Characteristics of 45S5 Bioglass-Ceramics Using Natural Raw Materials

2012 ◽  
Vol 506 ◽  
pp. 174-177
Author(s):  
W. Leenakul ◽  
N. Pisitpipathsin ◽  
P. Kantha ◽  
N. Tawichai ◽  
S. Tigunta ◽  
...  

The aim of this work was to analyze the effect of using rice husk ash (RHA) and bovine bone as raw materials of glass-ceramics based on the SiO2-Na2O-CaO-P2O5system on their physical, mechanical properties and bioactivity. All of the investigated compositions were prepared by melting the glass mixtures at 1300°C for 3 h. The resulting glass samples were heated at different temperatures ranging from 600 to 1000°C with fixed dwell-time for 2 h for crystallization. Phase identification of the prepared glass ceramics was carried out by X-Ray diffraction (XRD) and scanning electron microscope (SEM) techniques. In addition, in vitro test was carried out in stimulated body fluid (SBF). Differential thermal analysis (DTA) showed that the glass transition occurred at 505°C and crystallization at 700°C. The main crystalline phase form in most glass ceramics is a sodium calcium silicate. The optimum heat treatment temperature, at which the maximum mechanical value (620 HV) could be obtained, is around 1000°C. After incubation in SBF for 7 days, all of the samples show good bioactivity in vitro, as evident by the formation of bone like apatite phase.

2019 ◽  
Vol 798 ◽  
pp. 229-234 ◽  
Author(s):  
Puripat Kantha ◽  
Naris Barnthip ◽  
Kamonpan Pengpat ◽  
Tawee Tunkasiri ◽  
Nuttapon Pisitpipathsin

In this work, the thermal treatment temperature effect on phase formation and bioactivity of glass-ceramics based on the SiO2-Na2O-CaO-P2O5 system has been studied. The chemical composition of the system is 45 wt.% SiO2, 24.5 wt.% Na2O, 24.5 wt.% CaO and 6 wt.% P2O5 (45S5). The rice husk ash is used as the natural raw materials instead of commercial SiO2. All of the investigated compositions were prepared by melting the glass mixtures at 1350°C for 3 h. The resulting glass samples were heated at different thermal treatment temperatures ranging from 750 to 1050°C with fixed dwell-time for 4 h for crystallization. Phase identification of the 45S5 glass ceramics was carried out by X-Ray diffraction (XRD). Moreover, the physical properties such as density, porosity and mechanical properties were systematically investigated. It was found that, the increasing of heat treatment temperature led to the increasing of the Na2Ca2Si3O9 phase and obtaining better bioactive behavior after incubation of glass-ceramics in simulated body fluid (SBF) for 7 days. The maximum hardness value of 4.02 GPa was achieved after heating at 1050°C for 4 h. However, the density value has slightly changed with various heat treatment temperatures.


2008 ◽  
Vol 2 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Joanna Podporska ◽  
Marta Błażewicz ◽  
Barbara Trybalska ◽  
Łukasz Zych

Until now the basic methods used in manufacturing of wollastonite have been chemical (melting together with glass crystallization process, chemical coprecipitation) and sol - gel methods. A new and promising way of wollastonite fabrication is controlled pyrolysis of polysiloxane precursors with inorganic fillers. Heat treatment of such mixtures leads to the formation of wollastonite-containing ceramics already at about 1000?C. This is a relatively inexpensive and efficient method which enables to obtain complex shapes of the samples. The aim of this work was to obtain sintered, wollastonite-containing bioceramics and determine its bioactive features. Samples were sintered at three different temperatures: 1000, 1100 and 1200?C. Then the bioactivity of the wollastonite-containing ceramics was investigated by the ?in vitro? test in simulated body fluid. On the basis of the achieved results, it can be assumed that the obtained material possesses bioactive features.


