scholarly journals Analysis of Powder Binder Separation through Multiscale Computed Tomography

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 329
Author(s):  
Shidi Yang ◽  
Qiaoli Xu ◽  
Chengcheng Liu ◽  
Xin Lu ◽  
Xuanhui Qu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Volume Fraction ◽  
Value Distribution ◽  
Green Body ◽  
Low Resolution ◽  
X Ray ◽  
Powder Particles ◽  
X Ray Computed ◽  
Powder Content ◽  
Submicron Resolution

In this study, X-ray computed tomography was used to analyze powder binder separation in TC4 green bodies. Firstly, for the scanned results of the whole green body, because of the relative low resolution (36 µm), the powder binder separation can only be analyzed by using gray value distribution. Then, local regions (areas near the gate and the central parts) were scanned by using a much higher resolution (2.3 µm). Both of the volume fraction of powder content and gray value distributions indicate that powder particles tend to accumulate in the central parts. Finally, based on the results tested by using submicron resolution (0.8 µm), the effects of the volume and morphology of the powder particles on the powder binder separation were analyzed.

scholarly journals Structural and Morphological Quantitative 3D Characterisation of Ammonium Nitrate Prills by X-Ray Computed Tomography

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1230
Author(s):  
Fabien Léonard ◽  
Zhen Zhang ◽  
Holger Krebs ◽  
Giovanni Bruno
Keyword(s):  
Computed Tomography ◽  
Specific Surface ◽  
Ammonium Nitrate ◽  
Surface Area ◽  
Specific Surface Area ◽  
Volume Fraction ◽  
Fuel Oil ◽  
X Ray ◽  
Oil Retention ◽  
X Ray Computed

The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually referred to as ANFO, is extensively used in the mining industry as a bulk explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the complex pore structure of the AN prills. In this study, we present how X-ray computed tomography (XCT), and the associated advanced data processing workflow, can be used to fully characterise the structure and morphology of AN prills. We show that structural parameters such as volume fraction of the different phases and morphological parameters such as specific surface area and shape factor can be reliably extracted from the XCT data, and that there is a good agreement with the measured oil retention values. Importantly, oil retention measurements (qualifying the efficiency of ANFO as explosives) correlate well with the specific surface area determined by XCT. XCT can therefore be employed non-destructively; it can accurately evaluate and characterise porosity in ammonium nitrate prills, and even predict their efficiency.

Flows Through Real Porous Media: X-Ray Computed Tomography, Experiments, and Numerical Simulations

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Wim-Paul Breugem ◽  
Vincent van Dijk ◽  
René Delfos
Keyword(s):  
Computed Tomography ◽  
Porous Medium ◽  
Ct Scan ◽  
Numerical Simulations ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Immersed Boundary ◽  
Immersed Boundary Methods ◽  
X Ray ◽  
X Ray Computed

Two different direct-forcing immersed boundary methods (IBMs) were applied for the purpose of simulating slow flow through a real porous medium: the volume penalization IBM and the stress IBM. The porous medium was a random close packing of about 9000 glass beads in a round tube. The packing geometry was determined from an X-ray computed tomography (CT) scan in terms of the distribution of the truncated solid volume fraction (either 0 or 1) on a three-dimensional Cartesian grid. The scan resolution corresponded to 19.3 grid cells over the mean bead diameter. A facility was built to experimentally determine the permeability of the packing. Numerical simulations were performed for the same packing based on the CT scan data. For both IBMs the numerically determined permeability based on the Richardson extrapolation was just 10% lower than the experimentally found value. As expected, at finite grid resolution the stress IBM appeared to be the most accurate IBM.

INVESTIGATION OF POLYMER COMPOSITE MATERIAL SAMPLES BY X-RAY COMPUTED TOMOGRAPHY AND PROCESSING OF TOMOGRAMS WITH THE IMAGE OF THE VOLUME FRACTION OF POROSITY

2021 ◽  
pp. 105-113
Author(s):  
A.A. Demidov ◽  
◽  
O.A. Krupnina ◽  
N.A. Mikhaylova ◽  
E.I. Kosarina ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Polymer Composite ◽  
Volume Fraction ◽  
Filter Material ◽  
Polymer Composite Material ◽  
Tomographic Images ◽  
X Ray ◽  
X Ray Computed ◽  
Porosity Volume Fraction

The question of the quality of samples made of polymer composite materials and its verification by x-ray computed tomography is considered. The capabilities of North Star Imaging X5000 tomograph were studied and the samples from PCM were examined for detection and evaluation of the porosity volume fraction. The factors influencing the accuracy of the estimation of the porosity volume fraction are investigated. Namely the size voxel, a filter material, quantity of projections. On the other hand, the size вокселя defines resolution of the digital image, the relation depends on a material of the applied filter a signal/noise, productivity of control worsens with growth of quantity of projections. The choice of optimum values of the listed parametres is necessary for satisfactory quality received tomographic images.

