Results 171 to 180 of about 1,867 (215)

Crack-healing in spinel (MgAl2O4) ceramic

Materials Science and Engineering: A, 2015
Abstract This paper reports the crack-healing behavior in spinel ceramic. Spinel nanopowder was synthesized via mechanical activation with subsequent annealing of magnesium carbonate and aluminum hydroxide. The produced nanopowder was uniaxially pressed and then sintered at 1200 °C for 1 h.
Fariborz Tavangarian, Guoqiang Li
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Inversion in synthetic spinel: Fluorescence of Cr3+ ions in MgAl2O4 spinel ceramics

Journal of Luminescence, 2020
Abstract The fluorescence spectra of probe Cr3+ ions in MgAl2O4 spinel ceramics have been studied. The analysis of the spectra shows that the normal non-inverse spinel phase dominates the samples. The possibility of obtaining normal spinel by the standard high-temperature ceramics synthesis is established.
S.P. Feofilov, A.B. Kulinkin, N.M. Khaidukov   +2 more
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Structural analysis on spinel (MgAl2O4) for application in spinel-bonded castables

Ceramics International, 2009
Abstract An intimate mixture of common hydrated magnesium salt and cheaper boehmite sol had been used as a cost-effective precursor of reactive nanometric spinel (1:1) powder. It was gelled at controlled pH, temperature and time, and calcined at significantly lower temperature after soft mechanochemical treatment.
A. Banerjee, S. Das, S. Misra, S. Mukhopadhyay   +3 more
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Tribological Behaviour of Transparent Spinel (MgAl2O4)

2022
The wear behaviour of transparent magnesium aluminate (MgAl2O4) was investigated for unlubricated sliding against chrome steel balls under different load (5, 10, and 15 N) conditions. The sliding speed and sliding distance were retained constant, i.e., 260 mms-1 and 157 m, respectively.
Divyansh Mittal, Jan Hostasa, Rajiv Kumar, Sandan Kumar Sharma   +3 more
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Spectroscopic properties of Nd3+ in MgAl2O4 spinel nanocrystals

Journal of Alloys and Compounds, 2012
Abstract Nd 3+ doped MgAl 2 O 4 spinel nanocrystals have been prepared by the sol–gel method. Their size decreases from 12 to 7 nm with increasing Nd 3+ concentration from 0.1 to 5%, respectively. Some crystal field components of the Nd 3+ energy levels in MgAl 2 O 4 spinel were found from the 300 K reflectance absorption and the 77 K emission ...
P.J. Dereń, K. Maleszka-Bagińska, P. Głuchowski, M.A. Małecka   +3 more
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Piezo- and thermo-optic behavior of spinel (MgAl2O4)

Journal of Solid State Chemistry, 1975
Abstract The piezo- and thermo-optic properties of oxides are extremely interesting and fascinating, since in some oxides such as vitreous silica, α-quartz, etc., the refractive index increases with hydrostatic pressure, while in some others such as MgO, SrTiO 3 , α-Al 2 O 3 , etc., it decreases with pressure.
K. Vedam, J.L. Kirk, B.N.N. Achar
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The nature of Cr(III) luminescence in MgAl2O4 spinel

Journal of Luminescence, 1988
Abstract The broad-band emission of Cr(III) in the MgAl2O4 synthetic spinel was observed. Following the absorption measurements and excitation wavelength dependence of luminescence spectra the nature of luminescence is combined with two different Cr(III) sites in this crystal.
W. Strȩk, P. Dereń, B. Jezowska-Trzebiatowska   +2 more
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Slip Systems in Stoichiometric MgAl2O4 Spinel

1975
The mechanical properties of stoichiometric MgAl2O3 spinel single crystals have been investigated at high temperatures (∿1800°C). The slip system has been determined by slip trace analysis and electron microscopy to be {111} . This behavior is rationalized by analyzing the changes in atomic configuration around dissociated dislocations as they move ...
L. Hwang, A. H. Heuer, T. E. Mitchell
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The Brittle to Ductile Transition In MgAl2O4 Spinel

1995
The brittle to ductile transition in ceramic materials is often referred to as the ductile to brittle transition in the metallurgical literature.1–4 It has been a topic of interest in crystalline ceramics for nearly half a century, since the early efforts to develop “ductile” ceramics in the 1950’s. Although there have been efforts to address the topic
Ronald L. Stewart, Richard C. Bradt
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Dynamic response of transparent ceramic MgAl2O4 spinel

Scripta Materialia, 2011
The quasistatic and dynamic compressive strengths of transparent spinel (MgAl2O4) specimens with grain sizes of 0.4 and 1.4 μm are measured. The measured strengths and rate sensitivities of the spinel specimens are compared with another transparent ceramic material, AlON, with significantly coarser grains.
J. Kimberley, K.T. Ramesh
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