Understanding the efficacy of micro-CT to analyse high speed sintering parts

2016 ◽  
Vol 22 (1) ◽  
pp. 152-161 ◽  
Author(s):  
Davood Rouholamin ◽  
Neil Hopkinson
Keyword(s):  
Computed Tomography ◽  
High Speed ◽  
3D Structure ◽  
Morphological Properties ◽  
Micro Computed Tomography ◽  
Elongation At Break ◽  
Content Type ◽  
Nylon 12 ◽  
Non Destructive ◽  
Suitable Technique

Purpose – The purpose of this study was to assess the suitability of micro-computed tomography as a non-destructive method to investigate the morphology of nylon 12 parts produced by high-speed sintering (HSS). The investigation of the effect of changes in the lamp power on the properties of the fabricated parts was another purpose of this study. Design/methodology/approach – Nylon 12 parts were manufactured using HSS with various lamp powers. Morphological properties of the parts were measured using micro-computed tomography. Ultimate tensile strength, elongation at break and Young’s modulus of the prepared parts were determined and compared. The effect of lamp power on the properties of the parts was then studied. Findings – This paper proposes micro-computed tomography as a suitable technique to study the 3D structure of the parts produced by HSS. The effects of lamp power on the properties of the produced parts were also discussed. Practical implications – The findings could result in an improvement in customisation of the parts for various applications through varying the lamp power. The level of lamp power could be tailored to obtain suitable part properties for a target application. Originality/value – This study strengthens the fact that HSS is a promising additive manufacturing technique to produce nylon 12 parts, and the properties of the parts could be maximised using a suitable level of lamp power. The results showed that micro-computed tomography could be used as an efficient technique to investigate the morphology of the sintered parts.

scholarly journals Characterisation of 3D printed sand moulds using micro-focus X-ray computed tomography

2019 ◽  
Vol 25 (2) ◽  
pp. 404-416 ◽  
Author(s):  
Tharmalingam Sivarupan ◽  
Mohamed El Mansori ◽  
Keith Daly ◽  
Mark Noel Mavrogordato ◽  
Fabrice Pierron
Keyword(s):  
Computed Tomography ◽  
Gas Permeability ◽  
Experimental Result ◽  
Pore Connectivity ◽  
Content Type ◽  
X Ray ◽  
3D Printed ◽  
X Ray Computed ◽  
Sand Mould ◽  
Non Destructive

Purpose Micro-focus X-ray computed tomography (CT) can be used to quantitatively evaluate the packing density, pore connectivity and provide the basis for specimen derived simulations of gas permeability of sand mould. This non-destructive experiment or following simulations can be done on any section of any size sand mould just before casting to validate the required properties. This paper aims to describe the challenges of this method and use it to simulate the gas permeability of 3D printed sand moulds for a range of controlling parameters. The permeability simulations are compared against experimental results using traditional measurement techniques. It suggests that a minimum volume of only 700 × 700 × 700 µm3 is required to obtain, a reliable and most representative than the value obtained by the traditional measurement technique, the simulated permeability of a specimen. Design/methodology/approach X-ray tomography images were used to reconstruct 3D models to simulate them for gas permeability of the 3D printed sand mould specimens, and the results were compared with the experimental result of the same. Findings The influence of printing parameters, especially the re-coater speed, on the pore connectivity of the 3D printed sand mould and related permeability has been identified. Characterisation of these sand moulds using X-ray CT and its suitability, compared to the traditional means, are also studied. While density and 3PB strength are a measure of the quality of the moulds, the pore connectivity from the tomographic images precisely relates to the permeability. The main conclusions of the present study are provided below. A minimum required sample size of 700 × 700 × 700 µm3 is required to provide representative permeability results. This was obtained from sand specimens with an average sand grain size of 140 µm, using the tomographic volume images to define a 3D mesh to run permeability calculations. Z-direction permeability is always lower than that in the X-/Y-directions due to the lower values of X-(120/140 µm) and Y-(101.6 µm) resolutions of the furan droplets. The anisotropic permeability of the 3D printed sand mould is mainly due to, the only adjustable, X-directional resolution of the furan droplets; the Y-directional resolution is a fixed distance, 102.6 µm, between the printhead nozzles and the Z-directional one is usually, 280 µm, twice the size of an average sand grain.A non-destructive and most representative permeability value can be obtained, using the computer simulation, on the reconstructed 3D X-ray tomography images obtained on a specific location of a 3D printed sand mould. This saves time and effort on printing a separate specimen for the traditional test which may not be the most representative to the printed mould. Originality/value The experimental result is compared with the computer simulated results.

