Obtaining Nanopowder Ligature Briquettes Ni-(SiC+Si3N4) for Modification of Aluminum Alloys

2016 ◽  
Vol 685 ◽  
pp. 558-562
Author(s):  
Antonina A. Kuzina ◽  
Valentina S. Ruchkina
Keyword(s):  
Particle Size ◽  
Nickel Powder ◽  
Distribution Density ◽  
Hydraulic Press ◽  
Planetary Mill ◽  
Powder Particle Size ◽  
Technological Properties ◽  
Mechanical Mixing ◽  
Powder Mixtures ◽  
Bulk Weight

The authors investigated the mechanical mixing and compacting briquettes of nickel powder (particle size 30...75 μm) and nanopowder modifier SiC+Si3N4 (particle size 70...100 nanometers), obtained by the azide technology SHS. The mixtures containing 5%, 10%, 15%, 20% of the modifier were investigated. Mechanical mixing was carried out during 60 minutes in planetary mill «Pulverizette-5». Some physic-technological properties of the obtained powder mixtures, such as, particle size distribution, density, bulk weight and flowability, are determined. The powder compositions' pressing was carried out on hydraulic press PSU-50 with pressure 65...700 MPa. Nanopowder ligature briquettes of 18.2 mm diameter, height to 4.2 mm, weighing 5 grams, with relative density 70...89% and porosity 11...30%, intended for subsequent input in aluminum melt with the aim of modification are obtained.

Obtaining Nanopowder Pseudo-Ligatures Al-(SiC+Si3N4) for Modification of Aluminum Alloys

2016 ◽  
Vol 684 ◽  
pp. 310-315
Author(s):  
Antonina A. Kuzina ◽  
Anna V. Kuts
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Distribution Density ◽  
Hydraulic Press ◽  
Planetary Mill ◽  
Powder Particle Size ◽  
Technological Properties ◽  
Mechanical Mixing ◽  
Powder Mixtures ◽  
Bulk Weight

It was investigated the mechanical mixing and compacting briquettes of aluminum powder (particle size 75...250 μm) and nanopowder modifier SiC+Si3N4 (particle size 70...100 nanometers), obtained by the azide technology SHS. The mixtures containing 2.5%, 5%, 10%, 15% of the modifier were investigated. Mechanical mixing was carried out during 60 minutes in planetary mill «Pulverizette-5». Some physic-technological properties of the obtained powder mixtures, such as, particle size distribution, density, bulk weight and flowability, are determined. The powder compositions pressing was carried out on hydraulic press PSU-50 with pressure 25...90 MPa. Nanopowder pseudo-ligatures of 18 mm diameter, height to 4.6 mm, weighing 2.5 grams, with relative density 77...93%, intended for subsequent input in aluminum melt with the aim of modification are obtained.

scholarly journals Effect of Particle Size Distribution on Powder Packing and Sintering in Binder Jetting Additive Manufacturing of Metals

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Yun Bai ◽  
Grady Wagner ◽  
Christopher B. Williams
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Large Degree ◽  
Full Density ◽  
Powder Particle Size ◽  
Powder Mixtures ◽  
Fine Powders ◽  
Sintering Shrinkage ◽  
The Impact ◽  
Binder Jetting

The binder jetting additive manufacturing (AM) process provides an economical and scalable means of fabricating complex parts from a wide variety of materials. While it is often used to fabricate metal parts, it is typically challenging to fabricate full density parts without large degree of sintering shrinkage. This can be attributed to the inherently low green density and the constraint on powder particle size imposed by challenges in recoating fine powders. To address this issue, the authors explored the use of bimodal powder mixtures in the context of binder jetting of copper. A variety of bimodal powder mixtures of various particle diameters and mixing ratios were printed and sintered to study the impact of bimodal mixtures on the parts' density and shrinkage. It was discovered that, compared to parts printed with monosized fine powders, the use of bimodal powder mixtures improves the powder's packing density (8.2%) and flowability (10.5%), and increases the sintered density (4.0%) while also reducing the sintering shrinkage (6.4%).

