Thermal Shock Damage and Mechanical Property of MoSi2 Materials by NDE Technique

2006 ◽  
Vol 321-323 ◽  
pp. 930-933 ◽  
Author(s):  
Sang Ll Lee ◽  
Young Ho Kim ◽  
Yun Seok Shin ◽  
Jin Kyu Lee ◽  
Joon Hyun Lee ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Ultrasonic Wave ◽  
Attenuation Coefficient ◽  
Detailed Examination ◽  
Linear Increase ◽  
Great Decrease ◽  
Surface Cracks ◽  
Nondestructive Technique

The mechanical property of sintered MoSi2 materials has been investigated, based on the detailed examination of their microstructures. The nondestructive technique by an ultrasonic wave was also used for evaluating the damage behaviors of MoSi2 materials suffered from the cyclic thermal shock. MoSi2 materials were sintered at the temperature of 1723 K. The flexural strength of MoSi2 materials gradually decreased with increasing the thermal shock cycle, accompanying the extensive creation of surface cracks. The increase of thermal shock cycles resulted in a great decrease of ultrasonic wave velocity and a linear increase of attenuation coefficient for MoSi2 materials.

CYCLIC THERMAL SHOCK PROPERTIES OF MOSI2 INTERMETALLIC MATERIALS

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2922-2927 ◽  
Author(s):  
SANG PILL LEE ◽  
JIN KYUNG LEE ◽  
CHAE HO LEEM
Keyword(s):  
Flexural Strength ◽  
Thermal Shock ◽  
Ultrasonic Wave ◽  
Attenuation Coefficient ◽  
Thermal Shock Test ◽  
Drastic Reduction ◽  
Nondestructive Technique ◽  
Shock Test ◽  
Damage Degree ◽  
Intermetallic Materials

This paper dealt with the thermal shock damages of MoSi 2 intermetallics by a nondestructive technique. The flexural strength of MoSi 2 intermetallics depending on the thermal shock cycles has been also investigated. The thermal shock test was repeatedly performed up to 80 cycles at the temperature difference of 423 K. The flexural strength of MoSi 2 intermetallics decreased with the increase of thermal shock cycle, due to the creation of crack and its propagation. MoSi 2 intermetallics represented the drastic reduction of ultrasonic wave velocity at the thermal shock of 40 cycles. The attenuation coefficient of MoSi 2 intermetallics increased with increasing the thermal shock cycle due to the activation of damage degree

Nondestructive Evaluation on Thermal Shock Damage of Ceramics

2006 ◽  
Vol 326-328 ◽  
pp. 697-700
Author(s):  
Jin Kyung Lee ◽  
Joon Hyun Lee ◽  
Sang Ll Lee
Keyword(s):  
Flexural Strength ◽  
Thermal Shock ◽  
Ultrasonic Wave ◽  
Crack Density ◽  
Alumina Ceramic ◽  
Water Tank ◽  
Ceramic Specimen ◽  
Micro Cracks ◽  
Wave Technique ◽  
Good Relation

The objective of this paper is to investigate the applicability of ultrasonic wave technique to monitor the progress of the thermal shock damage on alumina ceramic. For this purpose, alumina ceramic specimen was heated in the furnace and then was quenched into the water tank. The initiation, growth behaviors of surface micro-cracks as a function of the number of thermal shock cycle have been discussed by taking into account the change of ultrasonic wave velocity and attenuation. The change of both velocity and attenuation of ultrasonic wave showed good relation with the surface crack density changing due to the number of thermal shock cycle. Measuring the change of attenuation gives more effective information to evaluate thermal shock damage than that of velocity nondestructively. The flexural strength was also measured for the thermal shocked specimen. The flexural strength was decreased rapidly at the point of time of observation of microcracks on the surface of specimen, and the flexural strength decline by the crack growth caused thermal shock cycles was slight.

Effects of Nano-Al2O3 on the Mechanical Property and Microstructure of Nano-Micro Composite Self-Lubricating Ceramic Tool Material

2013 ◽  
Vol 770 ◽  
pp. 308-311 ◽  
Author(s):  
Ming Dong Yi ◽  
Chong Hai Xu ◽  
Zhao Qiang Chen ◽  
Guang Yong Wu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Tool Material ◽  
Ceramic Tool ◽  
Ceramic Tool Material ◽  
Composite Self ◽  
Microstructure And Mechanical Property ◽  
Grain Refinement Strengthening

A new nanomicro composite self-lubricating ceramic tool material was prepared with vacuum hot pressing technique. The effect of nanoAl2O3 powders on the microstructure and mechanical properties of nanomicro composite self-lubricating ceramic tool material was investigated. With the increase of nanoAl2O3 content, the hardness and fracture toughness first up then down. When the nanoAl2O3 content is 4 vol.%, the flexural strength, hardness and fracture toughness reaches 562 MPa, 8.46 MPa·m1/2 and 18.95 GPa, respectively. The microstructure and mechanical property of nanomicro composite self-lubricating ceramic tool material can be improved by the grain refinement strengthening of nanoAl2O3.

