Analyses of Young's modulus and thermal expansion coefficient of sintered porous alumina compacts

This paper proposes a measuring apparatus and method for simultaneous determination of the thermal expansion coefficient and biaxial Young’s modulus of indium tin oxide (ITO) thin films. ITO thin films simultaneously coated on N-BK7 and S-TIM35 glass substrates were prepared by direct current (DC) magnetron sputtering deposition. The thermo-mechanical parameters of ITO thin films were investigated experimentally. Thermal stress in sputtered ITO films was evaluated by an improved Twyman–Green interferometer associated with wavelet transform at different temperatures. When the heating temperature increased from 30 °C to 100 °C, the tensile thermal stress of ITO thin films increased. The increase in substrate temperature led to the decrease of total residual stress deposited on two glass substrates. A linear relationship between the thermal stress and substrate heating temperature was found. The thermal expansion coefficient and biaxial Young’s modulus of the films were measured by the double substrate method. The results show that the out of plane thermal expansion coefficient and biaxial Young’s modulus of the ITO film were 5.81 × 10−6 °C−1 and 475 GPa.

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Size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient of thin films

Physical Chemistry Chemical Physics ◽

10.1039/c6cp03294j ◽

2016 ◽

Vol 18 (31) ◽

pp. 21508-21517 ◽

Cited By ~ 8

Author(s):

Xiao-Ye Zhou ◽

Bao-Ling Huang ◽

Tong-Yi Zhang

Keyword(s):

Thin Films ◽

Thermal Expansion ◽

Young’S Modulus ◽

Thermal Expansion Coefficient ◽

Expansion Coefficient ◽

Material Properties ◽

Essential Role ◽

Young's Modulus ◽

Temperature Dependent ◽

Size Dependent

Surfaces of nanomaterials play an essential role in size-dependent material properties.

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Development of Porous Material with High Young’s Modulus and Low Thermal Expansion Coefficient in SiC-Vitrified Bonding Material-LiAlSiO4 System

Materials Science Forum ◽

10.4028/www.scientific.net/msf.620-622.715 ◽

2009 ◽

Vol 620-622 ◽

pp. 715-718 ◽

Cited By ~ 4

Author(s):

Tatsuya Ono ◽

Koji Matsumaru ◽

Isaías Juárez-Ramírez ◽

Leticia M. Torres-Martínez ◽

Kozo Ishizaki

Keyword(s):

Thermal Expansion ◽

Porous Material ◽

Porous Materials ◽

Young’S Modulus ◽

Thermal Expansion Coefficient ◽

Expansion Coefficient ◽

Large Scale ◽

Young's Modulus ◽

Negative Thermal Expansion ◽

Low Thermal Expansion

Machines for manufacturing large scale flat displays are enlarging as the size of glasses increases. This work develops porous materials with a low thermal expansion coefficient and a high Young’s modulus. SiC and LiAlSiO4 were used for a positive and a negative thermal expansion materials, respectively. Compositions of powders for porous materials were determined to obtain a desirable Young’s modulus and thermal expansion coefficient by using SiC-VBM-LiAlSiO4 phase diagram at 20 % of porosity. The empirical values of Young’s modulus and a thermal expansion coefficient are close to the theoretical values by using the diagram. Fabricated porous material had high enough Young’s modulus of 87 GPa, and low enough thermal expansion coefficient of 2 x 10-6 K-1 at temperatures ranging from -17 °C to 190 °C with 22 % of porosity.

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Robustness of Residual Stresses in Castings and an Improved Process Window

Volume 5: 35th Design Automation Conference, Parts A and B ◽

10.1115/detc2009-86454 ◽

2009 ◽

Cited By ~ 1

Author(s):

Magnus Hofwing ◽

Niclas Stro¨mberg

Keyword(s):

Finite Element ◽

Monte Carlo ◽

Thermal Expansion ◽

Monte Carlo Simulations ◽

Young’S Modulus ◽

Thermal Expansion Coefficient ◽

Expansion Coefficient ◽

Young's Modulus ◽

Process Window ◽

Quadratic Response

In this work the robustness of residual stresses in finite element simulations with respect to deviations in mechanical parameters in castings is evaluated. Young’s modulus, the thermal expansion coefficient and the hardening are the studied parameters. A 2D finite element model of a stress lattice is used. The robustness is evaluated by comparing purely finite element based Monte Carlo simulations and Monte Carlo simulations based on linear and quadratic response surfaces. Young’s modulus, the thermal expansion coefficient and the hardening are assumed to be normal distributed with a standard deviation that is 10% of their nominal value at different temperatures. In this work an improved process window is also suggested to show the robustness graphically. By using this window it is concluded that least robustness is obtained for high hardening values in combination to deviations in Young’s modulus and the thermal expansion coefficient. It is also concluded that quadratic response surface based Monte Carlo simulations substitute finite element based Monte Carlo simulations satisfactory. Furthermore, the standard deviation of the responses are evaluated analytically by using the Gauss formula, and are compared to results from Monte Carlo simulations. The analytical solutions are accurate as long as the Gauss formula is not utilized close to a stationary point.

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