Numerical Simulation on Thermal Shock Resistance of TiB2-Cu Interpenetrating Phase Composites

2005 ◽  
Vol 475-479 ◽  
pp. 1551-1554
Author(s):  
Chang Qing Hong ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Xiao Dong He
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Stress Fields ◽  
Severe Condition ◽  
Copper Powders ◽  
Arc Heater ◽  
Shock Resistance ◽  
Thermal Shock Behavior ◽  
Experimental And Numerical Modeling ◽  
Interpenetrating Phase Composites

TiB2-Cu Interpenetrating phase composites (IPCs) were prepared by combustion synthesis of elemental titanium, boron and copper powders. The synthesized product consisted of two spatial continuous phases: TiB2 and copper. Using the experimental data, thermo-physical and mechanical parameters of the materials established the temperature and stress fields made of FEM. Thermal shock behavior of TiB2-Cu IPCs was also investigated using a plasma torch arc heater and the results showed no cracks were found on the thermal shock surface of the TiB2-Cu IPCs. The experimental and numerical modeling results can be used to explain the actual thermal shock resistance and reveal its complex behavior under the severe condition.

Thermal shock resistance of TiB2–Cu interpenetrating phase composites

2005 ◽  
Vol 65 (11-12) ◽  
pp. 1711-1718 ◽  
Author(s):  
Jiecai Han ◽  
Changqing Hong ◽  
Xinghong Zhang ◽  
Baolin Wang
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Shock Resistance ◽  
Interpenetrating Phase Composites

Thermal Shock Behavior and Bonding Strength of MoSi2-BaO-Al2O3-SiO2 Gradient Porous Coating with Polymethyl Methacrylate Addition for Porous Fibrous Insulations

2018 ◽  
Vol 281 ◽  
pp. 493-498
Author(s):  
Ya Yu Su ◽  
Xiao Lei Li ◽  
Hui Jie Tang ◽  
Zhi Hao Zhao ◽  
Jian He
Keyword(s):  
Porous Structure ◽  
Thermal Shock ◽  
Bonding Strength ◽  
Thermal Shock Resistance ◽  
Porous Coating ◽  
Bonding Layer ◽  
Interface Bonding ◽  
Shock Resistance ◽  
Thermal Shock Behavior ◽  
Interface Bonding Strength

In order to improve the thermal shock behavior of high temperature resistant coating on porous fibrous referactory insulations, the MoSi2-BaO-Al2O3-SiO2(MoSi2-BAS) gradient porous coatings were designed by preparing a dense surface layer and a porous bonding layer with the method of brushing and subsequent sintering at 1773 K. The porous bonding layer was obtained by adding polymethyl methacrylate (PMMA) as pore former. As the content of PMMA increases, the MoSi2-BAS coatings changed from a dense structure into a gradient porous structure. The interface bonding strength and thermal shock resistance of the MoSi2-BAS coatings were investigated. The result shows that the as-prepared coating with gradient porous structure exhibited excellent thermal shock resistance, which remained gradient structure without cracking after thermal cycling 100 times between 1773 K and room temperature. And the interface bonding strength of the gradient porous coating reached 1.5±0.08 Mpa, which was much better than that of the dense coating.

Evaluation of Thermal Shock Resistance of Alumina Ceramics

2011 ◽  
Vol 492 ◽  
pp. 333-336
Author(s):  
Kai Li ◽  
Lu Cun Guo
Keyword(s):  
Flexural Strength ◽  
Thermal Shock ◽  
Temperature Difference ◽  
Thermal Shock Resistance ◽  
Alumina Ceramics ◽  
Sharp Drop ◽  
Quenching Temperature ◽  
Before And After ◽  
Shock Resistance ◽  
Thermal Shock Behavior

