Effect of zinc oxide on microhardness and sintering behavior of MgO–Al2O3–SiO2 glass–ceramic system

Mirhadi, B.; Mehdikhani, Behzad; Askari, Nayereh

doi:10.1016/j.solidstatesciences.2012.01.010

Cited by 21 publications

(7 citation statements)

References 13 publications

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“…The nucleation temperature at 740°C and crystallization temperature at 910°C for the parent glass (BZnO) was reduced to 654°C and 746°C, respectively, after 15.53 mol % substitution of ZnO into the system. This result can be attributed to the decrease in viscosity of the system with the increase of ZnO as reported by Doremus [14] and Alizadeh et al [15], Kamitakahara et al [11], Mirhadi et al [16] and Srivastar and Pyare [7].…”

Section: In Vitro Bioactivity Analysissupporting

confidence: 52%

In vitro evaluation of bioactivity of SiO2-CaO-P2O5-Na2O-CaF2-ZnO glass-ceramics

Riaz

Zia

Saleemi

et al. 2014

Materials Science-Poland

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Zinc is an essential trace element that stimulates bone formation but it is also known as an inhibitor of apatite crystal growth. In this work addition of ZnO to SiO 2 -CaO-P 2 O 5 -Na 2 O-CaF 2 glass-ceramic system was made by conventional meltquenching technique. DSC curves showed that the addition of ZnO moved the endothermic and exothermic peaks to lower temperatures. X-ray diffraction analysis did not reveal any additional phase caused by ZnO addition and showed the presence of wollastonite and hydroxyapatite crystalline phases only in all the glass-ceramic samples. As bio-implant apatite forming ability is an essential condition, the surface reactivity of the prepared glass-ceramic specimens was studied in vitro in Kokubo's simulated body fluid (SBF) [1] with ion concentration nearly equal to human blood plasma for 30 days at 37°C under static condition. Atomic absorption spectroscopy (AAS) was used to study the changes in element concentrations in soaking solutions and XRD, FT-IR and SEM were used to elucidate surface properties of prepared glass-ceramics, which confirmed the formation of HCAp on the surface of all glass-ceramics. It was found that the addition of ZnO had a positive effect on bioactivity of glassceramics and made it a potential candidate for restoration of damaged bones.

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Section: In Vitro Bioactivity Analysissupporting

confidence: 52%

In vitro evaluation of bioactivity of SiO2-CaO-P2O5-Na2O-CaF2-ZnO glass-ceramics

Riaz

Zia

Saleemi

et al. 2014

Materials Science-Poland

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“…Glass-ceramic materials are an excellent choice for the LTCC process; these materials can be fabricated at very lower sintering temperatures compared to the temperatures necessary for normal ceramic materials [3][4][5][6]. Compared to normal ceramic materials, LTCC packages prepared by the glass-ceramic process have been proven to demonstrate higher signal propagation speeds and better stability and chemical durability; they also have a low thermal expansion coefficient and a low cost [7,8] Glass ceramics are composed of materials with one or more crystalline phases immersed in a residual glassy phase.…”

Section: Introductionmentioning

confidence: 99%

Effect of a ZnO addition on the thermal properties of diopside-based glass ceramics for LED packages

Lee¹,

Kang²

2016

ces

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Diopside is known to be a ceramic phase with excellent thermal properties (~2.7 W/mK), but the thermal conductivity is not high enough to apply it as a LED packaging material. The chip and PCB (printed circuit board) will deteriorate if the heat is not released out of the LED device. In this study, glass-frit CaO-MgO-SiO2 systems with a stoichiometric diopside phase composition containing ZnO of various types and amounts were fabricated. The thermal conductivity, density, and shrinkage as a function of the type of ZnO added were studied to investigate the feasibility of utilizing diopside-based glass ceramics in LED packaging applications. It was found that at temperatures below 1000℃, it is possible to fabricate diopside/ZnO composites with thermal conductivity values of approximately 5.7 W/mK, 2.1 times higher than that of pure diopside, by adding single-crystalline ZnO filler to the mother glass. The diopside/ZnO composites fabricated in this study can therefore be applied to LED packaging materials. They are also suitable for the LTCC process.

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“…In the crystallization of MgO-Al 2 O 3 -SiO 2 system, with the sequential addition of ZnO and with B 2 O 3 and ZrO 2 additions, gahnite (ZnO·Al 2 O 3 ) and mullite were synthesized and the hardness increase with the increase in gahnite crystals. 11 In this paper the results of the effect of partial substitution of MgO by ZnO in the cordierite parent glass, and also some additions of fluorine sources, i.e., CaF 2 , MgF 2 and AlF 3 , on the crystallization process are reported. The thermal effect, microstructure and some properties were studied too.…”

Section: Introductionmentioning

confidence: 99%

Sintered gahnite–cordierite glass-ceramic based on raw materials with different fluorine sources

Hamzawy

Hussain

2015

Bull Mater Sci

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Glass-ceramic based on Zn-containing cordierite was prepared from kaolin, silica'sand and commercial ZnO. The addition of AlF 3 , MgF 2 and CaF 2 was performed as nucleation catalysts. Dark brown glasses were obtained from the glass batches. The transformation and crystallization temperatures were in the range of 739-773 and 972-1007 • C, respectively. Gahnite, cordierite and very little enstatite were the development crystalline phases through the heating and sintering process between 1000 and 1340 • C. The microstructure of crystallized samples at 1340 • C showed the appearance of dominant euhedral octahedral crystals of gahnite and hexagonal cordierite, in the low micro-scale, disseminated in the glassy matrix. The microanalysis of the crystallized samples indicated that Zn and Mg may replace each other in gahnite and cordierite structure. Densities of the crystallized samples were between 2.2517 and 2.5278 g cm −3 . The thermal expansion of the crystallized samples was ranging from 19.22 to 59.30 × 10 −7• C −1 . However, the higher crystallization of both cordierite and gahnite accompany with the higher values of densities and the lower values of coefficient of thermal expansion.

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Effect of zinc oxide on microhardness and sintering behavior of MgO–Al2O3–SiO2 glass–ceramic system

Cited by 21 publications

References 13 publications

In vitro evaluation of bioactivity of SiO2-CaO-P2O5-Na2O-CaF2-ZnO glass-ceramics

In vitro evaluation of bioactivity of SiO2-CaO-P2O5-Na2O-CaF2-ZnO glass-ceramics

Effect of a ZnO addition on the thermal properties of diopside-based glass ceramics for LED packages

Sintered gahnite–cordierite glass-ceramic based on raw materials with different fluorine sources

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