scholarly journals Morphological Properties of Gastropod Shells in a Warmer and More Acidic Future Ocean Using 3D Micro-Computed Tomography

2021 ◽  
Vol 8 ◽  
Author(s):  
Eva Chatzinikolaou ◽  
Kleoniki Keklikoglou ◽  
Panos Grigoriou
Keyword(s):  
Computed Tomography ◽  
Ambient Temperature ◽  
Ocean Acidification ◽  
Eastern Mediterranean ◽  
Morphological Properties ◽  
Micro Computed Tomography ◽  
Intergovernmental Panel ◽  
Noticeable Effect ◽  
Change Models ◽  
Experimental Treatments

The increased absorption of atmospheric CO2 by the ocean reduces pH and affects the carbonate chemistry of seawater, thus interfering with the shell formation processes of marine calcifiers. The present study aims to examine the effects of ocean acidification and warming on the shell morphological properties of two intertidal gastropod species, Nassarius nitidus and Columbella rustica. The experimental treatments lasted for 3 months and combined a temperature increase of 3°C and a pH reduction of 0.3 units. The selected treatments reflected the high emissions (RCP 8.5) “business as usual” scenario of the Intergovernmental Panel on Climate Change models for eastern Mediterranean. The morphological and architectural properties of the shell, such as density, thickness and porosity were examined using 3D micro-computed tomography, which is a technique giving the advantage of calculating values for the total shell (not only at specific points) and at the same time leaving the shells intact. Nassarius nitidus had a lower shell density and thickness and a higher porosity when the pH was reduced at ambient temperature, but the combination of reduced pH and increased temperature did not have a noticeable effect in comparison to the control. The shell of Columbella rustica was less dense, thinner and more porous under acidic and warm conditions, but when the temperature was increased under ambient pH the shells were thicker and denser than the control. Under low pH and ambient temperature, shells showed no differences compared to the control. The vulnerability of calcareous shells to ocean acidification and warming appears to be variable among species. Plasticity of shell building organisms as an acclimation action toward a continuously changing marine environment needs to be further investigated focusing on species or shell region specific adaptation mechanisms.

scholarly journals Influence of Drilling Technique on the Radiographic, Thermographic, and Geomorphometric Effects of Dental Implant Drills and Osteotomy Site Preparations

2020 ◽  
Vol 9 (11) ◽  
pp. 3631
Author(s):  
Lara Fraguas de San José ◽  
Filippo Maria Ruggeri ◽  
Roberta Rucco ◽  
Álvaro Zubizarreta-Macho ◽  
Jorge Alonso Pérez-Barquero ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Dental Implant ◽  
High Speed ◽  
Digital Camera ◽  
Study Groups ◽  
Site Preparation ◽  
Osteotomy Site ◽  
Study Group ◽  
Micro Computed Tomography ◽  
Drilling Technique

The aim of this comparative study is to analyze the influence of drilling technique on the radiographic, thermographic, and geomorphometric effects of dental implant drills and osteotomy site preparations. One hundred and twenty osteotomy site preparations were performed on sixty epoxy resin samples using three unused dental implant drill systems and four drilling techniques performed with a random distribution into the following study groups: Group A: drilling technique performed at 800 rpm with irrigation (n = 30); Group B: drilling technique performed at 45 rpm without irrigation (n = 30); Group C: drilling technique performed at 45 rpm with irrigation (n = 30); and Group D: drilling technique performed at 800 rpm without irrigation (n = 30). The osteotomy site preparation morphologies performed by the 4.1 mm diameter dental implant drills from each study group were analyzed and compared using a cone beam computed tomography (CBCT) scan. The termographic effects generated by the 4.1 mm diameter dental implant drills from each study group were registered using a termographic digital camera and the unused and 4.1 mm diameter dental implant drills that were used 30 times from each study group were exposed to a micro computed tomography (micro-CT) analysis to obtain a Standard Tessellation Language (STL) digital files that determined the wear comparison by geomorphometry. Statistically significant differences were observed between the thermographic and radiographic results of the study groups (p < 0.001). The effect of cooling significatively reduced the heat generation during osteotomy site preparation during high-speed drilling; furthermore, osteotomy site preparation was not affected by the wear of the dental implant drills after 30 uses, regardless of the drilling technique.