The thermal shock behavior of alumina ceramics tested by two different approaches, water and air quenching, using an automatic experimental set was investigated. The changes of the flexural strength before and after the thermal shock was measured and used as an indicator of thermal shock resistance. The study reveals that air quenching test has limited impact on the changes of flexural strength, whereas the water quenching yields considerable decreases of the strength. The alumina ceramics was quenched in water at various temperature differences for five cycles. It is shown that the retained strength of the quenched specimens decreases abruptly at the temperature difference of 300°C, which indicates a great severity of thermal shock in this point. The thermal shock behavior of the specimens is evaluated by quenching in water as three different temperature differences, ΔT, setting at 300°C, 600°C and 800°C, respectively. The results show, for three different ΔT quenches, the strength reductions caused by the quenching exhibit similar trends: After a sharp drop, the residual strength remains almost unchanged at a certain level for each given quenching temperature difference, and the turning points all fall in the very first five to ten thermal cycles range. And the rank of the damage severity of alumina ceramics among the three different temperature differences is: ΔT800°C > ΔT600°C > ΔT300°C

The Thermal Shock Resistance of Mg-PSZ/LaPO4 Ceramics

2013 ◽  
Vol 785-786 ◽  
pp. 187-190
Author(s):  
Zhong Qiu Li ◽  
Li Jie Ci ◽  
Tie Cheng Feng ◽  
Shao Yan Zhang
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Strength Degradation ◽  
Water Quenching ◽  
Bending Test ◽  
Three Point Bending ◽  
Shock Resistance ◽  
Thermal Shock Behavior

The mechanical properties and thermal shock behavior of Mg-PSZ/LaPO4 ceramics was investigated. The thermal shock resistance of the materials was evaluated by water quenching and a subsequent three-point bending test to determine the flexural strength degradation. Mg-PSZ/15LaPO4 composite showed a higher thermal shock resistance and behaved as a typical refractory. The calculation of thermal shock resistance parameters for the composites and the monolith had indicated possible explanations for the differences in thermal shock behavior.

Thermal Shock Behavior of Calcia Stabilized Zirconia Ceramics with Porosity Gradient Structure

2009 ◽  
Vol 631-632 ◽  
pp. 435-440
Author(s):  
Qiang Shen ◽  
Chang Lian Chen ◽  
Fei Chen ◽  
Qi Wen Liu ◽  
Lian Meng Zhang
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Gradient Structure ◽  
Monoclinic Zirconia ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
The Matrix ◽  
Shock Resistance ◽  
Thermal Shock Behavior

Porous calcia stabilized zirconia ceramics (CSZC) with closed pores were presurelessly sintered by adding different contents of zirconia hollow balls. CSZC FGM with porosity gradient structure was then fabricated by laminating five layers with designed contents of zirconia hollow balls. The porosity, microstructure, and bending strength of the obtained CSZC samples were characterized. The results show that the hollow balls distribute uniformly and are well bonded with the matrix, and the porous structure is mainly composed of closed pores. The porosity of the CSZC increases linearly from 5.7 % to 31.6 % when the content of zirconia hollow balls increases from 0 % to 30 %, and the bending strength decreases rapidly from 297 MPa to 30 MPa. The thermal shock behavior of the CSZC and FGM was evaluated using air-quenching technique. It is shown that the residual bending strength of the quenched samples increases after several quenching cycles, and the samples are damaged by thermal shock after eight thermal cycles because of the production of monoclinic zirconia. FGM samples with porosity gradient structure can endure above twelve thermal shock cycles and exhibits better thermal shock resistance.

Investigation of Mechanical Property and Thermal Shock Behavior of Machinable B4C/BN Ceramics Composites

2008 ◽  
Vol 569 ◽  
pp. 53-56
Author(s):  
Tao Jiang ◽  
Hai Yun Jin ◽  
Zhi Hao Jin ◽  
Jian Feng Yang ◽  
Guan Jun Qiao
Keyword(s):  
Mechanical Property ◽  
Fracture Toughness ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Sintering Process ◽  
Shock Temperature ◽  
Shock Resistance ◽  
Thermal Shock Behavior ◽  
Hot Pressing Sintering ◽  
Better Than

