
Average Particle ◽  
Composite Powders ◽  
The Matrix ◽  
Energy Ball

Solid lubricants have had good acceptance when used in problem areas where the conventional lubricants cannot be applied: under extreme temperatures, high charges and in chemically reactive environments. In case of materials manufactured by powder metallurgy, particles of solid lubricants powders can be easily incorporated to the matrix volume at the mixing stage. In operation, this kind of material provides a thin layer of lubricant that prevents direct contact between the surfaces. The present study aimed at incorporating particles of second phase lubricant (h-BN) into a matrix of nickel by high-energy ball milling in order to obtain a self-lubricating composite with homogeneous phase distribution of lubricant in the matrix. Mixtures with 10 vol.% of h-BN varying the milling time of 5, 10, 15 and 20 hours and their relationship ball/powder of 20:1 were performed. The effect of milling time on the morphology and microstructure of the powders was studied by X-ray diffraction, SEM and EDS. The composite powders showed reduction in average particle size with increasing milling time and the milling higher than 5 hours resulted in equiaxial particles and the formation of nickel boride.

Plasma spray process modelling using artificial neural networks: Application to Al2O3-TiO2 (13% by weight) ceramic coating structure

2004 ◽  
Vol 120 ◽  
pp. 363-370
Author(s):  
S. Guessasma ◽  
G. Montavon ◽  
C. Coddet
Keyword(s):  
Thermal Spraying ◽  
Processing Parameters ◽  
Ceramic Coatings ◽  
Physical Models ◽  
Spray Process ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
The Stability ◽  
Experimental Values ◽  
Physical Phenomena

Thermal spraying is a versatile technique of coating manufacturing implementing large variety of materials and processes. The manufacture control is constrained by the understanding of the physical phenomena occurring during the spraying. It is however penalized by the large number of processing parameters (up to 50), their interdependencies, their correlations with the coating attributes and the stability of the process. Numerous statistical, heuristic or physical models intended to response to these constrains, very often partially because considering some aspects of the process. This work aims at considering a more global approach based on a powerful statistical methodology using artificial intelligence. Following this approach, the physical phenomena are encoded in a structure called Artificial Neural Network (ANN). An application of the ANN methodology is discussed in the case of the APS spray process. Some processing parameters categories are related to some coating properties for alumina-titania (13% by weight) ceramic coatings. ANN optimization is presented and discussed. Predicted results show globally a well agreement with the experimental values. Some conclusions point out the advantages of the ANN on the conventional methods, such as the design of experiments, used usually to recognize the controlling factors in a process.

Al/Al2O3 Nanocomposite Produced by ECAP

2013 ◽  
Vol 762 ◽  
pp. 457-464 ◽  
Author(s):  
Riccardo Casati ◽  
Matteo Amadio ◽  
Carlo Alberto Biffi ◽  
David Dellasega ◽  
Ausonio Tuissi ◽  
...  
Keyword(s):  
Ball Milling ◽  
Metal Matrix ◽  
Numerical Models ◽  
High Energy ◽  
Sem Analysis ◽  
High Energy Ball Milling ◽  
Composite Powders ◽  
Metal Matrix Nanocomposites ◽  
Angular Pressing ◽  
Energy Ball

Metal matrix nanocomposites have been produced by powder metallurgy route. Al and nanoAl2O3powders were grinded through high energy ball milling. Then, the composite powders were sintered by Equal Channel Angular Pressing (ECAP). 12 ECAP passes were carried out in order to improve the dispersion of the hard particles. SEM analysis was performed to investigate the distribution of the ceramic nanoparticles within the matrix. Hardness tests were executed to evaluate the mechanical behavior of the nanocomposites. Finally, mechanical strength values obtained by numerical models were compared with those estimated from hardness measurements. High energy ball milling followed by ECAP process revealed to be a suitable route for the production of metal matrix composites reinforced with well dispersed nanoparticles.

Preparation of C/Cu Composite Powders by High-Energy Ball-Milling

2011 ◽  
Vol 319-320 ◽  
pp. 61-63 ◽  
Author(s):  
Xiu Yan Guo ◽  
Guo Jin Ma ◽  
Shi Kun Xie ◽  
Rong Xi Yi ◽  
Zhi Gao
Keyword(s):  
Ball Milling ◽  
Graphite Powder ◽  
High Energy ◽  
Lattice Parameter ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Mixed Powder ◽  
X Ray ◽  
Energy Ball

Cu-4% mixed-powder consisting of rough copper powder and graphite powder was separately mechanical alloyed by high-energy ball milling. The phases and micrograph of these powders were determined by X-ray diffraction and scanning electron microscopy (SEM). The results show an increase in the lattice parameter of copper with milling times, up to a saturation value of about 24h; There was an absence of graphite reflections from X-ray diffractograms after longer milling times.

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