scholarly journals 3D-printed jars for ball-milling experiments monitoredin situby X-ray powder diffraction

2017 ◽  
Vol 50 (4) ◽  
pp. 994-999 ◽  
Author(s):  
Nikolay Tumanov ◽  
Voraksmy Ban ◽  
Agnieszka Poulain ◽  
Yaroslav Filinchuk

Mechanochemistry is flourishing in materials science, but a characterization of the related processes is difficult to achieve. Recently, the use of plastic jars in shaker mills has enabledin situX-ray powder diffraction studies at high-energy beamlines. This paper describes an easy way to design and manufacture these jars by three-dimensional (3D) printing. A modified wall thickness and the use of a thin-walled sampling groove and a two-chamber design, where the milling and diffraction take place in two communicating volumes, allow for a reduced background/absorption and higher angular resolution, with the prospect for use at lower-energy beamlines. 3D-printed polylactic acid jars show good mechanical strength and they are also more resistant to solvents than jars made of polymethyl methacrylate. The source files for printing the jars are available as supporting information.

2018 ◽  
Vol 941 ◽  
pp. 943-948
Author(s):  
Katja Hauschildt ◽  
Andreas Stark ◽  
Hilmar Burmester ◽  
Ursula Tietze ◽  
Norbert Schell ◽  
...  

TiAl alloys are increasingly used as a lightweight material, for example in aero engines, which also leads to the requirement for suitable repair techniques. Transient liquid phase bonding is a promising method for the closure of cracks (in non-critical or non-highly loaded areas). The brazing solder Ti-24Ni was investigated for brazing the alloy Ti-45Al-5Nb-0.2B-0.2C (in at. %). After brazing, the joint exhibits different microstructures and phase compositions. The transient liquid phase bonding process was investigated in the middle of the joint region in situ to acquire time resolved information of the phases, their development, and thus the brazing process. These investigations were performed using high-energy X-ray diffraction at the “High-Energy Materials Science” beamline HEMS, located at the synchrotron radiation facility PETRA III at DESY in Hamburg, Germany. For this, we used an induction furnace, which is briefly described here. During the analysis of the diffraction data with Rietveld refinement, the amount of liquid was refined with Gaussian peaks and thus could be quantified. Furthermore, while brazing four different phases occurred in the middle of the joint region over time. Additionally, the degree of ordering of the βo phase was determined with two ideal stoichiometric phases (completely ordered and disordered). Altogether, the phase composition changed clearly over the first six hours of the brazing process.


2007 ◽  
Vol 40 (6) ◽  
pp. 999-1007 ◽  
Author(s):  
Ángeles G. De la Torre ◽  
Khadija Morsli ◽  
Mohammed Zahir ◽  
Miguel A.G. Aranda

The clinkerization processes to form belite clinkers, with theoretical compositions close to 60 wt% of Ca2SiO4, have been studiedin situby high-resolution high-energy (λ = 0.30 Å) synchrotron X-ray powder diffraction. In order to obtain active belite cements, different amounts of K2O, Na2O and SO3have been added. The existence range of the high-temperature phases has been established and, furthermore, Rietveld quantitative phase analyses at high temperature have been performed for all patterns. The following high-temperature reactions have been investigated: (i) polymorphic transformations of dicalcium silicate, \alpha_{\rm L}'-Ca2SiO4↔ \alpha_{\rm H}'-Ca2SiO4from 1170 to 1230 K, and \alpha_{\rm H}'-Ca2SiO4↔ α-Ca2SiO4from 1500 to 1600 K; (ii) melting of the aluminates phases, Ca3Al2O6and Ca4(Al2Fe2)O10, above ∼1570 K; and (iii) reaction of Ca2SiO4with CaO to yield Ca3SiO5above ∼1550 K. Moreover, in all the studied compositions the temperature of the polymorphic transformation \alpha_{\rm H}'-Ca2SiO4↔ α-Ca2SiO4has decreased with the addition of activators. Finally, active belite clinkers were produced as the final samples contained α-belite phases.


2012 ◽  
Vol 49 (10) ◽  
pp. 1212-1220 ◽  
Author(s):  
Dinh Hong Doan ◽  
Pierre Delage ◽  
Jean François Nauroy ◽  
Anh Minh Tang ◽  
Souhail Youssef

The microstructure of oil sand samples extracted at a depth of 75 m from the estuarine Middle McMurray Formation (Alberta, Canada) has been investigated using high resolution three-dimensional (3D) X-ray microtomography (µCT) and cryo scanning electron microscopy (CryoSEM). µCT images evidenced some dense areas composed of highly angular grains surrounded by fluids, which are separated by larger pores full of gas. In dense areas, 3D image analysis provided porosity values comparable with in situ log data and macroscopic laboratory determinations, showing that they are representative of intact states. µCT hence provided some information on the morphology of the cracks and disturbance created by gas expansion. The CryoSEM technique, in which the sample is freeze fractured within the SEM chamber prior to observation, provided pictures in which the (frozen) bitumen clearly appears between the sand grains. No evidence of the existence of a thin connate water layer between grains and the bitumen, frequently mentioned in the literature, has been obtained. Bitumen appears to strongly adhere to the grains, with some grains being completely coated. The curved shape of some bitumen menisci suggests a bitumen wet behaviour.


2020 ◽  
Vol 104 (3) ◽  
pp. 1424-1435
Author(s):  
Michael W. Knauf ◽  
Craig P. Przybyla ◽  
Paul A. Shade ◽  
Jun‐Sang Park ◽  
Andrew J. Ritchey ◽  
...  

2018 ◽  
Vol 156 ◽  
pp. 330-341 ◽  
Author(s):  
Chi Xu ◽  
Xuan Zhang ◽  
Yiren Chen ◽  
Meimei Li ◽  
Jun-Sang Park ◽  
...  

2016 ◽  
Vol 23 (2) ◽  
pp. 501-509
Author(s):  
Mostafa El Ashmawy ◽  
Hany Amer ◽  
Mahmoud Abdellatief

The correlation between the thermoluminescence (TL) response of nanocrystalline LiF and its microstructure was studied. To investigate the detailed TL mechanism, the glow curves of nanocrystalline LiF samples produced by high-energy ball-milling were analyzed. The microstructure of the prepared samples was analyzed by synchrotron X-ray powder diffraction (XRPD) at room temperature. Then, the microstructure of a representative pulverized sample was investigated in detail by performingin situXRPD in both isothermal and non-isothermal modes. In the present study, the dislocations produced by ball-milling alter the microstructure of the lattice where the relative concentration of the vacancies, responsible for the TL response, changes with milling time. An enhancement in the TL response was recorded for nanocrystalline LiF at high-temperature traps (after dislocations recovery starts >425 K). It is also found that vacancies are playing a major role in the dislocations recovery mechanism. Moreover, the interactions among vacancies–dislocations and/or dislocations–dislocations weaken the TL response.


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