scholarly journals The Crystallization Behaviors of SiO2-Al2O3-CaO-MgO-TiO2 Glass-Ceramic Systems

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 794
Author(s):  
Feifei Lai ◽  
Mei Leng ◽  
Jiangling Li ◽  
Qingcai Liu
Keyword(s):  
Mechanical Properties ◽  
Glass Ceramic ◽  
Crystalline Phase ◽  
Three Dimensional ◽  
Glass Ceramics ◽  
Exothermic Peak ◽  
Obvious Effect ◽  
Prepared Glass ◽  
Main Crystalline Phase ◽  
Hardness Values

To evaluate the crystallization behavior of Ti-bearing blast furnace slag-based glass ceramics, SiO2-Al2O3-CaO-MgO-TiO2 systems with various TiO2 were investigated. The crystallization process and mechanical properties were analyzed. The results show that with TiO2 increasing, exothermic peak temperature (Tp) decreases, and the crystallization is promoted by the introduction of TiO2. A small amount of TiO2 (≤4%) addition can significantly promote crystallization, and when TiO2 continues to increase, the crystallization is decreased slightly. The Avrami parameter (n) of all samples is less than 4, indicating that in prepared glass-ceramics, it is hard to achieve three-dimensional crystal growth. The main crystalline phase is akermanite–gehlenite. The addition of TiO2 has no obvious effect on the type of main crystalline phase. The prepared glass-ceramic with 4% TiO2 show good mechanical properties with the hardness values of 542.67 MPa. The recommended content of TiO2 is 4% for preparing glass-ceramics.

scholarly journals Two-Body and Three-Body Wear Behavior of a Dental Fluorapatite Glass-Ceramic

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 580 ◽  
Author(s):  
Gaoqi Wang ◽  
Yunkai Li ◽  
Shouren Wang ◽  
Xuefeng Yang ◽  
Yujing Sun
Keyword(s):  
Mechanical Properties ◽  
Glass Ceramic ◽  
Wear Behavior ◽  
Glass Ceramics ◽  
Sintering Process ◽  
Main Crystalline Phase ◽  
Natural Teeth ◽  
Three Body ◽  
Dry Water ◽  
Shaped Glass

As a veneering porcelain coating of dental prosthesis, two-body and three-body wear behavior of dental glass-ceramic with the main crystalline phase of fluorapatite has not been comprehensively studied. In this work, a self-made fluorapatite glass-ceramic was synthesized and the mechanical and tribological performances of the glass-ceramic were tested, comparing with a commercial feldspathic glass-ceramic. The friction and wear experiments were performed between disk-shaped glass-ceramics and natural teeth in two-body (dry, water, saliva) and three-body (slurry) modes, respectively. Results showed that good mechanical properties of fluorapatite glass-ceramic can be achieved by the sintering process. In both two-body and three-body modes, the fluorapatite glass-ceramic had a smaller friction coefficient and wear rate and caused less damage on antagonistic teeth than the feldspathic glass-ceramic. The greater mechanical properties give fluorapatite glass-ceramic a better wear resistance and reduce the adhesive wear.

Mechanical Properties and Microstructure of Li2O-SiO2-P2O5-Al2O3-K2O-CaO Glass-Ceramics

2018 ◽  
Vol 766 ◽  
pp. 164-169
Author(s):  
Manlika Kamnoy ◽  
Uraiwan Intatha ◽  
Anocha Munpakdee ◽  
Sukum Eitssayeam ◽  
Tawee Tunkasiri
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Vickers Hardness ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Heat Treated ◽  
Prepared Glass ◽  
Optimum Heat ◽  
Hardness Values

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.

scholarly journals A Durable and Self-Cleaning Superhydrophobic Surface Prepared by Precipitating Flower-Like Crystals on a Glass-Ceramic Surface

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1642
Author(s):  
Haiqing Fu ◽  
Shuo Liu ◽  
Lanlin Yi ◽  
Hong Jiang ◽  
Changjiu Li ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Superhydrophobic Surface ◽  
Three Dimensional ◽  
Strong Acid ◽  
Ceramic Surface ◽  
Sliding Angle ◽  
Water Contact ◽  
Prepared Glass ◽  
Self Cleaning ◽  
Dual Scale