The Effect of Re-Dispersible Polymer Powders on Cement-Based Self-Leveling Mortar

2017 ◽  
Vol 730 ◽  
pp. 395-400 ◽  
Author(s):  
Shi Bing Sun ◽  
Jun Jie Li ◽  
Lun Zhao
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Abrasion Resistance ◽  
Micro Structure ◽  
Improve Performance ◽  
Microscopic Mechanism ◽  
Structure Surface ◽  
Construction Operation ◽  
Polymer Powders

The current paper experimentally investigated the effect of different kinds re-dispersible polymer powers (RPP) on cement-based self-leveling mortars. The construction operation of mortar and its mechanical property was tested in accordance with the standard JC/T 981-2005. Besides, the micro-structure surface of self-leveling mortar was characterized by means of SEM to reflect the microscopic mechanism of the performance. The results showed the dispersible polymer powders could significantly improve performance of fluidity, adhesion property and abrasion resistance on cement-based self-leveling mortar; Meanwhile, there is no bad impact on its compressive strength and flexural strength. This study has guiding significance for the construction and application of cement based self-leveling mortar.

Experimental Study on Ratio of Bending-Compressive Strength of the Crumb Rubber Concrete Modified by Latex

2014 ◽  
Vol 941-944 ◽  
pp. 761-764
Author(s):  
Wei Li ◽  
Zhen Huang ◽  
Xiao Chu Wang ◽  
Zi Sheng Zang
Keyword(s):  
Mechanical Property ◽  
Experimental Study ◽  
Compressive Strength ◽  
Surface Modification ◽  
Flexural Strength ◽  
Crumb Rubber ◽  
Interface Effect ◽  
Rubber Particles ◽  
Crumb Rubber Concrete ◽  
Rubber Concrete

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation about the ratio of bending-compressive strength of the crumb rubber concrete modified by latex,the concrete with various quantity of rubber,under the condition dosage of latex is 0.5% of cement quality.The result of experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio of bending-compressive strength could be enhanced at the same time.

Experimental Study on Proportion of Tensile Strength and Compressive Strength of the Crumb Rubber Concrete Modified by Latex

2014 ◽  
Vol 919-921 ◽  
pp. 1916-1919
Author(s):  
Wei Li ◽  
Zhen Huang ◽  
Xiao Chu Wang ◽  
Zi Sheng Zang
Keyword(s):  
Mechanical Property ◽  
Experimental Study ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Surface Modification ◽  
Flexural Strength ◽  
Crumb Rubber ◽  
Rubber Particles ◽  
Crumb Rubber Concrete ◽  
Rubber Concrete

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation of the ratio between tensile strength and compressive strength of the Crumb Rubber Concrete Modified by latex,the concrete with various quantity of rubber,under the condition Dosage of latex is 0.5% of cement quality.The result of Experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio between tensile strength and compressive strength could be enhanced at the same time.

Effect of Fumed Silica and Zinc Borate on the Thermogravimetric Analysis Curves of ABS/Magnesium Hydroxide Composite

2014 ◽  
Vol 599-601 ◽  
pp. 183-186
Author(s):  
Zhang Ting Li ◽  
Yue Qun Lu ◽  
Li Li Fan ◽  
Pei Bang Dai ◽  
Xia Su ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Thermal Stability ◽  
Flame Retardant ◽  
Fumed Silica ◽  
Acrylonitrile Butadiene Styrene ◽  
Zinc Borate ◽  
Processing Temperature ◽  
Great Decrease ◽  
Thermal Stability Of ◽  
Butadiene Styrene

For achieving sufficient flame retardancy, high magnesim hydroxide (MH) content is needed in MH flame retardant Acrylonitrile-butadiene-styrene copolymer (ABS) composites (ABS/MH), which will cause a great decrease in mechanical property and difficulty in preparing samples for measurement. We prepared ABS/MH filled high 60.0% flame retardant by compounding ABS and modified flame retardant MH, fumed silica (SiO2) and zinc borate (ZB) via TX-10 phosphate/polyacrylate latex and studied the effect of a small amount of SiO2 and ZB with MH in ABS for improving the thermal decomposition of ABS/MH. The thermal stability of the modified flame retardant could meet the processing temperature of ABS. The incorporation of ZB, SiO2 or SiO2/ZB could improve the thermal stability of ABS/MH.

Effect of AlF3 Content on Microstructure and Properties of Mullite/Al2O3 Composite Ceramics

2018 ◽  
Vol 922 ◽  
pp. 62-67
Author(s):  
Ke Zheng Sang ◽  
Fan Wang ◽  
De Jun Zeng ◽  
Hong Wei Li
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Diameter Ratio ◽  
Pressureless Sintering ◽  
Composite Ceramics ◽  
Microstructure And Properties ◽  
Shock Resistance ◽  
Mullite Whiskers

To reinforce the mullite/Al2O3 composite ceramics through formation of mullite whiskers, the composite ceramics were prepared by pressureless sintering using different AlF3 content. The microstructure, porosity, fracture toughness and thermal shock resistance of the composite ceramics were investigated. The results show that the addition of AlF3 can promote the mullite whisker formations, and the whiskers with the size of 3～10μm in diameter and a length-diameter ratio of 10～15 are obtained by sintering at 1600°C with the AlF3 content of 5wt%. Fracture toughness and thermal shock resistance of the composite ceramics are improved by the formation of mullite whisker. The fracture toughness of 4.79MPa•m1/2 can be obtained, and the 95.18% flexural strength remained after thermal shock.

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