Bimaterial Micro-Structured Annulus With Zero Thermal Expansion Coefficient

2017 ◽  
Author(s):  
Yan Xie ◽  
Dengfeng Lu ◽  
Jingjun Yu
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
High Speed ◽  
Thermal Strain ◽  
Geometric Constraints ◽  
Geometrical Parameters ◽  
Thermal Behaviors ◽  
Lattice Cell ◽  
Triangular Cell

This paper mainly concentrates on the design and analysis of the annulus with zero thermal expansion coefficient (ZTE) aiming to solve the heat generation and deformation in high speed bearing. First, a fork-like lattice cell inspired by the basic triangular cell is put forward and further applied to construct an annulus. The stretch-dominated lattice cell utilizes the Poisson’s contraction effect to achieve the tailorable thermal expansion coefficient (CTE). The thermal behaviors differences between the continuous interfaces and lattice cells will lead to the internal stress. Thus, the CTE of the annulus consisting of the lattice cell can be tailored to zero even negative values through the offset between the thermal-strain and force-strain. Then a theoretical model is established with some appropriate assumptions to reveal the quantitative relations among the geometrical parameters, material properties and equivalent CTEs thoroughly. The prerequisites for realizing a zero CTE are further derived in terms of material limitations and geometric constraints. Finally, FEA method is implemented to verify and analyze the thermal behaviors of annulus. The proposed annulus design characterized by the CTE tunability, structure efficiency and continuous interfaces is hopefully to be applied in the high speed bearings, adapters between the shaft and collar and fastener screws.

Thermal Expansion Coefficient of Ni Base Alloy Composite Coating Containing Spheroidal Ceramic Grains

2010 ◽  
Vol 44-47 ◽  
pp. 2148-2151
Author(s):  
Xie Quan Liu ◽  
Xin Hua Ni ◽  
Shu Qin Zhang ◽  
Wan Heng He
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Composite Coating ◽  
Expansion Coefficient ◽  
Base Alloy ◽  
Thermal Strain ◽  
Phase Cell ◽  
Alloy Composite ◽  
Random Orientation ◽  
Two Phase

Ni base alloy composite coating containing spheroidal ceramic grains can be fabricated by a vacuum fusion sintering method. Composite coating was mainly composed of Ni base alloy and spheroidal ceramic grains with random orientation. The three-phase model is used to determine the thermal expansion coefficient of the composite coating. First, Eshebly-Mori-Tanaka method was used to determine thermal disturbance strain in two-phase cell aroused thermal inconsistency. Then, average thermal strain in the two-phase cell aroused by thermal inconsistency is gained by the means of volume equilibration. The two-phase cell is transverse isotropy and has two independent thermal expansion coefficients. Finely, based on mean strain of Ni base alloy ceramic composite coating containing spheroidal ceramic grains, the effective thermal expansion coefficient of the composite coating is obtained by considering random orientation of two-phase cells. Ni base alloy composite coating containing spheroidal ceramic grains is isotropy and has one independent thermal expansion coefficient.

scholarly journals THE INFLUENCE OF MORTAR MICROSTRUCTURE ON ITS THERMAL EXPANSION COEFFICIENT

2003 ◽  
Vol 9 (1) ◽  
pp. 45-51
Author(s):  
Darius Zabulionis ◽  
Gediminas Marčiukaitis
Keyword(s):  
Thermal Expansion ◽  
Bulk Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Composite Structure ◽  
Parametric Study ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Strain ◽  
Interfacial Transition Zone ◽  
Aggregate Fractions

Thermal strain is one of the factors causing additional stresses in a composite structure. It is necessary to calculate the coefficient of thermal expansion in evaluating thermal strains. According to the research, concrete is a material consisting of three phases: aggregate, interfacial transition zone (ITZ) and cement paste. The article presents the technique which enables the estimation of the thermal expansion coefficient of the mortar consisting of various aggregate fractions and covered with ITZ layer. A parametric study of various ITZ layer characteristics influencing the coefficient of thermal expansion has been carried out in the present paper. It has been determined that dry mortar or concrete could be treated as a material consisting of two components. While evaluating moist mortar or concrete it is necessary to take into account the depth of the ITZ the bulk modulus and the coefficient of thermal expansion.

scholarly journals Evaluation and analysis of the uncertainty measurement linear thermal expansion coefficient of ceramic brick

2021 ◽  
Vol 236 ◽  
pp. 02036
Author(s):  
Hui Gao ◽  
Zhengfa Yuan ◽  
Ming Gong ◽  
Wenjin Zhou ◽  
Bo Zhong ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
High Speed ◽  
Building Materials ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Ceramic Brick ◽  
Related Data ◽  
Uncertainty Measurement

With the continuous and high-speed growth of economy, people's requirements on product quality are increasing year by year, including ceramic brick products, which, as a typical building materials product, are widely used in all kinds of buildings of different sizes. Quality of brick of pottery and porcelain products mainly in the form of through the examination and evaluation. The uncertainty of measurement as an important part of the test results, is an important parameter characterization of the reliability of the measurement result. Therefore, this paper, the source of uncertainty in linear thermal expansion coefficient measurement of ceramic brick is analyzed, using the measurement results and related data, and concludes that for the linear thermal expansion coefficient average of 0.016%. when the report 2 sample average, the expanded uncertainty U (A) = 1.48%, contains the factor k = 2.

