scholarly journals Crystallization and thermo-mechanical properties of Li2O-ZnO-CaO-SiO2 glass-ceramics with In2O3 and Fe2O3 additives

2015 ◽  
Vol 9 (4) ◽  
pp. 215-223 ◽  
Author(s):  
Saad Salman ◽  
Samia Salama ◽  
Ebrahim Mahdy
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Expansion Coefficient ◽  
Vickers Microhardness ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Prepared Glass ◽  
Melting Technique ◽  
Controlled Crystallization

Li2O-ZnO-CaO-SiO2 based glasses were prepared by the conventional melting technique and subsequently converted to glass-ceramics by controlled crystallization. The nucleation and crystallization temperatures were determined by differential thermal analysis (DTA). The effects of adding In2O3 and Fe2O3 addition on the crystallization behaviour and thermo-mechanical properties of the prepared glass-ceramics were investigated. A study on the microstructure, close to the internal phases of the resulting glass-ceramics, was followed by using scanning electron microscope (SEM). The dilatometric thermal expansion and Vickers? microhardness of the crystalline products were also evaluated. The crystalline phases that can be found in the resulting glass-ceramics, identified by X-ray diffraction (XRD) analysis, are ?-quartz-[SiO2], lithium zinc silicate-[Li2ZnSiO4], lithium disilicate-[Li2Si2O5], wollastonite-[CaSiO3], wollastonite containing iron, ferrobustamite-[(Ca0.79Fe0.21)SiO3], and lithium indium silicate of pyroxene type-[LiInSi2O6]. Average thermal expansion coefficient (in the temperature range 25-700?C) decreased from 191?10-7 1/?C to 115?10-7 1/?C and the Vickers? microhardness increased from 3.56 to 5.44GPa with the increase of In2O3 and Fe2O3 contents in the glass-ceramics. The changes in the obtained expansion coefficient and microhardness were due to the formation of different phases which in turn influenced the rigidity/bonding and microstructure in the resultant glass-ceramics.

Crystallization Behavior and Performance of MgO-Al2O3-SiO2 Glass-Ceramics by Sintering

2010 ◽  
Vol 92 ◽  
pp. 65-71 ◽  
Author(s):  
Pei Xin Zhang ◽  
Li Gao ◽  
Qiu Hua Yuan ◽  
Hai Lin Peng ◽  
Xiang Zhong Ren ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Crystallization Process ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Low Thermal Expansion ◽  
Main Crystalline Phase ◽  
And Performance

The glass-ceramics of MgO-Al2O3-SiO2 system were prepared by sintering technology. The crystallization process of MgO-Al2O3-SiO2 glass-ceramics was investigated with X-ray diffraction (XRD), scanning electron microscopy (SEM), and other techniques; the discussion of breaking strength, thermal expansion coefficient and relevant properties at different sintering temperatures was also presented. The results show that: (1) The main crystalline phase isα-cordierite at different sintering temperatures, and the samples show high flexural strength and low thermal expansion coefficient; (2) with the increase of sintering temperature, the content of crystal phase increases, while the thermal expansion coefficient decreases evidently, the flexural strength and tightness density rise up first, then go down.

Zn2+- Controlled Crystallization and Microstructure in K-Li-Mg-B-Si-Al-F Glass

MRS Advances ◽  
2018 ◽  
Vol 3 (60) ◽  
pp. 3525-3533 ◽  
Author(s):  
Mrinmoy Garai ◽  
Anoop K. Maurya ◽  
Shibayan Roy
Keyword(s):  
Heat Treatment ◽  
Thermal Expansion ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Ceramic ◽  
Vickers Microhardness ◽  
Glass Ceramics ◽  
Network Modifier ◽  
Base Glass ◽  
Controlled Crystallization

