Fabrication of magnetically controllable glass ceramics with completely dense microstructure by hot pressing

2021 ◽  
Author(s):  
Yong Hou ◽  
Yu Wang ◽  
Guo‐Hua Zhang ◽  
Kuo‐Chih Chou
Keyword(s):  
Hot Pressing ◽  
Glass Ceramics ◽  
Dense Microstructure

Metal Alkoxide Synthesis of Glasses and Glass-Ceramics

1985 ◽  
Vol 57 ◽  
Author(s):  
Charles H. Drummond
Keyword(s):  
Hot Pressing ◽  
Low Temperatures ◽  
Glass Formation ◽  
Glass Ceramics ◽  
Base Hydrolysis ◽  
Metal Alkoxide ◽  
Metal Alkoxides ◽  
Fine Grained ◽  
Amorphous Powders

AbstractMetal alkoxide syntheses of the general form or can be used to form soluble alkoxides of most metals. Mutual solution of these alkoxides followed by acid or base hydrolysis, drying and calcining results in the formation of fine-grained (<10Å) amorphous powders at low temperatures. Subsequent hot-pressing or calcining leads to densification and/or crystallization. Compositions in the MgO-Al2O3-SiO2 system with ZrO2 contents to 30 mol% are discussed. Also glass formation of transition oxides derived from metal alkoxides of Hf, Zr, Y and Nb in various combinations are presented.

Formability of AZ31 Alloys Prepared by Hot-Extrusion of their Machined Chips

2010 ◽  
Vol 638-642 ◽  
pp. 1569-1573
Author(s):  
Kunio Matsuzaki ◽  
Yoichi Murakoshi ◽  
Toru Shimizu ◽  
Kaoru Kikuchi
Keyword(s):  
Hot Pressing ◽  
Hot Extrusion ◽  
Az31 Alloy ◽  
Backward Extrusion ◽  
Dense Microstructure ◽  
Equiaxed Grains ◽  
Good Workability

Machined AZ31 alloy chips were consolidated by hot-pressing and then hot-extrusion at 300 °C, and their workability was evaluated. The consolidated sample has a fully dense microstructure with fine equiaxed grains. The　compression and backward extrusion tests reveal that the consolidated AZ31 chips have a good workability at above 200°C.　It is said that the recycled AZ31 alloy by hot-extrusion of the chips is suitable for forging materials and the process is useful for the recycling of Mg chips.

Highly Transparent Y-α-Sialon by Hot Pressing

2011 ◽  
Vol 148-149 ◽  
pp. 599-602
Author(s):  
Ying Chun Shan ◽  
Hui Ye ◽  
Jiu Jun Xu ◽  
Jiang Tao Li
Keyword(s):  
Hot Pressing ◽  
Single Phase ◽  
Near Infrared ◽  
Wavelength Region ◽  
High Hardness ◽  
Optical Transmittance ◽  
Nitrogen Atmosphere ◽  
Infrared Wavelength ◽  
Dense Microstructure ◽  
Equiaxed Grain

The single-phase Y-α-sialon ceramics with highly optical transmittance were produced by hot pressing starting mixtures of Si3N4, AlN, Al2O3and Y2O3at 1900 °C for 0.5 h in a nitrogen atmosphere. The resultant sialon shows very high optical transparency in the near infrared wavelength region, about 70% for 0.8 mm thickness. In addition to highly transmittance, the Y-α-sialon also show high hardness (19 GPa) and well fracture toughness (4 MPa•m1/2), which attribute to the compound microstructure of uniform, equiaxed grain with a grain size of 2 μm and small aspect ration elongated α-sialon (<2) with a length no more than 5 μm. The high transparent was attribute to the uniform dense microstructure and pure single-phase α-sialon.

