Measurement of the High Temperature Elastic Modulus of Alumina Ceramics by Different Testing Methods

2018 ◽  
Vol 768 ◽  
pp. 24-30
Author(s):  
Guang Lin Nie ◽  
Yi Wang Bao ◽  
De Tian Wan ◽  
Yuan Tian
Keyword(s):  
Elastic Modulus ◽  
High Temperature ◽  
Dynamic Method ◽  
Vibration Signal ◽  
Bending Test ◽  
Relative Method ◽  
Alumina Ceramics ◽  
Static Tests ◽  
Four Point Bending ◽  
Impulse Excitation

Alumina ceramics are widely used in the demanding high temperature applications in which the high temperature elastic moduli (EHT) is a key property for their reliability and safety. In this paper, the elastic modulus of alumina was determined by dynamic method (impulse excitation technique) and static tests (three-point bending test and four-point bending test). For the static tests, the relative method was applied to determine the accurate deflection measurement in the heating furnace. The measured results revealed that the modulus of alumina slowly decreased from RT to 1000 °C and rapidly decreased with the increasing temperatures from 1000 °C to 1300°C. The EHT evaluated by dynamic method were higher than that tested by static tests with the reason of that impulse excitation technique only applied small forces onto a sample such that defects activity is negligible. Also the resonant frequencies couldn’t be measured easily at high temperature, because the vibration signal emitted by the sample was weak. The static approaches combined with relative method were beyond the limit to high temperatures, and they can be also used to evaluate the ultra-high temperature modulus.

Determining Elastic Modulus of Ceramic Coatings at Elevated Temperature Using Impulse Excitation Technology

2016 ◽  
Vol 680 ◽  
pp. 13-16 ◽  
Author(s):  
Chen Guang Wei ◽  
Yi Wang Bao ◽  
Xue Qiang Cao ◽  
Zhao Liu ◽  
Yuan Tian
Keyword(s):  
Elastic Modulus ◽  
Elevated Temperature ◽  
Single Layer ◽  
Ceramic Coatings ◽  
Coated Sample ◽  
Multilayer Coatings ◽  
Relative Method ◽  
Impulse Excitation ◽  
Novel Method ◽  
Layer Coating

Although elastic modulus of ceramic coatings at elevated temperature is difficult to measure, it was evaluated in this work simply by impulse excitation tests based on the relative method that need only the measured moduli of coated sample and substrate. This novel method was demonstrated to be valid not only for the single layer coating but also for multilayer coatings.

High Temperature Mechanical Properties of a Crystallized BaO-B2O3-Al2O3-SiO2 Glass Ceramic for SOFC

2009 ◽  
Author(s):  
Hsiu-Tao Chang ◽  
Chih-Kuang Lin ◽  
Chien-Kuo Liu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Stress Relaxation ◽  
Flexural Strength ◽  
Glass Ceramic ◽  
Testing Temperature ◽  
Bending Test ◽  
High Temperature Mechanical Properties ◽  
Four Point Bending ◽  
The Given

The high temperature mechanical properties in a glass-ceramic sealant of BaO-B2O3-Al2O3-SiO2 system was studied by four-point bending test at room temperature, 550°C, 600°C, 650°C, and 700°C, to investigate the variation of Young’s modulus, flexural strength, and stress relaxation. Weibull statistic analysis was applied to describe the fracture strength of the given glass ceramic. The crystalline phase was produced by controlled heat treatment and analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the flexural strength was enhanced at high temperatures when the testing temperature was below the glass transition temperature (Tg). This was presumably due to a crack healing effect taking place at high temperature. Significant stress relaxation for the given glass ceramic was observed to generate extremely large deformation without breaking the specimens when the testing temperature was set at 700°C.

scholarly journals Evaluating high temperature elastic modulus of ceramic coatings by relative method

2017 ◽  
Vol 6 (4) ◽  
pp. 288-303 ◽  
Author(s):  
Guanglin Nie ◽  
Yiwang Bao ◽  
Detian Wan ◽  
Yuan Tian
Keyword(s):  
Elastic Modulus ◽  
High Temperature ◽  
Ceramic Coatings ◽  
Relative Method

Analysis of iron aluminide coated beams under creep conditions in high-temperature four-point bending tests

2018 ◽  
Vol 53 (4) ◽  
pp. 255-265 ◽  
Author(s):  
Joachim Nordmann ◽  
Philipp Thiem ◽  
Nuria Cinca ◽  
Konstantin Naumenko ◽  
Manja Krüger
Keyword(s):  
High Temperature ◽  
Creep Behaviour ◽  
Substrate Material ◽  
Iron Aluminide ◽  
Bending Test ◽  
Bending Tests ◽  
Four Point Bending ◽  
Wear And Corrosion ◽  
Four Point Bending Test ◽  
Wear And Corrosion Resistance

