Synthesis and Sintering Comparison of Cordierite Powders

1986 ◽  
Vol 73 ◽  
Author(s):  
J. C. Bernier ◽  
J. L. Rehspringer ◽  
S. Vilminot ◽  
P. Poix
Keyword(s):  
Electronic Properties ◽  
Electronic Packaging ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Theoretical Density ◽  
Drastic Decrease ◽  
Conventional Methods ◽  
Gel Processing ◽  
Inorganic Precursors ◽  
Better Than

ABSTRACTCordierite and cordierite based glass ceramics are promising materials for electronic packaging. Preparations by organic and inorganic precursors along sol-gel processing are reported. Compared with conventional methods, they show a drastic decrease of the sintering temperatures. A process able to giving better than 95% theoretical density ceramic below 1000°C, with good electronic properties is described.

Ceramic Materials for Electronic Packaging

1989 ◽  
Vol 111 (3) ◽  
pp. 183-191 ◽  
Author(s):  
E. M. Rabinovich
Keyword(s):  
Electronic Packaging ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Packaging Materials ◽  
Ceramic Powders ◽  
Main Attention

The paper reviews ceramic materials that are used or can be used in electronic packaging. Main attention is given in relatively new packaging materials such as highly thermal conductive AlN and SiC (BeO-doped) or low-firing cordierite and spodumene glass-ceramics. Application of sol-gel processes in preparation of ceramic powders is discussed.

Environmental Effects in Gel Derived Silicates

1984 ◽  
Vol 32 ◽  
Author(s):  
L.L. Hench
Keyword(s):  
Corrosion Resistance ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Thermal Exposure ◽  
Scientific Basis ◽  
Environmental Stability ◽  
Processing Variables ◽  
End Use ◽  
The Stability ◽  
Gel Processing

Various methods have been developed for producing crystals, powders, coatings and monoliths from gels [1]. The scientific basis for understanding compositional effects, gelation, aging, drying and densification is also advancing rapidly [2]. However, there is as yet relatively little information on the durability, weathering, or corrosion resistance of glasses, glass-ceramics, ceramics, or composites made via the gel route. Data is also sparse on the effects of vacuum, thermal exposure, or mechanical stress on the stability of gel-derived solids. Relationships between sol-gel processing variables and environmental stability are especially lacking at the present time. Since many end-use applications of gel derived materials involve exposure to severe environments, it is essential that the durability of these materials be established during their development.

Gel-derived amorphous cesium-aluminosilicate powders useful for formation of pollucite glass-ceramics

1991 ◽  
Vol 6 (2) ◽  
pp. 217-219 ◽  
Author(s):  
Mari A. Hogan ◽  
Subhash H. Risbud
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Amorphous Powder ◽  
Glass Crystallization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Powders ◽  
Gel Processing ◽  
Scanning Electron

Amorphous powders in the Cs2O–Al2O3−SiO2 system were prepared by sol-gel processing. Gels made from TEOS, Al-chelate, and Cs-acetate were dried and calcined to obtain molecularly mixed powders of analyzed compositions in the range useful for conversion to pollucite (CsAlSi2O6) glass-ceramics. X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetry (TG), and scanning electron microscopy (SEM) were used to characterize the powders. A typical amorphous powder of analyzed chemical composition (in wt.%) = 28.05Cs2O, 37.77SiO2, and 37.96Al2O3 was found to have a glass transition temperature of 945 °C and a glass crystallization temperature of 1026 °C. Preliminary experimental results of densification and crystallization of the amorphous powders show pollucite/mullite phases to be present.

Sol-Gel Processing of Glasses and Glass-Ceramics for Microelectronic Packaging

1991 ◽  
Vol 249 ◽  
Author(s):  
M.A. Sriram ◽  
P.N. Kumta
Keyword(s):  
Dielectric Constant ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Signal Propagation ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
Low Dielectric ◽  
Heat Treated ◽  
Gel Processing

In recent years considerable progress has been made in electronic packaging substrate technology. The future need of miniaturization of devices to increase the signal processing speeds calls for an increase in the device density requiring the substrates to be designed for better thermal, mechanical and electrical efficiency.Fast signal propagation with minimum delay requires the substrate to possess very low dielectric constant. Several glasses and glass-ceramic materials have been identified over the years which show good promise as candidate substrate materials. Among these borophosphate and borophosphosilicate glass-ceramics have been recently identified to have the lowest dielectric constant (3.8). Sol-gel processing has been used to synthesize borosilicate, borophosphosilicate and borophosphate glasses and glass-ceramics using inexpensive boron oxide and phosphorus pentoxide precursors. Preliminary results of the processing of these gels and the effect of volatility of boron alkoxide and its modification on the gel structure are described. X-ray diffraction, Differential thermal analyses and FTIR have been used to characterize the as-prepared and heat treated gels.