Control of Volume Fraction of Non-180° Domains by Thermal Strain in Epitaxial Rhombohedral Pb(Zr, Ti)O3 Thick Films

2013 ◽  
Vol 1507 ◽  
Author(s):  
Yoshitaka Ehara ◽  
Satoru Utsugi ◽  
Takahiro Oikawa ◽  
Tomoaki Yamada ◽  
Hiroshi Funakubo
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Growth Temperature ◽  
Volume Fraction ◽  
Thick Films ◽  
Thermal Strain ◽  
Cooling Process ◽  
Volume Fractions ◽  
Oriented Films

ABSTRACTEpitaxial rhombohedral Pb(Zr0.65Ti0.35)O3films with (100) and (110)/(10-1) and (111)/(11-1) orientations were grown on various kinds of singlecrystal substrates having different thermal expansion coefficient. Volume fractions of (110) and (111) orientations in respective (110)/(10-1) and (111)/(11-1)-oriented films were almost linearly increased with increasing thermal strain, εthermal, applied to the films that wasgenerated under the cooling process after the deposition from the growth temperature to the Curie temperature.Observed saturationpolarization (Psat)was changed linearly with the volume fractions of (110) and (111) orientations, in the same manner asthe volume fractions of (001) and (101) orientations in (001)/(100) and (101)/(110) oriented tetragonal Pb(Zr,Ti)O3 filmsreported previously. These results showed that the volume fraction of the non-180o domains Pb(Zr,Ti)O3films of both tetragonal and rhombohedral symmetriescan be manipulated by εthermal, which brings possibly to control the Psat value.

scholarly journals Out-of-Plane Thermal Expansion Coefficient and Biaxial Young’s Modulus of Sputtered ITO Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Chuen-Lin Tien ◽  
Tsai-Wei Lin
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Young’S Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Young's Modulus ◽  
Heating Temperature ◽  
Glass Substrates ◽  
Ito Thin Films

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.

scholarly journals Alternative of bone china and porcelain as ceramic hand molds for rubber latex glove films formation via dipping process

2020 ◽  
Vol 59 (1) ◽  
pp. 523-537
Author(s):  
Chaturaphat Tharasana ◽  
Aniruj Wongaunjai ◽  
Puwitoo Sornsanee ◽  
Vichasharn Jitprarop ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Mold Surface ◽  
Rubber Latex ◽  
Latex Glove ◽  
Bone China ◽  
Synthetic Rubber ◽  
Natural And Synthetic

AbstractIn general, the main compositions of porcelain and bone china composed of 54-65%wt silica (SiO2), 23-34% wt alumina (Al2O3) and 0.2-0.7%wt calcium oxide (CaO) suitable for preparation high quality ceramic products such as soft-hard porcelain products for teeth and bones, bioceramics, IC substrate and magneto-optoelectroceramics. The quality of ceramic hand mold is depended on raw material and its properties (pH, ionic strength, solid-liquid surface tension, particle size distribution, specific surface area, porosity, density, microstructure, weight ratio between solid and water, drying time, and firing temperatures). The suitable firing conditions for porcelain and bone china hand-mold preparation were firing at 1270°C for 10 h which resulted in superior working molds for making latex films from natural and synthetic rubber. The obtained fired porcelain hand molds at 1270°C for 10 h provided good chemical durability (10%NaOH, 5%HCl and 10%wtNaCl), low thermal expansion coefficient (5.8570 × 10−6 (°C−1)), good compressive (179.40 MPa) and good flexural strength (86 MPa). While thermal expansion coefficient, compressive and flexural strength of obtained fired bone china hand molds are equal to 6.9230 × 10−6 (°C−1), 128.40 and 73.70 MPa, respectively, good acid-base-salt resistance, a smooth mold surface, and easy hand mold fabrication. Both obtained porcelain and bone china hand molds are a low production cost, making them suitable for natural and synthetic rubber latex glove formation.

scholarly journals Modeling the effects of loading scenario and thermal expansion coefficient on potential failure of cryo-compressed hydrogen vessels

2020 ◽  
Vol 45 (46) ◽  
pp. 24883-24894 ◽  
Author(s):  
Ba Nghiep Nguyen ◽  
Daniel R. Merkel ◽  
Kenneth I. Johnson ◽  
David W. Gotthold ◽  
Kevin L. Simmons ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Potential Failure
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