Effect of Sintering Process on Microstructure of Al2O3/LiTaO3 Composite Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 2363-2365
Author(s):  
You Feng Zhang ◽  
Yu Zhou ◽  
De Chang Jia ◽  
Qing Chang Meng
Keyword(s):  
Grain Boundaries ◽  
Relative Density ◽  
Theoretical Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Hot Press ◽  
Composite Ceramics ◽  
Fine Grained ◽  
N2 Atmosphere ◽  
Hot Press Sintering

Effects of different sintering methods such as pressureless sintering and hot press sintering on relative density and microstructure of the Al2O3p/LiTaO3 (ALT) composite ceramics were investigated to obtain a preferable sintering process. Relative densities of all ALT composites are below 90% when sintered with the cold isostatical pressing followed by pressureless sintering at temperatures of 1250 to 1350°C. The relative densities and microstructure of ALT composite ceramics with the hot press sintering process in a N2 atmosphere at 1150 and 1300°C were investigated. The relative density of ALT composite hot pressed at 1150°C is only 77%, and almost theoretical density at 1300°C. This indicates that sintering pressure plays an important role in the densification of ALT composite ceramics in temperature range of 1150 to 1350°C. Investigation on morphologies of the composites shows that the Al2O3 particles distributed along grain boundaries of LiTaO3, which leads to a fine-grained microstructure in the ALT composite ceramics

Fabrication of High Density Y2O3 Ceramics by Magnetic Pulsed Compaction

2007 ◽  
Vol 119 ◽  
pp. 175-178 ◽  
Author(s):  
Jong Keuk Lee ◽  
Sung Jei Hong ◽  
Min Ku Lee ◽  
Jung G. Lee ◽  
Chang Kyu Rhee ◽  
...  
Keyword(s):  
High Pressure ◽  
Relative Density ◽  
Short Duration ◽  
High Speed ◽  
High Density ◽  
Theoretical Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Ceramic Binder

Highly dense Y2O3 ceramics have been fabricated by a magnetic pulsed compaction (MPC) which is capable of reaching a sufficiently high pressure (~1GPa) in a very short duration (a few microseconds), and a subsequent pressureless sintering at 1600°C. The Y2O3 green bodies with a relative density of about 68% were achieved by the application of the MPC process due to the effect of an enhanced rearrangement and a high speed movement of the particles, without the help of ceramic binder. Those compacts showed densities greater than 95%, which is very close to the theoretical density, after the subsequent pressureless sintering process at 1600 oC. The shrinkage rates of the diameter for the samples compacted by the MPC process were markedly reduced, when compared to those for the ones by the conventional compaction (CC) process.

Preparation of Bi3.6Ho0.4Ti3O12 Ceramics by Hot-Press Sintering

2012 ◽  
Vol 508 ◽  
pp. 253-256
Author(s):  
Chuan Bin Wang ◽  
L. Fu ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Solid State ◽  
Relative Density ◽  
Solid State Reaction ◽  
Applied Pressure ◽  
Pressureless Sintering ◽  
Hot Press ◽  
Phase Density ◽  
Densification Temperature ◽  
Hot Press Sintering ◽  
Calcined Temperature

Hot-Press Sintering, a Method that Could Effectively Decrease the Densification Temperature due to the Applied Pressure, Was Employed to Prepare a New Kind of Ho3+ Doped Bi4Ti3O12 Ceramics, Bi3.6Ho0.4Ti3O12. The Effect of Preparation Parameters on the Crystal Phase, Density and Microstructure of the Ceramics Were Investigated. at First, Single-Phased Bi3.6Ho0.4Ti3O12 Powders Were Synthesized from Bi2o3, Tio2 and Ho2o3 Raw Powders by Solid-State Reaction and the Optimum Calcined Temperature Should Be 900 °C. The as-Synthesized Powders Were Further Densified at 750-900 °C to Prepare Bi3.6Ho0.4Ti3O12 Ceramics. Dense (relative Density Was 99.4 %) Bi3.6Ho0.4Ti3O12 Ceramics with a Compact Texture Were then Obtained by Hot-Press at 850 °C, about 150-200 °C Lower as Compared with Pressureless Sintering.