Behavior of Microwave Heating of 316 Stainless Steel Green Body

2014 ◽  
Vol 936 ◽  
pp. 1694-1700
Author(s):  
Zhi Wei Li ◽  
Kai Yong Jiang ◽  
Fei Wang ◽  
Ji Liang Zhang
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Microwave Heating ◽  
Powder Particle ◽  
Microwave Power ◽  
Arc Discharge ◽  
Steel Powder ◽  
Powder Particle Size ◽  
Auxiliary Heating ◽  
316 Stainless Steel

This paper mainly introduces the mechanism of microwave heating: electric conduction loss, eddy current loss and arc discharge. The microwave heating behavior of 316 stainless steel powder body which made by gel casting was investigated in the paper. Experiments on different microwave power, powder particle size, and the content of auxiliary heating material showed that the smaller the powder particle size, the larger microwave power and auxiliary heating materials help 316 stainless steel body for sintering.

Fabrication of Nanostructured Fe-Co Alloy Powders by Hydrogen Reduction and Its Magnetic Properties

2007 ◽  
Vol 534-536 ◽  
pp. 1389-1392
Author(s):  
Young Jung Lee ◽  
Baek Hee Lee ◽  
Gil Su Kim ◽  
Kyu Hwan Lee ◽  
Young Do Kim
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Grain Size ◽  
Magnetic Properties ◽  
Nanostructured Materials ◽  
Hydrogen Reduction ◽  
Internal Strain ◽  
Oxide Powder ◽  
Powder Mixtures ◽  
Effect Of Microstructure

Magnetic properties of nanostructured materials are affected by the microstructures such as grain size (or particle size), internal strain and crystal structure. Thus, it is necessary to study the synthesis of nanostructured materials to make significant improvements in their magnetic properties. In this study, nanostructured Fe-20at.%Co and Fe-50at.%Co alloy powders were prepared by hydrogen reduction from the two oxide powder mixtures, Fe2O3 and Co3O4. Furthermore, the effect of microstructure on the magnetic properties of hydrogen reduced Fe-Co alloy powders was examined using XRD, SEM, TEM, and VSM.

Tape Casting of BaTiO3

1984 ◽  
Vol 40 ◽  
Author(s):  
J. B. Blum ◽  
W. R. Cannon
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Glass Plate ◽  
Tape Casting ◽  
Phosphate Ester ◽  
Powder Particle Size ◽  
Drying Method ◽  
Ultrasonic Dispersion ◽  
The Past

AbstractFor the past two years we have been investigating the tape casting of BaTiO3 Specifically we have been interested in developing a useful tape casting formulation and procedure and in studying the effects of powder particle size distribution and dispersion processes on the forming of BaTiO3 tapes.The formulation we have developed is non-aqueous. An MEKethanol mixture is the solvent and an acrylic binder is used. Two dispersants are being used, a phosphate ester and Menhaden fish oil. Ultrasonic dispersion was found to be effective in breaking up weak powder agglomerates. We have found it important to add the dispersant before adding other organic components to obtain the best dispersion and strongest tapes. The drying method is also important to tape strength. The strongest tapes resulted when the tape was removed from the glass plate soon after casting. We have also demonstrated that for forming purposes a wide particle size distribution is preferred.

Improvement in Precision, Accuracy, and Efficiency in Standardizing the Characterization of Granular Materials

2013 ◽  
Author(s):  
J. R. Tucker ◽  
L. J. Shadle ◽  
S. Benyahia ◽  
J. Mei ◽  
C. Guenther ◽  
...  
Keyword(s):  
Particle Size ◽  
Distribution Density ◽  
Particle Density ◽  
Solid Particles ◽  
Minimum Fluidization Velocity ◽  
Void Fractions ◽  
Multiphase Systems ◽  
Precision And Accuracy ◽  
Accuracy And Repeatability

