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%).

Binder Jetting Additive Manufacturing of Ceramics: Feedstock Powder Preparation by Spray Freeze Granulation

2019 ◽  
Author(s):  
Wenchao Du ◽  
Guanxiong Miao ◽  
Lianlian Liu ◽  
Zhijian Pei ◽  
Chao Ma
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Feed Rate ◽  
Freeze Drying ◽  
Granule Size ◽  
Feedstock Powder ◽  
Powder Preparation ◽  
Promising Technology ◽  
Spray Freeze Drying ◽  
Binder Jetting

Abstract Objective of this study is to prepare the binder jetting feedstock powder by spray freeze drying and study the effects of its parameters on the powder properties. Binder jetting additive manufacturing is a promising technology for fabricating ceramic parts with complex or customized geometries. However, this process is limited by the relatively low density of the fabricated parts even after sintering. The main cause comes from the contradicting requirements of the particle size of the feedstock powder: a large particle size (> 5 μm) is required for a high flowability while a small particle size (< 1 μm) for a high sinterability. For the first time, a novel technology for the feedstock material preparation, called spray freeze drying, is investigated to address this contradiction. Using raw alumina nanopowder (100 nm), a full factorial design at two levels for two factors (spraying pressure and slurry feed rate) was formed to study their effects on the properties (i.e., granule size, flowability, and sinterability) of the obtained granulated powder. Results show that high pressure and small feed rate lead to small granule size. Compared with the raw powder, the flowability of the granulated powders was significantly increased, and the high sinterability was also maintained. This study proves that spray freeze granulation is a promising technology for the feedstock powder preparation of binder jetting additive manufacturing.

Ceramic binder jetting additive manufacturing: Effects of particle size on feedstock powder and final part properties

2020 ◽  
Vol 46 (10) ◽  
pp. 16966-16972 ◽  
Author(s):  
Mohammadamin Moghadasi ◽  
Wenchao Du ◽  
Ming Li ◽  
Zhijian Pei ◽  
Chao Ma
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Final Part ◽  
Feedstock Powder ◽  
Ceramic Binder ◽  
Binder Jetting

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.

scholarly journals A Review on Binder Jet Additive Manufacturing of 316L Stainless Steel

2019 ◽  
Vol 3 (3) ◽  
pp. 82 ◽  
Author(s):  
Saereh Mirzababaei ◽  
Somayeh Pasebani
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Processing Parameters ◽  
Parameters Optimization ◽  
Full Density ◽  
Drying Time ◽  
Metallic Parts ◽  
Binder Saturation ◽  
Binder Jetting

Binder jet additive manufacturing enables the production of complex components for numerous applications. Binder jetting is the only powder bed additive manufacturing process that is not fusion-based, thus manufactured parts have no residual stresses as opposed to laser-based additive manufacturing processes. Binder jet technology can be adopted for the production of various small and large metallic parts for specific applications, including in the biomedical and energy sectors, at a lower cost and shorter lead time. One of the most well-known types of stainless steels for various industries is 316L, which has been extensively manufactured using binder jet technology. Binder jet manufactured 316L parts have obtained near full density and, in some cases, similar mechanical properties compared to conventionally manufactured parts. This article introduces methods, principles, and applications of binder jetting of SS 316L. Details of binder jetting processes, including powder characteristics (shape and size), binder properties (binder chemistry and droplet formation mechanism), printing process parameters (such as layer thickness, binder saturation, drying time), and post-processing sintering mechanism and densification processes, are carefully reviewed. Furthermore, critical factors in the selection of feedstock, printing parameters, sintering temperature, time, atmosphere, and heating rate of 316L binder jet manufactured parts are highlighted and summarized. Finally, the above-mentioned processing parameters are correlated with final density and mechanical properties of 316L components to establish a guideline on feedstock selection and process parameters optimization to achieve desired density, structure and properties for various applications.

scholarly journals Structure and Properties of Barium Titanate Lead-Free Piezoceramic Manufactured by Binder Jetting Process

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4419
Author(s):  
Vadim Sufiiarov ◽  
Artem Kantyukov ◽  
Anatoliy Popovich ◽  
Anton Sotov
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Barium Titanate ◽  
Manufacturing Process ◽  
Lead Free ◽  
Density Values ◽  
Binder Saturation ◽  
Binder Jetting ◽  
Titanate Lead ◽  
Functional Ceramics

This article presents the results of manufacturing samples from barium titanate (BaTiO3) lead-free piezoceramics by using the binder jetting additive manufacturing process. An investigation of the manufacturing process steps for two initial powders with different particle size distributions was carried. The influence of the sintering and the particle size distribution of the starting materials on grain size and functional properties was evaluated. Samples from fine unimodal powder compared to coarse multimodal one have 3–4% higher relative density values, as well as a piezoelectric coefficient of 1.55 times higher values (d33 = 183 pC/N and 118 pC/N correspondingly). The influence of binder saturation on sintering modes was demonstrated. Binder jetting with 100% saturation for both powders enables printing samples without delamination and cracking. Sintering at 1400 °C with a dwell time of 6 h forms the highest density samples. The microstructure of sintered samples was characterized with scanning electron microscopy. The possibility of manufacturing parts from functional ceramics using additive manufacturing was demonstrated.