X-Ray Computed Tomography Studies of 3D Meso-Defect Volume Distribution Changes of Cement Paste due to Carbonation

2010 ◽  
Vol 163-167 ◽  
pp. 3061-3066 ◽  
Author(s):  
Jian De Han ◽  
Gang Hua Pan ◽  
Wei Sun ◽  
Cai Hui Wang ◽  
Hui Rong
Keyword(s):  
Computed Tomography ◽  
Cement Paste ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Volume Distribution ◽  
X Ray ◽  
Before And After ◽  
X Ray Computed ◽  
Non Destructive ◽  
Defect Volume

X-ray computed tomography (XCT), a non-destructive test, was used to study three dimensional (3D) meso-defect volume distribution changes of cement paste due to carbonation. The 3D meso-defect volume from 0.02mm3 ~5mm3 before and after carbonation was analyzed through add-on modules of 3D defect analysis. The experimental results show that the meso-defect volume fraction before and after carbonation are 0.7685% and 2.44%, respectively. After carbonation, the smaller defect increased significantly than the bigger defect.

Three-dimensional characterization of powder particles using X-ray computed tomography

2021 ◽  
Vol 40 ◽  
pp. 101913
Author(s):  
Xin Zhou ◽  
Ning Dai ◽  
Xiaosheng Cheng ◽  
Adam Thompson ◽  
Richard Leach
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
X Ray ◽  
Powder Particles ◽  
X Ray Computed

scholarly journals X-ray Computed Tomography Studies on Porosity Distribution in Vacuum Induction Cast Al-7Si Alloys

JOM ◽  
2021 ◽  
Author(s):  
James Mathew ◽  
Mark A. Williams ◽  
Prakash Srirangam
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Volume Fraction ◽  
3D Visualization ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Muffle Furnace ◽  
X Ray ◽  
X Ray Computed

AbstractPorosity in aluminum alloys is a great concern to the casting and automotive industry. In this publication, porosity formation in air-melted and vacuum induction melted (VIM) aluminum alloys was studied and compared to understand its effect on microstructure and mechanical properties of Al-7Si alloys. Al-7Si alloys were cast at 700°C and 900°C in a muffle furnace and VIM furnace. Microstructural results show that the alloys cast in muffle furnace refined the eutectic silicon compared with the cast samples prepared in VIM furnace. X-ray computed tomography (XCT) was used for three-dimensional (3D) visualization and quantification of porosity in these alloys. The volume fraction of pores was observed to be higher in alloy air-melted at 900°C compared with 700°C. XCT results from VIM alloy samples showed no significant porosity when cast at either 700°C or 900°C. The morphology of large pores in alloys air-melted at 700°C represents the formation of shrinkage porosity due to the incomplete flow of molten metal during solidification. Tensile test results show that the elongation property of VIM alloy was increased by more than 20% compared with air-melted alloy. The tensile strength and elongation were observed to be higher for alloy samples cast at 700°C compared with 900°C for both air-melted and VIM alloys. The findings from microstructure, XCT, and tensile tests show that vacuum induction melting improves the mechanical properties of the alloy compared with air-melted alloy.

Void Content Measurement in Fiber Reinforced Plastic Composites by X-Ray Computed Tomography

2018 ◽  
Vol 928 ◽  
pp. 38-44 ◽  
Author(s):  
Mathew John ◽  
Raghu V. Prakash
Keyword(s):  
Computed Tomography ◽  
Volume Fraction ◽  
Void Formation ◽  
Volume Measurement ◽  
Void Volume Fraction ◽  
Void Volume ◽  
Void Content ◽  
X Ray ◽  
Content Measurement ◽  
X Ray Computed

The void formation in FRP composites is unavoidable and the void content measurement is very important to study its deleterious effects on the mechanical properties of the material. Generally destructive methods are used to calculate the void volume fraction. But the recent advances in X-ray computed tomography can be used to detect and quantify the void content in the composites in a non-destructive manner. In this study average area method is proposed and validated for the void volume measurement from the X-ray CT image slices through digital image processing. The effects of void size, shape and position in the accuracy of the measurement is studied and presented here. The void volume fraction of a CFRP laminate manufactured with compression molding technique is calculated by this method and found to be around 1%.

scholarly journals Microscopic Texture of Polypropylene Fiber-Reinforced Concrete with X-Ray Computed Tomography

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Yu Qin ◽  
Hua Wu ◽  
Yong Zheng ◽  
Weina Wang ◽  
Zhijian Yi
Keyword(s):  
Computed Tomography ◽  
Reinforced Concrete ◽  
Coarse Aggregate ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
X Ray ◽  
X Ray Computed ◽  
Polypropylene Fiber Reinforced Concrete

Polypropylene fiber-reinforced concrete (PFRC) is a cement-based composite material with short-cut fibers which has been utilized to provide multidimensional reinforcement and enhance toughness of concrete. However, this improvement is closely related to the microstructural morphology of the concrete. A nondestructive technique using X-ray computed tomography (CT) was therefore used to grasp the microscopic texture of PFRC samples. The results showed that the orientation of microcracks, which appear in the interfacial transition zone, are along the surface of the coarse aggregate. The range of distribution of fibers is proportional to fiber volume fraction. The coarse aggregate influence distribution and orientation of polypropylene fibers whose shape are mainly fold line and curve. The dispersion of pores with small volume is uniform, and the distance between the pores with larger volume is short. The proportion of pores with the diameter in the range 0∼199 μm exceeds 70%, of which the sum of volume exceeds a half of total volume with the amount being about 1% of total amount.

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