A Study on Metal-Ceramic Thermal Expansion Compatibility

2014 ◽  
Vol 216 ◽  
pp. 85-90
Author(s):  
Marian Miculescu ◽  
Mihai Branzei ◽  
Florin Miculescu ◽  
Daniela Meghea ◽  
Marin Bane
Keyword(s):  
Thermal Expansion ◽  
Bonding Strength ◽  
Linear Thermal Expansion ◽  
Metal Bonding ◽  
Thermal Expansion Coefficients ◽  
Metal Ceramic ◽  
Thermal Compatibility ◽  
Expansion Coefficients ◽  
The Difference ◽  
Dental Applications

Push rod method for determining linear thermal expansion using vertical differential dilatometer was used in the study of the thermal compatibility of metal-ceramic systems for dental applications. The purpose of this study consisted in evaluating the effectiveness of dental coating by determining the ceramic metal bonding strength of metal-ceramic couples (Ni-Cr and Co-Cr alloy coated with dental ceramic) and correlation with the difference of linear thermal expansion coefficients of metals and ceramics.

scholarly journals Thermal analysis of metal-ceramic bonding using finite element method

2014 ◽  
Vol 3 (2) ◽  
pp. 216 ◽  
Author(s):  
S. Gopinath ◽  
R Sabarish ◽  
R. Sasidharan
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Bonding Strength ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Processing Temperature ◽  
Element Analysis ◽  
Metal Ceramic ◽  
The Difference

This paper reports a finite element study of effect of bonding strength between metal and ceramic. The bonding strength is evaluated with different processing temperature and holding time. The difference between the coefficients of linear thermal expansion (CTEs) of the metal and ceramic induces thermal stress at the interface. The mismatch thermal stress at the interface region plays an important role in improving bonding strength. Hence, it is essential to evaluate the interface bonding in metal-ceramics joints. The Al/SiC bonding was modeled and analyzed using finite element analysis in ANSYS (v.10). Keywords: Bonding Strength, Coefficient of Thermal Expansion, Thermal Stress, Interface, Al/Sic, FEA.

scholarly journals Temperature-dependent structural behaviour of samarium cobalt oxide

2017 ◽  
Vol 32 (S2) ◽  
pp. S38-S42
Author(s):  
Matthew R. Rowles ◽  
Cheng-Cheng Wang ◽  
Kongfa Chen ◽  
Na Li ◽  
Shuai He ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Cobalt Oxide ◽  
Sol Gel ◽  
Linear Thermal Expansion ◽  
Rietveld Analysis ◽  
Structural Behaviour ◽  
Temperature Dependent ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Sol Gel Synthesis

The crystal structure and thermal expansion of the perovskite samarium cobalt oxide (SmCoO3) have been determined over the temperature range 295–1245 K by Rietveld analysis of X-ray powder diffraction data. Polycrystalline samples were prepared by a sol–gel synthesis route followed by high-temperature calcination in air. SmCoO3 is orthorhombic (Pnma) at all temperatures and is isostructural with GdFeO3. The structure was refined as a distortion mode of a parent $ Pm{\bar 3}m $ structure. The thermal expansion was found to be non-linear and anisotropic, with maximum average linear thermal expansion coefficients of 34.0(3) × 10−6, 24.05(17) × 10−6, and 24.10(18) × 10−6 K−1 along the a-, b-, and c-axes, respectively, between 814 and 875 K.

Measurement of thermal expansion coefficient of substrate GGG and its epitaxial layer YIG

1999 ◽  
Vol 14 (1) ◽  
pp. 2-4 ◽  
Author(s):  
Rui-sheng Liang ◽  
Feng-chao Liu
Keyword(s):  
Thin Film ◽  
Thermal Expansion ◽  
Single Crystal ◽  
Thermal Expansion Coefficient ◽  
Epitaxial Layer ◽  
Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
New Method ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

A new method is used in measuring the linear thermal expansion coefficients in composite consisting of a substrate Gd3Ga2Ga3O12 (GGG) and its epitaxial layer Y3Fe2Fe3O12 (YIG) within the temperature range 13.88 °C–32.50 °C. The results show that the thermal expansion coefficient of GGG in composite is larger than that of the GGG in single crystal; the thermal expansion coefficient of thick film YIG is also larger than that of thin film. The results also show that the thermal expansion coefficient of a composite consisting of film and its substrate can be measured by using a new method.