Herein, a superhydrophobic surface with superior durability was fabricated on a glass-ceramic surface by crystallization, hydrofluoric acid (HF) etching, and surface grafting. The as-prepared glass-ceramic surface was composed of three-dimensional flower-like micro-clusters, which were self-assembled from numerous nanosheets. Such a dual-scale rough surface exhibited superhydrophobicity, with a water contact angle (WCA) of 170.3° ± 0.1° and a sliding angle (SA) of ~2° after grafting with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS-17). This can be attributed to the synergistic effect between the dual-scale structure and surface chemistry. Furthermore, this surface exhibited excellent self-cleaning properties, stability against strong acid and strong alkali corrosion, and anti-stripping properties.

scholarly journals Impact of Morphology and Microstructure on the Mechanical Properties of Ge-As-Pb-Se Glass Ceramics

2020 ◽  
Vol 10 (8) ◽  
pp. 2836 ◽  
Author(s):  
Rashi Sharma ◽  
Rebecca Welch ◽  
Myungkoo Kang ◽  
Claudia Goncalves ◽  
Cesar Blanco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Vickers Hardness ◽  
Glass Ceramic ◽  
Volume Fraction ◽  
Glass Ceramics ◽  
Post Heat Treatment ◽  
Base Glass ◽  
Parent Glass ◽  
Crystal Phases

The impact of base glass morphology and post heat-treatment protocol on the mechanical properties (Vickers hardness and Young’s modulus) of a multi-component glass-ceramic was examined. Two parent chalcogenide glasses with identical composition but varying morphology (homogeneous and phase separated) were evaluated for their mechanical properties following identical thermal processing to induce crystallization. The nucleation and growth rates of the starting materials were compared for the two glasses, and the resulting crystal phases and phase fractions formed through heat treatment were quantified and related to measured mechanical properties of the glass ceramics. The presence of a Pb-rich amorphous phase with a higher crystal formation tendency in the phase-separated parent glass significantly impacted the volume fraction of the crystal phases formed after heat-treatment. Pb-rich cubic crystal phases were found to be dominant in the resulting glass ceramic, yielding a minor enhancement of the material’s mechanical properties. This was found to be less than a more moderate enhancement of mechanical properties due to the formation of the dominant needle-like As2Se3 crystallites resulting from heat treatment of the homogeneous, commercially melted parent glass. The greater enhancement of both Vickers hardness and modulus in this glass ceramic attributable to the high-volume fraction of anisotropic As2Se3 crystallites in the post heat-treated commercial melt highlights the important role base glass morphology can play on post heat-treatment microstructure.

Influence of NaCl on Mechanical Properties and Microstructure of Cement Stone

2013 ◽  
Vol 700 ◽  
pp. 136-139
Author(s):  
Xin Tang ◽  
Jin Huang
Keyword(s):  
Mechanical Properties ◽  
Sodium Chloride ◽  
Crystalline Phase ◽  
The Other ◽  
Cement Stone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Main Crystalline Phase ◽  
Gel Phase ◽  
Scanning Electron

The mechanical properties and microstructure of cement stone containing different sodium chloride (NaCl) have been investigated. Uni-axial compression experiments were used to study mechanical properties. The main crystalline phase composition of cement specimens was determined by means of X-ray diffraction (XRD). Surface morphology of cement stone was observed by using scanning electron microscopy (SEM). The obtained results showed that compared with the other samples, the sample incorporated 14% sodium chloride was quite different, whose compressive strength was higher and microstructure was denser. The sodium chloride crystalline phase and the hydration (C-S-H) gel phase co-existed.