Consolidation and Properties of Tungsten Carbide Target with Low Cobalt Content by Hot-Press Sintering

2007 ◽  
Vol 351 ◽  
pp. 98-102
Author(s):  
Gang Qin Shao ◽  
Z. Xiong ◽  
T.G. Wang ◽  
Xiao Liang Shi ◽  
Xing Long Duan
Keyword(s):  
Tungsten Carbide ◽  
Relative Density ◽  
Diffusion Rate ◽  
Cobalt Content ◽  
Sintering Process ◽  
Hot Press ◽  
In Situ Reaction ◽  
High Relative Density ◽  
Hot Press Sintering

Tungsten carbide (WC) targets with low cobalt (Co) content (0.1 - 0.2 wt.%) were prepared by hot-press sintering at 1700°C for 60 minutes in argon, from element starting powders of tungsten, cobalt and carbon. Results show that the as-fabricated targets yield relatively high relative density above 99% and high HRA above 92. WC with low Co content is formed easily than pure WC. The hot-press sintering process, while element starting powders are used, is an in-situ reaction technique for accelerating the WC’s diffusion rate to obtain a dense sintered body.

scholarly journals Microstructural Evolution of H-BN Matrix Composite Ceramics With Amorphous La2O3-Al2O3-SiO2 Glass Phase During Hot Pressing

2020 ◽  
Author(s):  
Baofu Qiu ◽  
Xiaoming Duan ◽  
Zhuo Zhang ◽  
Chen Zhao ◽  
Bo Niu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructural Evolution ◽  
Glass Phase ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Sintering Process ◽  
Hot Press ◽  
Composite Ceramics ◽  
Phase Precipitation ◽  
Hot Press Sintering

Abstract BN-La2O3-Al2O3-SiO2 composite ceramics were fabricated by hot press sintering using h-BN, La2O3, Al2O3 and amorphous SiO2 as the raw materials. The effects of sintering temperature on the microstructural evolution, bulk density, apparent porosity, and mechanical properties of h-BN composite ceramics were investigated. The results indicated that ternary La2O3-Al2O3-SiO2 liquid phase was formed during sintering process, which provided an environment for the growth of h-BN grains. With increasing sintering temperature, the cristobalite phase precipitation and h-BN grain growth occurred at the same time, which had the significant influence on the densification and mechanical properties of h-BN composite ceramics. The best mechanical properties of BN-La2O3-Al2O3-SiO2 composite ceramics were obtained under sintering temperature of 1700 °C, and the elastic modulus, flexural strength, and fracture toughness were 80.5 GPa, 266.4 MPa and 3.25 MPa·m1/2, respectively.

scholarly journals Remarkable plasma-resistance performance by nanocrystalline Y2O3·MgO composite ceramics for semiconductor industry applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hyeon-Myeong Oh ◽  
Young-Jo Park ◽  
Ha-Neul Kim ◽  
Kundan Kumar ◽  
Jae-Woong Ko ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Semiconductor Industry ◽  
High Plasma ◽  
Hot Press ◽  
Composite Ceramics ◽  
Plasma Resistance ◽  
Industry Applications ◽  
Hot Press Sintering ◽  
Resistance Performance ◽  
First Time

AbstractMotivated by recent finding of crystallographic-orientation-dependent etching behavior of sintered ceramics, the plasma resistance of nanocrystalline Y2O3-MgO composite ceramics (YM) was evaluated for the first time. We report a remarkably high plasma etching resistance of nanostructure YM surpassing the plasma resistance of commercially used transparent Y2O3 and MgAl2O4 ceramics. The pore-free YM ceramic with grain sizes of several hundred nm was fabricated by hot press sintering, enabling theoretical maximum densification at low temperature. The insoluble two components effectively suppressed the grain growth by mutual pinning. The engineering implication of the developed YM nanocomposite imparts enhanced mechanical reliability, better cost effectiveness with excellent plasma resistance property over their counterparts in plasma using semiconductor applications.

scholarly journals Improvement of mechanical properties of HfB2-based composites by incorporating in situ SiC reinforcement through pressureless sintering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Ghadami ◽  
E. Taheri-Nassaj ◽  
H. R. Baharvandi ◽  
F. Ghadami
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Relative Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Vacuum Atmosphere ◽  
Sic Reinforcement ◽  
Microstructural Studies ◽  
Composite Samples