Sol-gel processing in electronic packaging materials

1992 ◽  
Vol 147-148 ◽  
pp. 783-791 ◽  
Author(s):  
Shyama P. Mukherjee ◽  
D. Suryanarayana ◽  
D.H. STrope
Keyword(s):  
Electronic Packaging ◽  
Sol Gel ◽  
Packaging Materials ◽  
Gel Processing

Dielectric and structural properties of SiO2-LiFe5O8 glass–ceramics prepared by sol–gel processing

2010 ◽  
Vol 356 (11-17) ◽  
pp. 607-610 ◽  
Author(s):  
M.P.F. Graça ◽  
C.C. Silva ◽  
L.C. Costa ◽  
A.S.B. Sombra ◽  
M.A. Valente
Keyword(s):  
Structural Properties ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Gel Processing

scholarly journals To Evaluate the Application of Alkoxide Sol-Gel Method in Fabrication of 3YSZ-MWCNTs Nanocomposites, in an Attempt to Improve Its Mechanical Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Ali Ahmadi ◽  
Amir Ali Youzbashi ◽  
Ahmad Nozad Golikand ◽  
Toraj Ebadzadeh ◽  
Amir Maghsoudipour
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Composite System ◽  
Sol Gel ◽  
Research Work ◽  
Nanocomposite Powder ◽  
Good Adhesion ◽  
The Matrix ◽  
Gel Processing ◽  
Inorganic Precursors

In the present research work, fabrication of YSZ-CNTs composite system through alkoxide sol-gel processing was evaluated, in an attempt to improve its mechanical properties. Nanocomposites containing 0.5–2 wt% MWCNTs were then fabricated through the hydrolysis and condensation processing of the solution mixtures containing alkoxide and inorganic precursors along with the functionalized CNTs under basic condition and its final sintering by the SPS technique at 1400°C. Results showed the formation of a nanocomposite powder based on pure 3YSZ matrix, with well dispersion of CNTs and its good adhesion to the matrix particles in composite containing 0.5 wt% CNTs. The fracture toughness of sintered samples showed around 24% increase for the composite containing 0.5 wt% CNTs. The fracture toughness, hardness, and density decreased due to the agglomeration of CNTs over 0.5 wt%. Toughening mechanisms including pullout and crack bridging were observed on the polished and fractured surfaces.

scholarly journals Hydrolytic Modification of SiO2 Microspheres with Na2SiO3 and the Performance of Supported Nano-TiO2 Composite Photocatalyst

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2553
Author(s):  
Yu Tu ◽  
Weihua Ao ◽  
Chunhong Wang ◽  
Tianyu Ren ◽  
Lijuan Zhang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Active Surface ◽  
Hydroxyl Groups ◽  
Nano Tio2 ◽  
Amorphous Sio2 ◽  
Composite Photocatalyst ◽  
Sio2 Shell ◽  
Functional Efficiency ◽  
Sio2 Microspheres ◽  
Better Than

Modified microspheres (SiO2-M) were obtained by the hydrolytic modification of silicon dioxide (SiO2) microspheres with Na2SiO3, and then, SiO2-M was used as a carrier to prepare a composite photocatalyst (SiO2-M/TiO2) using the sol-gel method; i.e., nano-TiO2 was loaded on the surface of SiO2-M. The structure, morphology, and photocatalytic properties of SiO2-M/TiO2 were investigated. Besides, the mechanism of the effect of SiO2-M was also explored. The results show that the hydrolytic modification of Na2SiO3 coated the surface of SiO2 microspheres with an amorphous SiO2 shell layer and increased the quantity of hydroxyl groups. The photocatalytic performance of the composite photocatalyst was slightly better than that of pure nano-TiO2 and significantly better than that of the composite photocatalyst supported by unmodified SiO2. Thus, increasing the loading capacity of nano-TiO2, improving the dispersion of TiO2, and increasing the active surface sites are essential factors for improving the functional efficiency of nano-TiO2. This work provides a new concept for the design of composite photocatalysts by optimizing the performance of the carrier.

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