Preparation and Mechanical Properties of TiN-Al2O3 Refractory Composites

2013 ◽  
Vol 833 ◽  
pp. 217-220
Author(s):  
Hai Tao Liu ◽  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Hai Peng Ji ◽  
Xin Min ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Bulk Density ◽  
Sintering Temperature ◽  
Aluminothermic Reduction ◽  
Pressureless Sintering ◽  
Densification Behaviour ◽  
Effects Of Temperature ◽  
Refractory Composites

TiN-Al2O3 bulk composites were prepared by pressureless sintering of the as-synthesized powder products obtained by aluminothermic reduction-nitridation of aluminum dross and rutile. The effects of temperature on the densification behaviour and mechanical properties of TiN-Al2O3 composites were studied. Results showed that the bulk density of the TiN-Al2O3 composites increased with the elevated sintering temperature. When the temperature arrived at 1500 °C, the flexural strength and fracture toughness reached the highest values (201.48 MPa and 4.11 MPa·m1/2, respectively).

Preparation and Mechanical Properties of ReAl11O18 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 345-348
Author(s):  
Jun Dong Zhang ◽  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
Xin Min ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Bulk Density ◽  
Room Temperature ◽  
Pressureless Sintering ◽  
Optimal Temperature ◽  
Flexure Strength ◽  
The Real

In this paper, plate-like ReAl11O18 (Re = La, Pr, Nd) toughened ceramics were prepared by pressureless sintering at 1650 °C for 5 h in air. The bulk densities of the sintered samples were between 4.7 to 5.3g/cm3. The mechanical properties of the ReAl11O18 ceramics were studied systematically at room temperature. The flexure strength and fracture toughness of ReAl11O18 ceramics were 97.5 to 102.7 Mpa and 3.8 to 4.2Mpa.m1/2. The results show that: The optimal temperature to synthesis ReAl11O18 ceramics was 1650 °C; The flexural strength and fracture toughness of the ReAl11O18 ceramics increase with the increasing of its bulk density.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

scholarly journals Microstructure and Mechanical Properties of ZrB2–HfC Ceramics Influenced by HfC Addition

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2046 ◽  
Author(s):  
Yi Jing ◽  
Hongbing Yuan ◽  
Zisheng Lian
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Grain Boundaries ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Weak Interface ◽  
Interface Bonding ◽  
Microstructure And Mechanical Properties ◽  
Small Grains

ZrB2–HfC ceramics have been fabricated using the liquid phase sintering technique at a sintering temperature as low as 1750 °C through the addition of Ni. The effects of HfC addition on the microstructure and mechanical properties of ZrB2–based ceramics have been investigated. These ceramics were composed of ZrB2, HfC, Ni, and a small amount of possible (Zr, Hf)B2 solid solution. Small HfC grains were distributed among ZrB2 grain boundaries. These small grains could improve the density of ZrB2–based ceramics and play a pinning role. With HfC content increasing from 10 wt % to 30 wt %, more HfC grains were distributed among ZrB2 grain boundaries, leading to weaker interface bonding among HfC grains; the relative density and Vickers hardness increased, and flexural strength and fracture toughness decreased. The weak interface bonding for 20 and 30 wt % HfC contents was the main cause of the decrease in both flexural strength and fracture toughness.

Effect of Y2O3 on the Sintering, Mechanical and Dielectric Properties of Mullite/h-BN Composites

2016 ◽  
Vol 848 ◽  
pp. 28-31
Author(s):  
Han Jin ◽  
Yong Feng Li ◽  
Zhong Qi Shi ◽  
Hong Yan Xia ◽  
Guan Jun Qiao
Keyword(s):  
Fracture Toughness ◽  
Dielectric Constant ◽  
Phase Composition ◽  
High Temperature ◽  
Dielectric Properties ◽  
Liquid Phase ◽  
Flexural Strength ◽  
Sintering Temperature ◽  
Pressureless Sintering ◽  
Different Temperatures

Mullite/10 wt. %h-BN composites with 5 wt. % Y2O3 additive were fabricated by pressureless sintering at different temperatures. The densification, phase composition, microstructure, mechanical and dielectric properties of the mullite/h-BN composites were investigated. With the addition of Y2O3, the sintering temperature of the mullite/h-BN composites declined, while the density, mechanical and dielectric properties all increased. The addition of Y2O3 promoted the formation of liquid phase at high temperature, which accelerated the densification. Besides, Y2O3 particles which were located at the grain boundaries inhibited the grain growth of mullite matrix. For the mullite/h-BN composites with Y2O3 additive, the appropriate sintering temperature was about 1600°C. The relative density, flexural strength, fracture toughness and dielectric constant of the Y2O3 doped mullite/h-BN composite sintered at 1600 °C reached 82%, 135 MPa, 2.3 MPa·m1/2 and 4.9, respectively.

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.

Si3N4/BN Composite Ceramics with Nd2O3-Al2O3-Y2O3 Ternary Additives by Pressureless Sintering

2010 ◽  
Vol 434-435 ◽  
pp. 106-108
Author(s):  
Ping Liu ◽  
Yong Feng Li ◽  
Xiang Dong Wang ◽  
Hai Yun Jin ◽  
Guan Jun Qiao
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Flexural Strength ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Composite Ceramics ◽  
Fracture Toughness Testing ◽  
Β Phase ◽  
Toughness Testing

Si3N4/BN composite ceramics with 25vol% h-BN were prepared by pressure-less sintering process with Nd2O3/Al2O3/Y2O3 as sintering additives. The effects of these ternary additives on the densification behaviors and mechanical properties were investigated. XRD and FESEM were used to investigate the α-β phase transformation and microstructure. The XRD results showed that α-Si3N4 has transformed to β-Si3N4 completely in all the samples during the pressureless sintering process. The line shrinkage increased with the Nd2O3 contents increasing, and the highest line shrinkage (7.75%) was observed when 4wt% Nd2O3 was added, then decreased. The same trends were observed in flexural strength and fracture toughness testing. The ternary additives of Y2O3-Al2O3-Nd2O3 could improve the density, strength and fracture toughness of the material effectively.