The machinable B4C/BN ceramics composites were fabricated by hot-pressing sintering process at 1850oC for 1h under the pressure of 30MPa. The mechanical property, thermal shock behavior and machinability of the B4C/BN ceramics composites were investigated in this article. The experimental results showed that the fracture strength and fracture toughness of the B4C/BN nanocomposites were significantly improved in comparison with the B4C/BN microcomposites. The Vickers hardness of the B4C/BN nanocomposites and B4C/BN microcomposites decreased gradually with the increasing content of h-BN, while the machinability of the B4C/BN nanocomposites and B4C/BN microcomposites were significantly improved. The B4C/BN ceramics composites with the h-BN content more than 20wt% exhibited excellent machinability. The thermal shock resistances of the B4C/BN ceramics composites were better than that of the B4C monolith, and the thermal shock resistance of the B4C/BN nanocomposites was much better than that of the B4C/BN microcomposites. The thermal shock temperature difference (-Tc) of B4C monolith was about 300oC, while the -Tc of the B4C/BN microcomposites was about 500oC, the -Tc of the B4C/BN nanocomposites was about 600oC.

Preparation and Characterization of Zirconia-Yttria/Zirconia-Magnesia Composites

2006 ◽  
Vol 530-531 ◽  
pp. 389-394 ◽  
Author(s):  
E. Caproni ◽  
R. Muccillo
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Electrical Response ◽  
X Ray Diffraction ◽  
Oxygen Pump ◽  
Impedance Spectroscopy Technique ◽  
Shock Resistance ◽  
Materials Used ◽  
Thermal Shock Behavior ◽  
Better Than

ZrO2: 3mol% Y2O3 powders were mixed in different proportions to ZrO2: 8 mol% MgO, pressed and sintered at 1500°C for producing composites with oxygen ion conductivity better than that of ZrO2: 8 mol% MgO and thermal shock resistance better than that of ZrO2: 3 mol% Y2O3. The electrical conductivity was evaluated by the impedance spectroscopy technique at 600°C as a function of the partial pressure of oxygen using zirconia-based oxygen pump and sensor. The thermal shock resistance was studied by room temperature- 1550°C dilatometry on sintered pellets. Moreover the composites were studied by X-ray diffraction and scanning electron microscopy. All composites are partially stabilized in the monoclinic-tetragonal phase and the apparent density is higher than 90% of the theoretical density. The thermal shock behavior of the composites is similar to that of ZrO2:8 mol% MgO materials used in disposable high temperature oxygen sensors. The electrical response of the composites at high temperatures is better than the electrical response of ZrO2:8 mol% MgO.

Thermal Shock Resistance and Ablation Behavior of TiB2-Cu-Ni Composite via Combustion Synthesis

2007 ◽  
Vol 336-338 ◽  
pp. 1513-1516
Author(s):  
Zhang Yong ◽  
Xing Hong Zhang ◽  
Qiang Xu
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Hot Isostatic Pressing ◽  
Critical Energy ◽  
Critical Energy Release Rate ◽  
Cu Alloy ◽  
High Temperature Synthesis ◽  
Arc Heater ◽  
Mechanical Erosion ◽  
Shock Resistance

TiB2-Cu-Ni cermet composite was fabricated by self-propagating high-temperature synthesis combined with Pseudo Hot Isostatic Pressing. The microstructure of the composite is fine and uniform. The thermal shock resistance and ablation behavior of the TiB2-Cu-Ni composite was investigated by heating it for twenty seconds using a plasma torch arc heater. Fatal breakup took place in the monolithic TiB2 ceramic once the plasma arc flow faced the surface of the ceramic. Only a small crack was found on the ablation surface of the TiB2-Cu-Ni composite. The thermal stress fracture resistance parameter, R, and the critical energy release rate GIC of TiB2-Cu-Ni composite are at the same order with that of the W/Cu alloy. It showed that the properties of thermal shock resistance and the ablation of the composite are good. The fraction of mass loss of the homogeneous composite was 2.32 %, which was similar to that of traditional W/Cu alloy. The volatilization of the metal binder and mechanical erosion was the main mechanisms of the ablation.

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