Effect of Aluminium Powder on the Hot Mechanical Properties of Corundum-Silicon Nitride Composites

2011 ◽  
Vol 189-193 ◽  
pp. 3960-3963
Author(s):  
Jun Cong Wei ◽  
Jun Bo Tu
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Silicon Nitride ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Modulus Of Rupture ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Aluminium Powder ◽  
Air Atmosphere

Based on the Al-O-N phase stable diagram and adopting inverse reaction sintering process, corundum-silicon nitride composite refractories were prepared using corundum, silicon nitride, clay and aluminium powder as the main starting materials. The specimens were sintered at 1600 for 3 hours under air atmosphere with different oxygen partial pressure obtained by addition of different amount of aluminium powder. The effects of aluminium powder additions(0, 4wt.%, 8 wt.% and 12 wt.% respectively) on the hot modulus of rupture were investigated .The phase composition and microstructure were tested by means of XRD, SEM and EDAS.The results showed that aluminium would be oxidized, nitrided and displaced as aluminium powder increased during sintering, which reduced the oxygen partial pressure in the specimen. The hot modulus of rupture (HMOR) increased considerably due to large amounts of fibrous sialon formed.

Recrystallization of Oxygen Contaminated Al Films

1986 ◽  
Vol 71 ◽  
Author(s):  
G.J. Van Der Kolk ◽  
M.J. Verkerk
Keyword(s):  
Grain Size ◽  
Silicon Nitride ◽  
Substrate Temperature ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Relative Increase ◽  
Partial Pressures ◽  
Average Grain Size

AbstractAl was evaporated at oxygen partial pressures, PO2, varying between 10−7 and 10−4 Pa on substrates of silicon nitride. The substrate temperature was varied between 20 °C and 250°C. The films were annealed at temperatures up to 500°C.For Al films deposited at 20°C, it was found that the average grain size decreases with increasing oxygen partial pressure. After annealing recrystallization was observed. The relative increase of grain size was less for higher values of pO2. Annealing gave rise to a broad grain size distribution.For Al films deposited at 250°C, the presence of oxygen caused the growth of rough inhomogeneous films. This inhomogeneous structure remained during annealing.

scholarly journals Effects of Sintering Behaviors on Dimensional Accuracy, Surface Quality, and Mechanical Properties of Stereolithography-printed 3Y-ZrO2 Ceramics

2021 ◽  
Author(s):  
Cheng Zhang ◽  
Zhaoliang Jiang ◽  
Li Zhao ◽  
Weiwei Guo ◽  
Chengpeng Zhang
Keyword(s):  
Mechanical Properties ◽  
Dental Implants ◽  
Surface Quality ◽  
Dimensional Accuracy ◽  
Scanning Speed ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Air Atmosphere ◽  
Length Width ◽  
Technical Guide

Abstract Sintering process is essential to acquire the final components by stereolithography (SLA), which is a promising additive manufacturing technology for the fabrication of complex, custom-designed dental implants. 3Y-ZrO2 ceramics at different sintering behaviors in air atmosphere were successfully obtained in this study. Firstly, the curing properties of homemade pastes were studied, and the penetration depth and critical exposure of the pastes were calculated as 17.2 μm and 4.80 mJ/cm2, respectively. The green ceramic parts were performed at 154 mW laser power and 6000 mm/s scanning speed. Then, the dimensional accuracy, surface quality, and mechanical properties of 3Y-ZrO2 ceramics were investigated. The shrinkages of length, width, and height were 26%~27 %, 30%~31 %, and 27%~33 % in sintered ceramics, respectively. The Ra values of XOY, YOZ, and XOZ surfaces showed an anisotropic feature, and they were smallest as 0.52 μm, 2.40 μm, and 2.46 μm, respectively. Meanwhile, the mechanical properties presented a similar trend that they grew first and then dropped at various sintering behaviors. The optimal parameters were 1500 ℃, 60 min, and 4 ℃/min, and the maximum relative density of 96.18 %, Vickers hardness of 12.45 GPa, and fracture toughness of 6.35 MPa·m1/2 were achieved. Finally, the X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) analysis demonstrated that no change was observed in crystal transformation and phase composition, and the organic was completely removed in sintered ceramics. This research is expected to provide a technical guide for the fabrication of ceramics for dental implants using SLA technique.

Development of High Performance Silicon Nitride Ceramics and their Applications

1992 ◽  
Vol 287 ◽  
Author(s):  
Yo Tajima
Keyword(s):  
Mechanical Properties ◽  
Silicon Nitride ◽  
High Performance ◽  
Future Prospect ◽  
Cutting Tools ◽  
Sintering Process ◽  
Sintering Additives ◽  
Nitride Ceramics ◽  
Engine Components

ABSTRACTProgress in sintering process and improvement of mechanical properties of silicon nitride ceramics are reviewed. Emphases are placed on contributions of advanced sintering techniques and better understanding of sintering additives and microstructure-properties relations. Current applications as engine components and cutting tools are described, and future prospect is considered.

scholarly journals Influence of MXene (Ti3C2) Phase Addition on the Microstructure and Mechanical Properties of Silicon Nitride Ceramics

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5221
Author(s):  
Jaroslaw Wozniak ◽  
Mateusz Petrus ◽  
Tomasz Cygan ◽  
Artur Lachowski ◽  
Bogusława Adamczyk-Cieślak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Silicon Nitride ◽  
Powder Processing ◽  
Sintering Process ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Nitride Ceramics ◽  
Spark Plasma