AbstractHfB2, Si, and activated carbon powders were selected to fabricate 0–30 vol% SiC reinforced HfB2-based composite. Pressureless sintering process was performed at 2050 °C for 4 h under a vacuum atmosphere. Microstructural studies revealed that in situ SiC reinforcement was formed and distributed in the composite according to the following reaction: Si + C = SiC. A maximum relative density of 98% was measured for the 20 vol% SiC containing HfB2 composite. Mechanical investigations showed that the hardness and the fracture toughness of these composites were increased and reached up to 21.2 GPa for HfB2-30 vol% SiC and 4.9 MPa.m1/2 for HfB2-20 vol% SiC, respectively. Results showed that alpha-SiC reinforcements were created jagged, irregular, and elongated in shape which were in situ formed between HfB2 grains and filled the porosities. Formation of alpha-SiC contributed to improving the relative density and mechanical properties of the composite samples. By increasing SiC content, an enhanced trend of thermal conductivity was observed as well as a reduced trend for electrical conductivity.

Effects of MgO and Y2O3 on the Microstructure and Mechanical Properties of Al2O3 Ceramics

2013 ◽  
Vol 589-590 ◽  
pp. 572-577 ◽  
Author(s):  
Hua He Liu ◽  
Han Lian Liu ◽  
Chuan Zhen Huang ◽  
Bin Zou ◽  
Ya Cong Chai
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Hot Press ◽  
Composite Ceramics ◽  
Microstructure And Mechanical Properties ◽  
Suitable Amount ◽  
Hot Press Sintering ◽  
Grains Refinement ◽  
Better Than

Al2O3-MgO, Al2O3-Y2O3 and Al2O3-MgO-Y2O3 composite ceramics were fabricated respectively by hot-press sintering technique. With the analysis of the mechanical properties and microstructure, it was found that single additive MgO could be more favorable to the grains’ refinement and densification than Y2O3; the composite additive including both MgO and Y2O3 was better than single additive MgO or Y2O3, because their interactions could improve the mechanical properties of the Al2O3 ceramics; The sintering temperature could be reduced by adding the suitable amount of composite additives.

Effect of Iron Additive on the Sintering Behavior of Hot-Pressed ZrC-W Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1764-1766 ◽  
Author(s):  
Yu Jin Wang ◽  
Lei Chen ◽  
Tai Quan Zhang ◽  
Yu Zhou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Hot Press ◽  
Sintering Additive ◽  
Microstructure And Mechanical Properties ◽  
Hot Press Sintering

The ZrC-W composites with iron as sintering additive were fabricated by hot-press sintering. The densification, microstructure and mechanical properties of the composites were investigated. The incorporation of Fe beneficially promotes the densification of ZrC-W composites. The relative density of the composite sintered at 1900°C can attain 95.3%. W2C phase is also found in the ZrC-W composite sintered at 1700°C. The content of W2C decreases with the increase of sintering temperature. However, W2C phase is not identified in the composite sintered at 1900°C. The flexural strength and fracture toughness of the composites are strongly dependent on sintering temperature. The flexural strength and fracture toughness of ZrC-W composite sintered at optimized temperature of 1800°C are 438 MPa and 3.99 MPa·m1/2, respectively.

Sintering of β-Si3N4 Powder Prepared by Self-Propagating High-Temperature Synthesis (SHS)

2007 ◽  
Vol 546-549 ◽  
pp. 2179-2182 ◽  
Author(s):  
Ling Bai ◽  
Xing Yu Zhao ◽  
Chang Chun Ge
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Bending Strength ◽  
Sintering Process ◽  
Hot Press ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Good Sinter ◽  
The Cost ◽  
Hot Press Sintering

Sintering of the Self-Propagating High-Temperature Synthesis (SHS) of β-Si3N4 powder with 6.67 wt.% Y2O3 and 3.33 wt.% Al2O3 as sintering additives has been emphatically investigated using hot-press sintering process. The relative density of hot-pressed β-Si3N4 reached near to the full densification (99.43%) at 1700°C. The similar micrographs with self-reinforcing rod-like β-Si3N4 grains forming an interlocking structure were observed. The better mechanical properties of hot-pressed Si3N4, such as the hardness (16.73GPa), fracture toughness (5.72 MPa·m1/2) and bending strength (611.72MPa) values, were obtained at 1700°C. The results indicate that good sinter ability can be obtained with the cheaply SHS of silicon nitride powder for preparing silicon nitride materials, which will make the cost of silicon nitride materials lowered.

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