Effects of Cr2O3 Content on Microstructure and Mechanical Properties of Al2O3 Matrix Composites

Al2O3-Cr2O3 refractories are completely substitution solid solutions and can effectively resist slag erosion when used as an industrial furnace lining. In order to provide suitable chromium corundum refractory with excellent slag resistance and mechanical properties for smelting reduction ironmaking, Al2O3-Cr2O3 samples with different mass percentages (0, 10, 20, 30, 40 wt.%) of Cr2O3 were prepared by a normal pressure sintering process to study its sintering properties, mechanical properties, thermal shock resistance, and microstructure. The results of densification behavior showed that the introduction of Cr2O3 deteriorates the compactness, the relative density and volume shrinkage rate of the composite material decrease with the increase of the Cr2O3 content, and the apparent porosity increases accordingly. In terms of mechanical properties, the hardness, compressive strength, and flexural strength of Al2O3-Cr2O3 material decrease gradually with the increase of Cr2O3. After 10 and 20 thermal shock cycles, the flexural strengths of the samples all decreased. With the increase of Cr2O3 in these samples, the loss rate of flexural strength gradually increased. Considering the slag resistance and mechanical properties of the composite material, the Al2O3-Cr2O3 composite refractory with Cr2O3 content of 20–30% can meet the requirements of smelting reduction iron making kiln lining.

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Compositional Optimum Design of the Ceramic Composite with Immune Genetic Algorithm

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.66-68.1562 ◽

2011 ◽

Vol 66-68 ◽

pp. 1562-1567 ◽

Cited By ~ 2

Author(s):

Hui Fa Zhang ◽

Chong Hai Xu ◽

Xing Hai Wang ◽

Jing Jie Zhang

Keyword(s):

Mechanical Properties ◽

Genetic Algorithm ◽

Fracture Toughness ◽

Composite Material ◽

Flexural Strength ◽

Optimum Design ◽

Ceramic Composite ◽

Immune Algorithm ◽

Immune Genetic Algorithm ◽

Optimum Material

In this paper, the immune genetic algorithm (IGA) is used to optimize the compositions of the Al2O3/SiC/Ti(C,N) ceramic composite material. Corresponding to the optimal mechanical properties such as fracture toughness, hardness and flexural strength, the optimum material compositions have been achieved. The convergent speed of IGA is faster than that of the single immune algorithm, and the number of iteration is also reduced obviously. As a result, the efficiency of optimization is increased.

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Processing and Properties of 2D Cf/Si-O-C Composites Using Silicone Resin

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1251 ◽

2007 ◽

Vol 336-338 ◽

pp. 1251-1253

Author(s):

Ke Jian ◽

Zhao Hui Chen ◽

Qing Song Ma ◽

Hai Feng Hu

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Carbon Fiber ◽

Flexural Strength ◽

Thermal Shock ◽

Silicon Oxycarbide ◽

Silicone Resin ◽

Carbon Fiber Cloth ◽

Thermal Shock Behavior ◽

First Time

SR-249, a kind of polysiloxane (PSO), was used as the precursor for the first time to fabricate carbon fiber cloth reinforced silicon oxycarbide (2D Cf/Si-O-C) composites. The cure and pyrolysis of the SR-249 as well as the mechanical properties, oxidation and thermal shock behavior of the composites were investigated in the paper. The flexural strength and fracture toughness of the composites reached 217.6 MPa and 12.5 MPa·m1/2, respectively. After soaked at 1300°C under the static air for 10 min, the composites retained 58.5% flexural strength and 64.5% fracture toughness. The thermal shock behavior of the composites was studied by water quenched method. The composites retained 49.3% flexural strength and 47.4% fracture toughness after 10 times of quenching from 1200 to 20°C.

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The Thermal Shock Resistance of Mg-PSZ/LaPO4 Ceramics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.785-786.187 ◽

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.

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Mechanical Properties and Ablation Behavior of Machinable ZrB2-SiC-BN Ceramics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.2011 ◽

2009 ◽

Vol 79-82 ◽

pp. 2011-2014 ◽

Cited By ~ 3

Author(s):

Hai Tang Wu ◽

Wei Gang Zhang

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Composite Material ◽

Flexural Strength ◽

Hot Pressing ◽

Effective Barrier ◽

Zirconium Silicate ◽

Ablation Resistance ◽

Ultrahigh Temperature ◽

Resistance Tests

ZrB2-SiC-BN ultrahigh-temperature ceramic (UHTC) was fabricated by hot-pressing at 1800°C under 23MPa pressure of argon. Compared to ZrB2-SiC, the flexural strength of ZrB2-SiC-BN composite material was enhanced by adding 30% BN, and the fracture toughness showed a slight decrease, while the hardness decreased sharply. The addition of 30% BN also noticeably improved the machinability of the composites. Furthermore, ablation resistance tests were carried out using an oxyacetylene torch under subsonic conditions. Results indicated that a coherent compact scale of zirconium silicate was formed, which acted as an effective barrier against the inward diffusion of oxygen.

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Effects of Thermal Shock on Mechanical Properties of Bamboo/PBS Green Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.123-125.1135 ◽

2010 ◽

Vol 123-125 ◽

pp. 1135-1138 ◽

Cited By ~ 1

Author(s):

Yeon Hee Lee ◽

Hitoshi Takagi ◽

Kazuya Ohkita ◽

Han Ki Yoon

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Thermal Shock ◽

Vickers Hardness ◽

Bamboo Fiber ◽

Bending Test ◽

Green Composites ◽

Nano Indentation ◽

Indentation Tests ◽

Bamboo Fibers

. This paper deals with the mechanical characterization of short bamboo fiber reinforced green composites (BFGC). The effects of thermal shock on the mechanical properties of BFGC were investigated. Their flexural strength was evaluated by 3-point bending test, and Vickers hardness and elastic modulus were evaluated by a nano-indentation method. The fracture surfaces and microstructure of BFGC were examined by SEM. The results of evaluated mechanical properties (3-point bending test) after thermal shock indicated that the strength of BFGC decreased below 40°C, however the strength became constant above 40°C. The Vickers hardness and modulus of elasticity evaluated from the nano-indentation tests also represented a similar trend to that of flexural strength. The fracture surface of thermal shocked BFGC after bending tests indicated the pull-outed bamboo fibers. This might be responsible for insufficient bonding between bamboo fiber and resin.

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Atomic structure of interface of intermetallic compound TiAl and nitride Ti2AIN using HREM and image processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087161 ◽

1991 ◽

Vol 49 ◽

pp. 570-571

Author(s):

E. Sukedai ◽

H. Mabuchi ◽

H. Hashimoto ◽

Y. Nakayama

Keyword(s):

Mechanical Properties ◽

Image Processing ◽

Composite Material ◽

Intermetallic Compound ◽

Side Surface ◽

High Resolution Electron Microscopy ◽

Hexagonal Structure ◽

Second Phase ◽

Resolution Electron ◽

Compound Tial

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.

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