Microstructure and Mechanical Properties of Hot-Pressed and Pressureless Sintered WC-Al2O3 Ceramic Composites

1993 ◽  
Vol 327 ◽  
Author(s):  
Hidehiro Endo ◽  
Masanori Ueki
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Composite System ◽  
Ceramic Composites ◽  
Pressureless Sintering ◽  
Sintering Aid ◽  
Al2o3 Ceramic ◽  
Remarkable Improvement

AbstractFully densified WC-A12O3 composites were successfully consolidated by both hot-pressing and pressureless sintering. The optimum hot-pressing condition for the composites was 1700°C for 2h under a pressure of 40MPa. A remarkable improvement in mechanical properties was achieved in the composite system, especially in WC-30 and -70vol%A12O3, compared to the monolithic WC and A12O3 ceramics. The addition of MgO as a sintering aid had a great effect on the properties of the composites. WC-30vol%A12O3 composite with 1.Owt% MgO addition exhibited flexural strength higher than 1000MPa up to 1200°C, fracture toughness; KIC≥7MPa√m, and hardness; HV ≥2450. In pressureless sintering with the addition of MgO as a sintering aid and subsequent HIP treatment, the WC-30vol%A12O3 composite exhibited the flexural strength higher than 900MPa up to 1200°C.

Study of the Mechanical Properties and Toughening Mechanism of Nano-NbC Particles Toughened Si3N4-Based Ceramics

2020 ◽  
Vol 20 (3) ◽  
pp. 1709-1714
Author(s):  
Liang Tian ◽  
Qinglin Hou ◽  
Yingxia Wang ◽  
Yihui Hou ◽  
Li Li
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Injection Moulding ◽  
Sintering Temperature ◽  
Toughening Mechanism ◽  
Comprehensive Properties ◽  
Backscattered Electron ◽  
Grain Distribution ◽  
Electron Imaging

In this article, nano-NbC particles toughened Si3N4-based ceramics were prepared by injection moulding and their mechanical properties along with toughening mechanism were studied. An increase of nano-NbC content, gradually homogenizes microstructure of the Si3N4-based ceramics along with increase in its density. However, the fracture toughness and flexural strength first increases and then decreases. The Si3N4-based ceramics demonstrate good comprehensive properties at the 15 wt% nano-NbC content and sintering temperature of 1550 °C (where the density is 85.3%, the flexural strength is 845 MPa, and the fracture toughness is 9.3 MPa·m1/2), Backscattered electron imaging shows that nano-NbC particles can be well dispersed in the Si3N4 ceramic matrix by injection moulding and ceramics are toughened by crack deflection and microcracking effects. It was also found that increasing sintering temperature makes the β-Si3N4 grain distribution more uniform by reducing the porosity.

Mechanical Properties of Al2O3-TiN Nanocomposite Ceramic Tool Materials

2012 ◽  
Vol 499 ◽  
pp. 108-113
Author(s):  
Yu Huan Fei ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
Holding Time ◽  
Bending Test ◽  
Ceramic Tool ◽  
Tool Materials ◽  
Nano Scale

Al2O3-TiN nanocomposite ceramic tool materials were fabricated by hot-pressing technique and the mechanical properties were measured. Mechanical properties such as room temperature flexural strength, Vickers hardness and fracture toughness were measured through three-point bending test and Vickers indentation. The effects of the content of nano-scale TiN, sintering temperature and holding time on the mechanical properties were investigated. The results shows that the addition of nano-scale TiN can improve the mechanical properties of alumina ceramics. Both the flexural strength and the fracture toughness first increased then decreased with an increment in the content of nano-scale TiN. Both the Vickers hardness and the fracture toughness increased with an increment in the sintering temperature. The flexural strength increased with an increment in the holding time, while the fracture toughness decreased with an increment in the holding time. The composites with only nano-scale TiN have the highest Vickers hardness for the holding time of 30min, while the hardness of the composites with nano-scale TiN and micro-scale TiN decreased with an increment in the holding time.

Sintering Effects on Mechanical Properties of Co-Ha Composite Prepared by Modified Electroless Deposition

2013 ◽  
Vol 594-595 ◽  
pp. 255-259
Author(s):  
Kasmuin Mohd Zaheruddin ◽  
Sri Asliza Md Amin ◽  
Azmi B. Rahmat ◽  
Shamsul Baharin Jamaludin ◽  
R.A. Khairel
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Flexural Strength ◽  
Bulk Density ◽  
Electroless Deposition ◽  
Sintering Temperature ◽  
Electroless Process ◽  
Percentage Porosity

Co-HA composite produced using electroless deposition without conventional sensitization and activation treatment was studied with varying sintering temperature (1100°C, 1200°C and 1250°C). The particles size, bulk density, porosity, hardness measurements and the flexural strength are performed in order to find the optimum sintering temperature. After the electroless process for 1 H, the particle size of HA increase to 3.9% and finally the value bulk density percentage of 93.08%, percentage porosity of 6.89%, hardness value of 291.8HV and flexural strength value of 42.4MPa have been achieved after pressing and sintering Co-HA composite at 1250°C. Observations were supporting the idea that Co-HA produced by modified electroless method was improving the mechanical properties with increasing the sintering temperature.

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