Preparation and Characterization of Thermally Compatible Leucite-Reinforced Dental Ceramics

2011 ◽  
Vol 308-310 ◽  
pp. 311-314
Author(s):  
Jin Wen ◽  
Shu Zhen Sun
Keyword(s):  
Thermal Expansion ◽  
Dental Ceramics ◽  
Dental Porcelain ◽  
Thermal Expansion Coefficients ◽  
High Thermal Expansion ◽  
Coprecipitation Technique ◽  
Thermal Compatibility ◽  
The Common ◽  
Expansion Coefficients

The high average thermal expansion required for thermal compatibility of dental porcelain with their substrate alloy is supplied by the mineral leucite (KAlSi2O6). In the research, the high thermal expansion coefficients phase leucite was prepared by coprecipitation technique. Three materials with formulae of K2O∶Al2O3∶SiO2= 1∶1∶x ( x=1.4, 2.0, 4.0 ) were investigated for differences in phase, thermal expansion. Unstoichiometric composition where K2O and Al2O3were added properly is advantage to leucite obtained. Coprecipitation processing produced fine leucite powder that would sinter at 1300°C, this temperature is about 200°C lower than of melting method. The average thermal expansion coefficients of leucite is 22.7×10-6/°Cfrom room temperature to 620°C,which is higher than the common porcelain. Changing in the leucite content of dental porcelain would results from thermal expansion coefficients of porcelain variation, which could be responsible for changes in porcelain-metal thermal compatibility.

Negative Thermal Expansion of Yb2Mo3O12 and Lu2Mo3O12

2008 ◽  
Vol 368-372 ◽  
pp. 1662-1664 ◽  
Author(s):  
X.L. Xiao ◽  
M.M. Wu ◽  
J. Peng ◽  
Y.Z. Cheng ◽  
Zhong Bo Hu
Keyword(s):  
Thermal Expansion ◽  
Solid State ◽  
Solid State Reaction ◽  
Linear Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Orthorhombic Structure ◽  
Conventional Solid State Reaction ◽  
Temperature Range ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

Compounds Yb2Mo3O12 and Lu2Mo3O12 were prepared by conventional solid-state reaction. Their crystal structures and thermal expansion properties were investigated. It was found that Yb2Mo3O12 and Lu2Mo3O12 adopt orthorhombic structure and show negative thermal expansion (NTE) in the temperature range of 200-800 °C. Their a-axis and c-axis exhibit stronger contraction in the temperature range of 200-800 °C, while b-axis slightly expands in the temperature range of 200-300 °C and then contracts in the temperature range of 300-800 °C. The linear thermal expansion coefficients al of Yb2Mo3O12 and Lu2Mo3O12 are −5.17 × 10−6 °C−1 and −5.67 × 10−6 °C−1, respectively.

Athermal Motion of Grain Boundaries, Twins and Triple Junctions in Zn

2004 ◽  
Vol 467-470 ◽  
pp. 801-806 ◽  
Author(s):  
Vera G. Sursaeva
Keyword(s):  
Thermal Expansion ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Triple Junction ◽  
Triple Junctions ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
The Difference ◽  
The Individual ◽  
Individual Grains

When a bicrystal or polycrystal are subjected to a change in temperature, the individual responses of the two adjoining crystals may differ in a manner, which tends to produce a dilatational mismatch along grain boundaries. If compatibility is to be retained along the interface, an additional set of stresses must then be generated in order to conserve this compatibility. ‘Compatibility stresses’ will also be generated whenever a polycrystal is heated or cooled and the thermal expansion coefficients of the individual grains are different due to thermal expansion anisotropy. In such cases adjacent grains will attempt to change dimensions and develop mismatches by amounts controlled by the parameter Δa*ΔΤ, where Δa is the difference between the thermal expansion coefficients in the appropriate directions, and ΔΤ is the temperature change. These ‘compatibility stresses’ may be relieves if grain boundary motion, triple junction migration and grain growth are possible. These ‘compatibility stresses’ may play important role in the kinetic behavior of the microstructure ranging from influencing the behavior of lattice dislocations near the grain boundaries to promoting grain boundary and triple junction dragging or moving. The motion of the ‘special’ grain boundaries, triple junctions with ‘special’ grain boundaries and twins under the influence of internal mechanical stresses is the main subject of this paper.

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