Abstract Text:The crystallization of (9-X) K2O-1Li2O-12MgO-10B2O3-40SiO2-16Al2O3-12MgF2-X PbO/BaO/ZnO (X =0/5) composition (wt.%) were studied by means of dilatometry, DSC, XRD, SEM and microhardness analysis. Density of base K-Li-Mg-B-Si-Al-F glass (2.59 g.cm–3) is found to be increased on addition of the network modifier oxides PbO, BaO and ZnO content. Addition of Pb2+, Ba2+ and Zn2+ furthermore increased the glass transition temperature (Tg.). A characteristic exothermic hump is found to be appeared in DSC thermograph at the temperature range 800-950°C; and that is ascribed to the formation of crystalline phase fluorophlogopite mica, KMg3(AlSi3O10)F2. Opaque glass-ceramics were prepared from K-Li-Mg-B-Si-Al-F glasses (with and without containing PbO, BaO and ZnO content) by controlled heat-treatment at 1000°C. Interlocked type microstructure combined of flake like fluorophlogopite mica crystals is obtained in ZnO-containing K-Li-Mg-B-Si-Al-F glass-ceramic; and such microstructural pattern is ascribed to cause large thermal-expansion (>11.5×10-6/K, 50-800°C).Vickers Microhardness of base glass-ceramic (5.12 GPa) is increased when contains ZnO (5.26 GPa). ZnO-containing boroaluminosilicate glass-ceramic is, hence, considered with potential interest as they can exhibit the microcrack resistivity in high temperature recycling operation (like SOFC).

Synthesis of Bio-Glass Ceramics in Na2O-CaO-SiO2-P2O5 System with Fluoride Additives

2007 ◽  
Vol 124-126 ◽  
pp. 759-762 ◽  
Author(s):  
Sung Hwan Kim ◽  
Yae Sol Kim ◽  
Hee Gon Bang ◽  
Sang Yeup Park
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
Glass Composition ◽  
Glass Ceramics ◽  
Ceramic Composition

In this study, we intend to synthesize the new bio-glass composition with fluoride additions, such as CaF2 and MgF2, instead of Na2O in bio-glass ceramic composition based on 45S5 (46.1SiO2-26.9CaO-24.4Na2O-2.6P2O5, mol%). Also, we intend to increase the SiO2 content up to 50 mol% to enhance the mechanical properties. When B2O3 (4 mol%) was added as a Na2O substitution, thermal expansion coefficient was decreased at the sintering temperature (650~950 oC). Compared to the low flexural strength (57±3 MPa) and vickers hardness (4.6 GPa) of sintered bio-glass ceramics without fluoride and B2O3, bio-glass ceramics substituted with 10mol% MgF2 for Na2O showed more higher mechanical properties (flexural strength: 141±5 MPa, vickers hardness: 5.6 GPa). Thermal expansion coefficient of bio-glass ceramics with the ion substitutions (Ca2+, Mg2+ and B3+) was decreased from 16×10-6/oC to 9.4~10×10-6/oC (~400 oC).

Preparation and Thermal Properties of P2O5 Doped Li2O-Al2O3-SiO2 Glass-Ceramics

2010 ◽  
Vol 146-147 ◽  
pp. 1574-1577
Author(s):  
Zhuo Hao Xiao ◽  
Jian Er Zhou ◽  
Wen Yan Luo
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Melting Temperature ◽  
Expansion Coefficient ◽  
Glass Ceramic ◽  
Characteristic Temperature ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Matrix Glass ◽  
Nucleation Agent

Using TiO2 and ZrO2 as compound nucleation agent, serials Li2O–Al2O3–SiO2 (LAS) glasses containing different content of P2O5 were prepared by conventional melt quenching technique and subsequent converting to glass–ceramics. The influence of P2O5 content on viscosity of LAS glasses was investigated in the temperature range from the softening point to melting temperature. DSC was undertaken to analyze the change of characteristic temperature Tg, Tc and Tp. Thermal expansion coefficient (TEC) of matrix glass and glass-ceramic containing different P2O5 were measured. The results show introducing P2O5 effectively decreased the melting temperature and viscosity of LAS glasses. TECs of the matrix glass and glass-ceramic range from 4.1×10-6 °C -1 to 5.3×10-6 °C -1 and from -0.2×10-6 °C -1 to 1.2×10-6 °C -1, respectively. XRD analysis indicates that β-spodumene is the main crystalline phase in the P2O5 doped LAS glass-ceramics, resulting in the low thermal expansion coefficient of the glass-ceramics.