scholarly journals Synchrotron Micro Computed Tomography for Non-destructive 3D Studies of Fossil Fish

2020 ◽  
Vol 26 (S2) ◽  
pp. 1252-1254
Author(s):  
Lisa Van Loon ◽  
Neil Banerjee ◽  
Don Brinkman
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
Fossil Fish ◽  
Non Destructive

Non-Destructive Assaying Gold Jewellery Using Dual-Energy Micro-Computed Tomography

2015 ◽  
Vol 73 (3) ◽  
Author(s):  
Jaafar Abdullah ◽  
Abibullah Samsudin ◽  
Nor Laili Omar ◽  
Hafizza Abdul Manan
Keyword(s):  
Computed Tomography ◽  
Matrix Effects ◽  
Visual Observation ◽  
Dual Energy ◽  
Micro Computed Tomography ◽  
Tomographic Images ◽  
X Ray ◽  
Challenging Tasks ◽  
Tomography Method ◽  
Non Destructive

Determining the fineness of gold jewelleries remains one of the most challenging tasks in gold trading. The existing technology of gold testing is inadequate, allowing gold counterfeiting worldwide. The most popular non-destructive method for analysis of gold jewelleries is X-ray fluorescence technique. However, the technique is limited to surface only and it is also greatly influenced by matrix effects. In this paper, dual-energy X-ray micro-computed tomography method was proposed to assay gold jewelleries. Experimental results demonstrated that grey values of reconstructed tomographic images in combination with advanced image analysis procedures could be used to detect fake jewelleries. Due to the uniqueness of X-ray absorption, the technique was also capable of identifying different materials in gold jewelleries. Further analysis on sectioned-earrings samples using X-ray diffraction techniques and visual observation confirmed all tomographic findings.  

Evaluation of a Continuous-Rotation, High-Speed Scanning Protocol for Micro-Computed Tomography

2011 ◽  
Vol 35 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Hans Ulrich Kerl ◽  
Cristina T. Isaza ◽  
Hanne Boll ◽  
Sebastian J. Schambach ◽  
Ingo S. Nolte ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Speed ◽  
Micro Computed Tomography ◽  
Scanning Protocol ◽  
Continuous Rotation

scholarly journals Quantitative 4D X-ray microtomography under extreme conditions: a case study on magma migration

2021 ◽  
Vol 28 (5) ◽  
Author(s):  
Elena Giovenco ◽  
Jean-Philippe Perrillat ◽  
Eglantine Boulard ◽  
Andrew King ◽  
Nicolas Guignot ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Pressure ◽  
High Temperature ◽  
High Speed ◽  
High Efficiency ◽  
Morphological Properties ◽  
Extreme Conditions ◽  
Temporal Dimension ◽  
Angular Aperture ◽  
X Ray

X-ray computed tomography (XCT) is a well known method for three-dimensional characterization of materials that is established as a powerful tool in high-pressure/high-temperature research. The optimization of synchrotron beamlines and the development of fast high-efficiency detectors now allow the addition of a temporal dimension to tomography studies under extreme conditions. Presented here is the experimental setup developed on the PSICHE beamline at SOLEIL to perform high-speed XCT in the Ultra-fast Tomography Paris–Edinburgh cell (UToPEc). The UToPEc is a compact panoramic (165° angular aperture) press optimized for fast tomography that can access 10 GPa and 1700°C. It is installed on a high-speed rotation stage (up to 360° s−1) and allows the acquisition of a full computed tomography (CT) image with micrometre spatial resolution within a second. This marks a major technical breakthrough for time-lapse XCT and the real-time visualization of evolving dynamic systems. In this paper, a practical step-by-step guide to the use of the technique is provided, from the collection of CT images and their reconstruction to performing quantitative analysis, while accounting for the constraints imposed by high-pressure and high-temperature experimentation. The tomographic series allows the tracking of key topological parameters such as phase fractions from 3D volumetric data, and also the evolution of morphological properties (e.g. volume, flatness, dip) of each selected entity. The potential of this 4D tomography is illustrated by percolation experiments of carbonate melts within solid silicates, relevant for magma transfers in the Earth's mantle.

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