Influence of Parameters on Alumina Particles Size and Morphology

2011 ◽  
Vol 382 ◽  
pp. 336-339
Author(s):  
Qi Zhou ◽  
Hong Liang Zhao ◽  
Zhong Cai Shao ◽  
En Jun Song
Keyword(s):  
Particle Size ◽  
Surface Modification ◽  
Ammonium Nitrate ◽  
Powder Particle ◽  
Nitrate Solution ◽  
Alumina Powder ◽  
Powder Particle Size ◽  
Crystal Type ◽  
Α Al2o3 ◽  
The Impact

The sol - gel method is the effective technique to prepare high purity ultrafine alumina powder. Laser particle size analyzer and scanning electron microscopy were used to study the inflence of pH, leaching of precursor sol, surface modification of alumina powder on the secondary particle size. The impact of leaching sol on powder crystal was tested with X-ray diffraction. The results show that: aluminum nitrate solution showed different appearance with different pH values during titration aluminum nitrate solution with ammonia. When pH=3~5.5, the solution occur through no precipitation to the white precipitate, then the solution becomes relatively thin paste; when the pH was from 6.0 to 6.5, the solution becomes more thick paste. When the pH increased from 7.0 to 8.0, the solution has turned into a more dilute paste. The impact of pH on the particle size is: When the pH increased from 5.5 to 7.0, aluminum powder particle size gradually become thicker and larger. When the pH continues to rise, powder particle size is reduced, when the sol pH value is 8.0, it can get the smallest particle size for alumina powder, up to 548nm. Powder average particle size when adding TEA surfactant to sol is less than the sol without any surfactant particle size from the micrograph. Moreover, particle size is more uniform with TEA surfactant, but powder particle size which did not add surfactant to the sol is clear size differences and the dispersion is poor. When the sol containing surfactant, the effect of surface modification is not obvious. In the case of sol without surfactant powder particle size reduced after the surface modification, then powder surface modification is necessary, it can prevent the powder from congregating. The crystal type is relatively perfect and single α-Al2O3 after filtration, the crystal type without leaching is α-Al2O3 and γ-Al2O3, with a smaller particle size, crystal grain size is relatively smaller. If alumina sol isn’t be leached it contains ammonium nitrate, ammonium nitrate will decompose and release various gases during sintering, the gas emission has an crushed effect on the sintered powder.

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 Waterfall Algorithm as a tool of investigation the geometrical features of granular porous media

2021 ◽  
Author(s):  
Wojciech Sobieski
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Lattice Boltzmann ◽  
Granular Media ◽  
Density Ratio ◽  
Geometrical Features ◽  
Granular Porous Media ◽  
Collision Density ◽  
Boltzmann Method ◽  
The Impact

AbstractThe paper describes the so-called Waterfall Algorithm, which may be used to calculate a set of parameters characterising the spatial structure of granular porous media, such as shift ratio, collision density ratio, consolidation ratio, path length and minimum tortuosity. The study is performed for 1800 different two-dimensional random pore structures. In each geometry, 100 individual paths are calculated. The impact of porosity and the particle size on the above-mentioned parameters is investigated. It was stated in the paper, that the minimum tortuosity calculated by the Waterfall Algorithm cannot be used directly as a representative tortuosity of pore channels in the Kozeny or the Carman meaning. However, it may be used indirect by making the assumption that a unambiguous relationship between the representative tortuosity and the minimum tortuosity exists. It was also stated, that the new parameters defined in the present study are sensitive on the porosity and the particle size and may be therefore applied as indicators of the geometry structure of granular media. The Waterfall Algorithm is compared with other methods of determining the tortuosity: A-Star Algorithm, Path Searching Algorithm, Random Walk technique, Path Tracking Method and the methodology of calculating the hydraulic tortuosity based on the Lattice Boltzmann Method. A very short calculation time is the main advantage of the Waterfall Algorithm, what meant, that it may be applied in a very large granular porous media.

Sign in / Sign up

Export Citation Format

Share Document