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.

CHARACTERIZATION OF HYDROXYAPATITE/TI6AL4V COMPOSITE POWDER UNDER VARIOUS SINTERING TEMPERATURE

2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif
Keyword(s):  
Mechanical Properties ◽  
Composite Powder ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Different Temperatures ◽  
Two Phases ◽  
Work Interaction

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 

Using Variable Temperature Powder X-ray Diffraction To Determine the Thermal Expansion Coefficient of Solid MgO

2007 ◽  
Vol 84 (5) ◽  
pp. 818 ◽  
Author(s):  
Nicholas C. Corsepius ◽  
Thomas C. DeVore ◽  
Barbara A. Reisner ◽  
Deborah L. Warnaar
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Effects of Bi2O3 Doping on the Mechanical Properties of PbO Ceramic Pellets Used in Lead-Cooled Fast Reactors

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1948 ◽  
Author(s):  
Yan Ma ◽  
Anxia Yang ◽  
Huiping Zhu ◽  
Arslan Muhammad ◽  
Pengwei Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Eutectic Alloy ◽  
Composite Ceramic ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Oxygen Control ◽  
Fast Reactors ◽  
Future Studies ◽  
X Ray ◽  
Lead Bismuth Eutectic

In this paper, the effects of Bi2O3 doping on the mechanical properties of PbO ceramic pellets were studied. Different ratios of Bi2O3/PbO (i.e., xBi2O3-(1−x) PbO, where x is 0, 1, 3, 5, or 7 wt.%) were fabricated and sintered at 570, 620, and 670 °C. Mechanical properties including density, hardness, flexural strength, and sintering of PbO were studied for each of the aforementioned compositions. Phase composition, microstructure, and the worn surfaces of the composites were characterized by scanning electron microscopy and X-ray diffraction (XRD). The XRD analysis revealed that a solid solution formed in the composite ceramic. The best suited conditions of temperature and doping of Bi2O3 for optimal sintering were found to be 620 °C and 3 wt.%, respectively. The hardness of the 3 wt.% Bi2O3-97 wt.% PbO ceramic was found to be 717 MPa, which is about four times higher than the hardness of pure PbO. In addition, the strength of the composites was found to be 43 MPa, which is two times higher than that of pure PbO. The integrity of the composites was verified using the lead–bismuth eutectic alloy flushing experiment. The results of this research paper are important for future studies of oxygen control in the lead–bismuth eutectic alloy of lead-cooled fast reactors.

scholarly journals Measurement of Mechanical and Thermal Strains by Optical FBG Sensors Embedded in CFRP Rod

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Keunhee Cho ◽  
Sung Tae Kim ◽  
Young-Hwan Park ◽  
Jeong-Rae Cho
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Strain Sensor ◽  
Thermal And Mechanical Properties ◽  
Fbg Sensor ◽  
Thermal Test ◽  
Fbg Sensors ◽  
Thermooptic Coefficient

The present study intends to provide the photoelastic coefficient and thermal expansion coefficient needed to use an FBG-embedded CFRP rod (smart rod) as strain sensor. Due to the monolithic combination of the FBG sensor with a CFRP rod, the smart rod is likely to exhibit thermal and mechanical properties differing from those of the bare FBG sensor. A tensile test showed that the photoelastic coefficient of the smart rod is 0.204, which is about 7.3% lower than the 0.22 value of the bare optical FBG. Moreover, the thermal expansion coefficient of the smart rod obtained through a thermal test appeared to be negative with a low value of −0.190×10−6/°C. Consequently, the temperature dependence of the smart rod is mainly expressed by means of the thermooptic coefficient. Compared to the bare FBG sensor, the smart rod is easier to handle and can measure compressive strains, which make it a convenient sensor for various concrete structures.

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