2010 ◽  
Vol 105-106 ◽  
pp. 743-745
Author(s):  
Li Jie Qu ◽  
Bin Li ◽  
Jing Wang ◽  
Yue Mei Gu

Glass-ceramics with desired microstructures and properties are controlled by nucleation and crystallization. The nucleation and crystallization of glass, which include the nucleation, crystal growth rates and the activation energy, are important in understanding the stability of glass in practical applications. The activation energy of crystallization (E) plays an important role in determining the utility of glass ceramic. The amorphous to crystalline transformation in glass can be investigated by isothermal and non-isothermal method which is differential scanning calorimetric (DSC). In the isothermal method, the sample is measured as a function of time, while in the non-isothermal method the sample is recorded as a function of temperature. An advantage of the non-isothermal method is the possibility of reaching a test temperature instantaneously and during the time, which system needs to stabilize. However, the isothermal method does not have this advantage. In the present work, this technique was used to calculate the activation energy of CaO-Al2O3-SiO2-CeO2 glass-ceramics. DSC technique can be used as to determine the optimum heat treatment temperature. The advantage of the DSC technique in study of glass-ceramics is that it requires much less time.


2016 ◽  
Vol 1812 ◽  
pp. 83-88
Author(s):  
Jorge López-Cuevas ◽  
Martín I. Pech-Canul ◽  
Juan C. Rendón-Angeles ◽  
José L. Rodríguez-Galicia ◽  
Carlos A. Gutiérrez-Chavarría

ABSTRACTGlass-ceramics of eutectic composition in the wollastonite [W, CaO⋅SiO2]- tricalcium phosphate [TCP, β-Ca3(PO4)2] binary system were synthesized by using the glass-crystallization method. The parent glass was crystalized at 800-1300 °C for 0.5-5 h. The in vitro bioactivity of the synthesized glass-ceramics was tested in Kokubo’s Simulated Body Fluid (SBF) for 7-21 days, at pH = 7.4 and 37 °C. All materials were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS). The results showed that metastable Apatite phase [Ap, Ca10(PO4)6O], plus W and TCP phases expected according to the binary phase diagram, were formed. Ap was the first phase formed at 900 °C/0.5 h, which was followed by formation of W phase at 900 °C/2 h and of TCP phase at 1200 °C/0.5 h. The relative proportion of the formed crystalline phases was a function of heat treatment temperature and time. A eutectic microstructure was obtained for the materials heat-treated at 1300 °C for 2 or 5 h. All glass-ceramics showed the formation of a hydroxyapatite (HAp)-like layer during the in vitro bioactivity tests. After 21 days of soaking in SBF, the samples treated at 1300 °C/5 h showed a behavior similar to that typically shown by Bioeutectic® material, while the materials heat-treated at lower temperatures tended to form denser HAp-like layers, with similar thicknesses but with higher Ca/P molar ratios.


2012 ◽  
Vol 727-728 ◽  
pp. 1187-1192 ◽  
Author(s):  
Rafaela Silveira Vieira ◽  
Wilbur Trajano Guerin Coelho ◽  
Mônica Beatriz Thürmer ◽  
Juliana Machado Fernandes ◽  
Luis Alberto Santos

The calcium phosphate cements (CPCs) based on α-tricalcium phosphate (α-TCP) are highly attractive for use in medicine and odontology, since they have similar chemical and phase composition of mineral phase of bones (calcium deficient hydroxyapatite (CDHA)). However, one of the biggest difficulties for use of this type of cement is its low mechanical strength due to the presence of undesirable phases, such as β-tricalcium phosphate. The route for obtaining α-TCP is at high temperature by solid state reaction, mixing calcium carbonate and calcium pyrophosphate. The aim of this work was to obtain calcium phosphate cements with improved strength, by studying the obtaining of α-TCP at temperatures of 1300, 1400 and 1500°C. The samples were analyzed by crystalline phases, pH, setting time, particle size, in vitro test (Simulated Body Fluid), porosity, density and compressive strength. The results show that the synthesis temperatures influence strongly the phases of powders obtained and the mechanical properties of cement, being unnecessary quenching for obtaining pure α-TCP.