Useful prediction of the kinematics, dynamics, and chemistry of a system relies on precision and accuracy in the quantification of component properties, operating mechanisms, and collected data. In an attempt to emphasize, rather than gloss over, the benefit of proper characterization to fundamental investigations of multiphase systems incorporating solid particles, a set of procedures were developed and implemented for the purpose of providing a revised methodology having the desirable attributes of reduced uncertainty, expanded relevance and detail, and higher throughput. Better, faster, cheaper characterization of multiphase systems result. Methodologies are presented to characterize particle size, shape, size distribution, density (particle, skeletal and bulk), minimum fluidization velocity, void fraction, particle porosity, and assignment within the Geldart Classification. A novel form of the Ergun equation was used to determine the bulk void fractions and particle density. Accuracy of properties-characterization methodology was validated on materials of known properties prior to testing materials of unknown properties. Several of the standard present-day techniques were scrutinized and improved upon where appropriate. Validity, accuracy, and repeatability were assessed for the procedures presented and deemed higher than present-day techniques. A database of over seventy materials has been developed to assist in model validation efforts and future designs.

scholarly journals Effect of Home Grinding on Properties of Brewed Coffee

2014 ◽  
Vol 4 (1) ◽  
pp. 77
Author(s):  
Christopher Murray ◽  
Thamara Laredo
Keyword(s):  
Particle Size ◽  
Fourier Transform ◽  
Distribution Density ◽  
Particle Surface ◽  
Particle Surface Area ◽  
Present Evidence ◽  
Caffeine Content ◽  
General Recommendation ◽  
Grinding Time ◽  
Ground Coffee

<p>We present measurements of particle size distribution, density, loss of coffee on brewing and caffeine content in brewed coffee (as measured using Fourier Transform Infrared Spectroscopy) as a function of grinding time using a blade-type grinder. In general, there is not a lack of correlation between coffee properties and grinding for grinding times in excess of 42 s, but mass loss on brewing and caffeine content are both increased with grinding times between 0 and 42 s. In addition, we present evidence that this dependence of the composition of brewed coffee on grinding time is a function of increased coffee particle surface area that results from grinding, rather than increased loss of grounds into the brewed beverage or increased percolation time. Finally, we present a general recommendation for determining equivalency between small amounts of finely ground coffee and larger amounts of coarser-ground coffee.</p>

scholarly journals THE STUDY OF LOW-LACTOSE MILK WHEY STRUCTURE AND MODEL SYSTEMS ON ITS BASIS

2020 ◽  
Vol 3 ◽  
pp. 38-48
Author(s):  
Victoriya Gnitsevych ◽  
Tatiana Yudina ◽  
Yuliia Honchar ◽  
Olena Vasylieva ◽  
Liudmyla Diachuk
Keyword(s):  
Particle Size ◽  
Fractional Composition ◽  
Raw Materials ◽  
Model System ◽  
Model Systems ◽  
Equivalent Diameter ◽  
Contact Method ◽  
Technological Properties ◽  
Milk Whey ◽  
Crystal Diameter

This study developed a technology of low-lactose semi-finished products, based on fermented whey and pumpkin pulp puree, and offered a possibility of its use in the technology of structured culinary products. This research carried out the required substantiation of the methods of preliminary processing of raw materials, and studied the technological properties and structure of model compositions with their use. During the experiment, a number of studies were carried out, which substantiated the method and modes of condensation of whey, and provided a comparative analysis of the homogeneity of lactose-free and lactose-containing samples of whey under various modes of condensation. The study obtained the results of calculations of the equivalent diameter of the studied samples of lactose-containing and low-lactose whey, condensed by the contact method and in vacuum. It was found, that the structure is homogeneous at a number average crystal diameter of up to 5 μm. The restriction is valid for CLLWV with a calculated diameter of about 3.84 μm with a coefficient of variation of 1.35 % with an increase of 10,000 times. The study revealed the alternation of smooth and granular sections of the micron level (0.1 ... 5 μm) in the structure of the studied low-lactose semi-finished product with an increase of 300 times. It was determined, that the extremum of the differential curve of the particle size distribution of CLLWV corresponds to the number average crystal diameter of 3.84 μm. It was established, that the most homogeneous fractional composition is inherent in the studied sample of CLLWV, for which the values of fraction diameters are in the range from 1.46 μm to 4.96 μm. The optimal ratio of the components of the model CLLWV: FPPP system was determined as 70 % to 30 % respectively. With this composition, the model system is characterized by the formation of protein-pectin complexes, which is confirmed by microscopy with a magnification of 90 times

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