This paper discusses the influence of Ti3C2 (MXene) addition on silicon nitride and its impact on the microstructure and mechanical properties of the latter. Composites were prepared through powder processing and sintered using the spark plasma sintering (SPS) technic. Relative density, hardness and fracture toughness, were analyzed. The highest fracture toughness at 5.3 MPa·m1/2 and the highest hardness at HV5 2217 were achieved for 0.7 and 2 wt.% Ti3C2, respectively. Moreover, the formation of the Si2N2O phase was observed as a result of both the MXene addition and the preservation of the α-Si3N4→β-Si3N4 phase transformation during the sintering process.

scholarly journals The Influence of Thermal Residual Stresses on Mechanical Properties of Silicon Nitride-Based Composites

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1092
Author(s):  
Aleksandra Dubiel ◽  
Grzegorz Grabowski ◽  
Marcin Goły ◽  
Stanisław Skrzypek
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Phase Composition ◽  
Silicon Nitride ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Thermal Residual Stresses ◽  
Microstructure Parameters ◽  
Xrd Method

In this work, two kinds of silicon nitride-based composites, namely, those with titanium nitride or silicon carbide additives, were sintered using the hot pressing technique (HP). The phase composition, microstructure, and mechanical and elastic properties of the materials were characterized. Three-dimensional geometric models of the composites were created on the basis of microstructure parameters. Using these models, bulk residual thermal stresses were calculated by the finite element method (FEM). Surface stresses were determined using the XRD method of sin2ψ.

1303 Crack-healing behavior of silicon nitride/silicon carbide composite at low oxygen partial pressure

2008 ◽  
Vol 2008.6 (0) ◽  
pp. 343-344
Author(s):  
Young-Soon JUNG ◽  
Wataru NAKAO ◽  
Koji TAKAHASHI ◽  
Kotoji ANDO ◽  
Sinji SAITO
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Crack Healing ◽  
Low Oxygen ◽  
Carbide Composite

Influences of Temperature and Oxygen Partial Pressure on Mechanical Properties of La0.6Sr0.4Co1−yFeyO3−δ

2012 ◽  
Vol 95 (8) ◽  
pp. 2608-2613 ◽  
Author(s):  
Yuta Kimura ◽  
Takuto Kushi ◽  
Shin-ichi Hashimoto ◽  
Koji Amezawa ◽  
Tatsuya Kawada
Keyword(s):  
Mechanical Properties ◽  
Oxygen Partial Pressure ◽  
Partial Pressure

The Effects of Oxygen Vacancy Concentration on the Mechanical Properties of Zirconia and Ceria-Based Electrolytes for SOFCs

2009 ◽  
Author(s):  
Toshiyuki Hashida ◽  
Yohei Takeyama ◽  
Kazuhisa Sato
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Fracture Surface ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Fracture Strength ◽  
Atmospheric Pressure ◽  
Small Punch ◽  
Testing Method ◽  
Partial Pressures

In this paper, we discuss the effects of different oxygen partial pressures on the deformation property and fracture characteristics of representative constituent materials for solid oxide fuel cells (SOFCs). The elastic modulus and fracture strength of 8 mol% yittria stabilized zirconia (8YSZ) and 10 mol% gadolinia doped ceria (10GDC) treated under different oxygen partial pressures were evaluated using the small-punch testing method in this study. The specimens of 8YSZ and 10GDC prepared by a sintering process were treated at 800 °C under an oxygen partial pressure in the range of 0.21 to 10−22 atm for 1 hour. The treated specimens were then fast cooled down to a room temperature, and their mechanical properties were measured under an atmospheric pressure condition by using the small-punch testing method. The experimental results revealed that both the elastic modulus and fracture strength of the 10GDC decreased drastically when the oxygen partial pressure of the treatment was less than 10−15 atm, whereas no significant variation in both the mechanical properties was observed for the 8YSZ. The elastic modulus and fracture strength of 10GDC for the treatment under 10−22 atm was reduced down to 10–20% of those treated under the atmospheric pressure. SEM observations revealed that the fracture surface of the 10GDC specimens was changed from transgranular mode to intergranular mode when the oxygen partial pressure was reduced, whereas the fracture surface of the 8YSZ specimens was transgranular regardless of the different oxygen partial pressures.

Phase Composition, Microstructure and Mechanical Properties of Aluminous Cements Containing Magnesium Aluminate Spinel

2011 ◽  
Vol 492 ◽  
pp. 467-471
Author(s):  
Jin Hong Li ◽  
Ling Xin Tong ◽  
Wen Cai Zhou
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Phase Composition ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Curing Time ◽  
Sintering Process ◽  
Microstructure And Mechanical Properties ◽  
New Type ◽  
Aluminous Cement

A new type aluminous cement containing magnesium aluminate (MA) spinel was prepared from mixtures of limestone, magnesian and bauxite at different ratios by sintering process. The phase composition, microstructure and mechanical properties of aluminous cements containing magnesium aluminate spinel were investigated in this paper. According to the XRD results, the magnesium aluminate spinel (MA),calcium monoaluminate (CA) and calcium bialuminate (CA2) are the primary phases of the obtained aluminous cements with a small quantity of calcium silicoaluminate (C2AS) and remained alumina (Al2O3). The results of SEM indicate that the MA mainly exist in the shape of octahedron with the length of about 2-5 μm, and it is agglomerated with the tabular or flaky-shaped CA among the obtained aluminous cements. In addition, the compressive strength of castables containing obtained aluminous cements increase obviously with the content of CA rising or the curing time increasing.

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