Recent research is focused on the possibility to coat a metallic alloy with intermetallics or ceramics to improve wear and corrosion resistance, as well as creep behaviour at high temperatures, next to other properties of the alloy. Nowadays, this gains importance due to stricter environment guidelines. Here, we present a model to describe a non-symmetric compound in a high-temperature four-point bending test, performed at [Formula: see text]. The substrate material is an aluminium alloy AlSi10MgT6, and the coating material is the iron aluminide Fe24Al0.6Nb. Up next, a layer-wise theory is introduced to calculate the forces between substrate and coating. Furthermore, required material parameters are identified, and a new procedure to determine Young’s modulus of a coating is presented. Finally, simulation results are compared to experimental data, illustrating that the presented model is able to describe the material behaviour accurately.

scholarly journals Investigation of the Elastic Modulus of Polymer Sleepers Under a Quasistatic and Cyclic Loading

2019 ◽  
Vol 15 (2) ◽  
pp. 125-133
Author(s):  
Vít Lojda ◽  
Aran van Belkom ◽  
Hana Krejčiříková
Keyword(s):  
Elastic Modulus ◽  
Cyclic Loading ◽  
Prestressed Concrete ◽  
Load Level ◽  
Bending Test ◽  
Elastic Behaviour ◽  
Loading Frequency ◽  
Wheel Load ◽  
Four Point Bending ◽  
Four Point Bending Test

AbstractIn ballasted track, the wheel load is transmitted to the subgrade via sleepers commonly made of impregnated wood, prestressed concrete, steel or recently developed polymer sleepers. Mentioned material types of sleepers are characterized by different elastic moduli being a key parameter in any numerical model. Hence, this paper aims to determine the elastic modulus of sleepers subjected to a laboratory four-point bending test. Traffic resembling load level of 60 kN adopted from a typical axle load distributed by the rails to the sleeper was applied in a quasistatic and cyclic loading. The samples included sleepers made of polymers complemented with wood and pre-stressed concrete. The results of this paper are based on the elastic modulus investigation. Main conclusions are focused on the sleeper’s elastic modulus under changing loading frequencies. Wood and prestressed concrete sleepers indicated mainly elastic behaviour resulting in a constant elastic modulus. However, polymer sleepers showed a loading frequency dependent elastic modulus as a result of their viscous elastic behaviour. Moreover, the conclusions of this paper involve E-modulus measurements of impregnated beech sleepers in order to describe their piece by piece elasticity variation due to their natural origin.

scholarly journals Estimation of the Modulus Fir Wood Reinforced With PBO Fiber Mesh

2018 ◽  
Vol 64 (4) ◽  
pp. 105-121
Author(s):  
P. Sokołowski ◽  
P. G. Kossakowski
Keyword(s):  
Elastic Modulus ◽  
Bearing Capacity ◽  
Modulus Of Elasticity ◽  
Bending Test ◽  
Load Bearing Capacity ◽  
Four Point Bending ◽  
University Of Technology ◽  
Pbo Fiber ◽  
Four Point Bending Test ◽  
Fiber Mesh

AbstractThis paper presents the results of preliminary tests for estimating the modulus of elasticity of wooden beams from firs reinforced with PBO fiber mesh. The tests were carried out in the Materials Strength Laboratory at the Kielce University of Technology in Kielce, Poland with PN-EN 408: 2004. The wooden elements were subjected to a four-point bending test with the aim of estimating the elastic modulus when bending, assuming the loading velocities of the loading forces of 5 mm / min. The obtained results show a significant increase in the load-bearing capacity of beams reinforced with PBO mesh.

Inverse characterisation of gradient distribution of the modulus of bamboo using a four-point bending test

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xianzhi Gao ◽  
Guangyan Liu ◽  
Lu Wang ◽  
Yanan Yi ◽  
Guang Lin ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Model Updating ◽  
Volume Fraction ◽  
Image Correlation ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Gradient Distribution ◽  
Outer Skin ◽  
Four Point Bending ◽  
Four Point Bending Test

AbstractAs a natural graded material, bamboo has gradually increasing elastic modulus along the radial direction from the inner to the outer skin. Accurate measurement of the modulus distribution plays an important role in bamboo-based structural design. However, it is difficult to characterise this modulus distribution by using conventional testing approaches on bamboo slices. A more effective method was developed in this study for the inverse identification of gradually varying material properties. The method is based on the digital image correlation and finite element model updating techniques. The radial distribution of the elastic modulus of bamboo was obtained through only one four-point bending test. The inversely identified modulus distribution was verified through uniaxial tensile tests on sliced bamboo strips and microscopic observation of the volume fraction distribution of its vascular bundle. The results showed that the elastic modulus of the bamboo material decreased from the outer skin (20 GPa) to the inner skin (2 GPa), which is in good consistence with the tensile test results on sliced specimens.

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