Study on the Preparation and Properties of Piezoelectric Glass-Ceramic Sr0.5Ba0.5Nb2O6

2013 ◽  
Vol 669 ◽  
pp. 204-207
Author(s):  
Shan Jiang ◽  
Jing Wen Lv ◽  
Tao Zheng
Keyword(s):  
Particle Size ◽  
Glass Ceramic ◽  
Crystalline Phase ◽  
Room Temperature ◽  
Glass Ceramics ◽  
Molar Ratio ◽  
Spectral Transmittance ◽  
Melting Method ◽  
Ceramic Samples ◽  
Analytical Reagents

Series of ferroelectric glass-ceramic samples of Sr0.5Ba0.5Nb2O6 were synthesized by melting method. Firstly, analytical reagents were melted for 30 minutes at 1440°C after being grinded evenly according to a certain molar ratio, then annealed for 10 hours from 550°C to room temperature, finally it was sustained for 4 hours at constant temperature about 700°C. The hardness and transmittance parameters of SBN glass-ceramic were tested. Results indicated the sample had the best property when the amount of Nb2O5 was 10mol%, whose hardness reached 506 kg/mm2, and spectral transmittance was higher than 35% . XRD spectra of this sample indicated this SBN glass-ceramics contained a large number of Sr0.5Ba0.5Nb2O6 crystalline phase and a small amount of Sr0.3Ba0.7Nb2O6 phase. The particle size was about 50 nm.

Improvement of the Mechanical Properties of Glasses Based on the 3CaO.P2O5-SiO2-MgO System after Heat-Treatment

2010 ◽  
Vol 636-637 ◽  
pp. 41-46 ◽  
Author(s):  
J.K.M.F. Daguano ◽  
Claudinei dos Santos ◽  
Paulo Atsushi Suzuki ◽  
Luiz A. Bicalho ◽  
Maria Helena F.V. Fernandes
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Phase Content ◽  
Heat Treated ◽  
Different Temperatures ◽  
Hardness Values ◽  
Crystallization Degree ◽  
Temperature Crystallization

Glasses based on the 3CaO.P2O5-SiO2-MgO system present high bioactivity aiming the use as bone restorations. On the other hand, the low mechanical properties reduce the importance of this glass aiming the use as restoration bulk specimens. In this work, glass-ceramics were obtained by devitrification of this glass using different temperatures. CaCO3, SiO2, MgO and Ca(H2PO4).H2O were used as starting-powders. Powder mixture was milled/homogenized and melted at 1600°C, for 2h and annealed at 700°C for 4h with cooling rate of 3°C/min. Glass specimens of 151550mm3 were characterized by DTA and XRD analysis. Specimens were heat-treated in different temperatures between 7000C and 1050°C, for 4 hours, obtaining glass-ceramics with different crystallized phase content. Hardness and fracture toughness were determined and correlated with crystalline phase content. The results indicated that crystallization-degree increase with the temperature, and the mechanical properties are improved: Hardness values present increases lower than 20% as function of the crystallization. Fracture toughness may increase 100% as function of temperature (crystallization degree).

scholarly journals Augite-anorthite glass-ceramics from residues of basalt quarry and ceramic wastes

2015 ◽  
Vol 9 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Gamal Khater ◽  
Safiah Abu ◽  
Esmat Hamzawy
Keyword(s):  
Thermal Expansion ◽  
Glass Ceramic ◽  
Crystallization Process ◽  
Coefficient Of Thermal Expansion ◽  
Glass Ceramics ◽  
Ceramic Samples ◽  
Heat Treated ◽  
Prepared Glass ◽  
Higher Temperature ◽  
Dominant Phase

Dark brown glasses were prepared from residues of basalt quarries and wastes of ceramic factories. Addition of CaF2, Cr2O3 and their mixture CaF2-Cr2O3 were used as nucleation catalysts. Generally, structures with augite and anorthite as major phases and small amount of magnetite and olivine phases were developed through the crystallization process. In the samples heat treated at 900?C the dominant phase is augite, whereas the content of anorthite usually overcomes the augite at higher temperature (1100?C). Fine to medium homogenous microstructures were detected in the prepared glass-ceramic samples. The coefficient of thermal expansion and microhardnessmeasurements of the glass-ceramic samples were from 6.16?10-6 to 8.96?10-6?C-1 (in the 20-500?C) and 5.58 to 7.16GP, respectively.

Sign in / Sign up

Export Citation Format

Share Document