2009 ◽  
Vol 7 (3) ◽  
pp. 322-327 ◽  
Author(s):  
Lachezar Radev ◽  
Vladimir Hristov ◽  
Irena Michailova ◽  
Bisserka Samuneva

AbstractCeramics, with basic composition based on the CaO-SiO2-P2O5-MgO system with different Ca+ Mg/P+Si molar ratio (R), were prepared via polystep sol-gel technique. The structure of the obtained ceramic materials has been studied by XRD, FTIR spectroscopy, and SEM. X-ray diffraction showed the presence of akermanite and HA for the sample with R = 1.68 and Mg substituted β-TCP and silicocarnotite for the sample with R = 2.16, after thermal treatment at 1200°C/2 h. The obtained results are in good agreement with FTIR. In vitro test for bioactivity in static condition proved that the carbonate containing hydroxyapatite (CO3HA) can be formed on the surface of the synthesized samples. CO3HA consisted of both A- and B-type CO 32− ions. SEM micrographs depicted different forms of HA particles, precipitated on the surface after soaking in 1.5 simulated body fluid (SBF).


2012 ◽  
Vol 509 ◽  
pp. 314-320 ◽  
Author(s):  
Hong Ping Chen ◽  
Hai Zheng Tao ◽  
Qi De Wu ◽  
Xiu Jian Zhao

Li2O-Al2O3(La2O3)-TiO2-P2O5 glass-ceramics were fabricated through heat-treatment of the original glass. The differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical workstation were employed to study the structural, morphology and electrical properties of the samples heat-treated at different temperatures. The results showed that: the glass-ceramics consist of the dominating LiTi2(PO4)3 phases, trifle AlPO4, TiO2 and unknown phases. With the heat-treatment temperature increasing from 700 °C to 1100 °C, the structure of glass-ceramic become denser and grain grew, lithium ion conductivity increased quickly and subsequent cut down gradually. While the specimen was obtained by crystallization at 900 °C for 12 h, the total conductivity of glass-ceramic material come up to the maximum (5.85 ×10-4 S•cm-1) at 25 °C. This inorganic solid electrolyte has a potential application in lithium batteries or other devices.


2018 ◽  
Vol 271 ◽  
pp. 23-27
Author(s):  
Uyat Bayarzul ◽  
Jadambaa Temuujin

Glass ceramics were prepared from fly ash, waste window glass and fluorite rawmaterials. Mixtures of raw materials were melted at 1300, 1400 and 1500 °C for 4 h and quenchedin cold water. The crystallization behavior of glass ceramics was investigated by differentialthermal analysis-thermogravimetry (DTA-TG). Crystallization at various temperatures (700, 800,900 and 1000 °C) for 30 min was used to obtain the glass ceramics. The obtained glass ceramicswere characterized by X-ray diffraction (XRD), light microscopy and hardness test. XRD studyrevealed that the crystallized phases were plagioclase-type minerals (diopside and albite). TheVickers hardness of the glass ceramics increased from 0.80±0.19 GPa to 6.35±0.35GPa and densityranged from 1.44 g/cm3 to 2.42 g/cm3 depending on the treatment temperature. Glass ceramicsprepared from fused glass melted at 1500 °C temperature showed the highest hardness comparedwith those melted at lower temperatures.


2018 ◽  
Vol 766 ◽  
pp. 164-169
Author(s):  
Manlika Kamnoy ◽  
Uraiwan Intatha ◽  
Anocha Munpakdee ◽  
Sukum Eitssayeam ◽  
Tawee Tunkasiri

In this study, the mechanical properties and microstructure of lithium disilicate glass–ceramics in the Li2O-SiO2-Al2O3-K2O-P2O5-ZrO2-CaO glass system were investigated. The glass-ceramics were prepared from the glass melt by casting into mold on hotplate. After that the glass was heat treated at 650-800 °C for 2 h. The heat treatment temperatures were determined from the differential thermal analysis (DTA). The phase formation and microstructure of the glass–ceramics were characterized by X-ray diffraction (XRD) technique and the scanning electron microscopy (SEM). Moreover, the mechanical properties was investigated by Vickers hardness testing. The results indicated that the samples confirmed the occurrence of Li2SiO3, Li2Si2O5, Li3PO4, and LiAlSi2O6 phases in the prepared glass ceramics. The optimum heat treatment temperature results in the physical properties with a high Vickers hardness values in the range of 5.4-5.8 GPa.


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