Nearly zero thermal expansion of β-spodumene glass ceramics prepared by sol–gel and hot pressing method

2012 ◽  
Vol 38 (6) ◽  
pp. 5315-5318 ◽  
Author(s):  
Long Xia ◽  
Xinyu Wang ◽  
Guangwu Wen ◽  
Bo Zhong ◽  
Liang Song
Keyword(s):  
Thermal Expansion ◽  
Hot Pressing ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Pressing Method

Effect of Al2O3 on the Glass-Ceramics of CaO-SiO2-MgO-Al2O3 System Based on BOF Slag

2013 ◽  
Vol 833 ◽  
pp. 208-212
Author(s):  
Wen Bin Dai ◽  
Yu Li ◽  
Yuan Yuan Zhou ◽  
Da Qiang Cang ◽  
Yong Fan
Keyword(s):  
Flexural Strength ◽  
Waste Heat ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Slag Viscosity ◽  
Dense Microstructure ◽  
Weight Content ◽  
Bof Slag ◽  
Physical And Chemical ◽  
Sintering Shrinkage

Directly recycling residual iron element in modified BOF slag after reduction and manufacturing glass-ceramics from these remaining inorganic slag materials is an effective way to reuse the waste heat and slag materials of hot BOF slag. In the glass-ceramics, the Al2O3 has an important influence on the slag viscosity and the physical and chemical properties of glass-ceramics. In this paper, glass-ceramics with a basicity of 0.7 and a MgO content of 9~12% were prepared by using chemically pure reagents according to the CaO-SiO2-MgO phase diagram, and the effect of different Al2O3 content on the parent glass crystallization and glass-ceramic performances was studied. Results show that the flexural strength of glass-ceramics is mainly affected by the sintering shrinkage. When the weight content of Al2O3 exceeds 15%, both the flexural strength and the shrinkage rate reached the maximum, and dense microstructure was obtained. In addition, the original dominant crystal structure is affected while Al2O3>12%, with the anorthite crystal phase appearing consequently.

scholarly journals Structure and spectral properties of Fe:ZnAl2O4 transparent glass-ceramics and ceramic

2021 ◽  
Vol 2086 (1) ◽  
pp. 012138
Author(s):  
K Eremeev ◽  
L Basyrova ◽  
O Dymshits ◽  
S Balabanov ◽  
A Belyaev ◽  
...  
Keyword(s):  
Comparative Study ◽  
Raman Spectra ◽  
Hot Pressing ◽  
Spectral Properties ◽  
Glass Ceramics ◽  
Melt Quenching ◽  
Absorption Properties ◽  
Transparent Glass ◽  
Sintering Additive ◽  
C 50

Abstract Transparent glass-ceramics based on iron-doped ZnAl2O4 (gahnite) nanocrystals were prepared by melt-quenching (at 1580 °C) with subsequent heat-treatments (at 720 – 1050 °C). Polycrystalline transparent Fe:ZnAl2O4 ceramic was synthesized by hot pressing of powders (at 1600 °C, 50 MPa) using the sintering additive, ZnF2. A comparative study of the structure, Raman spectra and absorption properties of these materials was performed.

Effect of matrix crystallinity on the characteristics of the interfacial layer in SiC fiber-reinforced Si-Al-O-N composites

1992 ◽  
Vol 50 (1) ◽  
pp. 156-157
Author(s):  
Hyun-Ho Shin ◽  
Yolande Berta ◽  
Chan Park ◽  
Robert F. Speyer
Keyword(s):  
Hot Pressing ◽  
Interfacial Layer ◽  
Interfacial Shear Strength ◽  
Glass Ceramics ◽  
Interfacial Shear ◽  
New Host ◽  
Infiltration Process ◽  
Fiber Damage ◽  
Low Viscosity ◽  
Sic Fiber

Glass or glass-ceramics have been used as matrix materials for fiber reinforcing by the slurry infiltration process, followed by hot pressing. These matrices have been used for two major reasons: (i) They oxidize the SiC fiber to form a C-rich interfacial layer between the fiber and matrix during hot pressing (2SiC(s) + O2(g) = 2C(s) + 2SiO(g)). Such carbon-rich layers cause low fiber-matrix interfacial shear strength resulting in high composite fracture toughness. (ii) A low viscosity matrix is required to minimize fiber damage during hot pressing. In the present study, the Si2N2O - AI2O3 system was used as a new host material for Nicalon SiC fiber: it has a more refractory nature and is able to provide a liquid phase (with the presence of a sintering agent, e.g., A12O3, CaO, etc.) to avoid fiber damage during densification. This matrix system can also provide oxygen to form a C-rich interphase. In this paper, the effect of matrix crystallinity on the interfacial characteristics is described.

Sign in / Sign up

Export Citation Format

Share Document