Investigation into thermal expansion coefficient, thermal conductivity and thermal stability of Al-graphite composite prepared by powder metallurgy

2019 ◽  
Vol 773 ◽  
pp. 503-510 ◽  
Author(s):  
M. Esmati ◽  
H. Sharifi ◽  
M. Raeissi ◽  
A. Atrian ◽  
A. Rajaee
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Thermal Expansion ◽  
Powder Metallurgy ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Graphite Composite ◽  
Thermal Stability Of

Description of the PM Process by Using Ishikawa-Analysis

2013 ◽  
Vol 752 ◽  
pp. 48-56
Author(s):  
Andrea Simon ◽  
Károly Kovács ◽  
C. Hakan Gür ◽  
Tadeusz Pieczonka ◽  
Zoltán Gácsi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Powder Metallurgy ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
High Strength ◽  
Manufacturing Technology ◽  
Low Density ◽  
Composite Manufacturing ◽  
Low Thermal Expansion

Composites are special material which can provide individual properties such as high strength with low density or good thermal conductivity with low thermal expansion coefficient. Composites conform to the constantly evolving and more complex expectations. In order to make a product with good quality, it is important to choose suitable materials and technology. In this research powder metallurgy (PM), as one of the most common composite manufacturing technology, was examined -which factors and mechanisms influence mostly the properties of the product. Ishikawa method was used to reveal these correlations.

A Simulation Analysis Research on the Material Performance of Resin Concrete

2013 ◽  
Vol 721 ◽  
pp. 135-138
Author(s):  
Bo Wang ◽  
Bin Lin ◽  
Kun Zhao
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Numerical Analysis ◽  
Thermal Expansion Coefficient ◽  
Cross Section ◽  
Expansion Coefficient ◽  
Simulation Analysis ◽  
Analysis Method ◽  
Accumulation Model ◽  
Thermal Stability Of

A numerical analysis method of the thermal stability of the resin concrete is proposed in this paper. A 3D aggregate accumulation model based on the predecessors theory is established and a 2D cross section is directly captured from it. In order to simplify the analysis, a kind of conversion program is developed. The thermal expansion coefficient of established model is close to previous research results. It confirms the analysis method is correct. By the results, a reliable formula is found to calculate the thermal expansion coefficient and a method to reduce the thermal expansion coefficient of resin concrete is proposed.

Design, Preparation and Thermal Properties of (La0.4Sm0.5Yb0.1)2Zr2O7 Ceramic for Thermal Barrier Coatings

2012 ◽  
Vol 512-515 ◽  
pp. 469-473 ◽  
Author(s):  
L. Liu ◽  
Z. Ma ◽  
F.C. Wang ◽  
Q. Xu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Rare Earth ◽  
Thermal Expansion Coefficient ◽  
Thermal Barrier Coatings ◽  
Expansion Coefficient ◽  
Phonon Transport ◽  
Thermal Barrier ◽  
Barrier Coatings

According to the theory of phonon transport and thermal expansion, a new complex rare-earth zirconate ceramic (La0.4Sm0.5Yb0.1)2Zr2O7, with low thermal conductivity and high thermal expansion coefficient, has been designed by doping proper ions at A sites. The complex rare-earth zirconate (La0.4Sm0.5Yb0.1)2Zr2O7 powder for thermal barrier coatings (TBCs) was synthesized by coprecipitation-calcination method. The phase, microstructure and thermal properties of the new material were investigated. The results revealed that single phase (La0.4Sm0.5Yb0.1)2Zr2O7 with pyrochlore structure was synthesized. The thermal conductivity and the thermal expansion coefficient of the designed complex rare-earth zirconate ceramic is about 1.3W/m•K and 10.5×10-6/K, respectively. These results imply that (La0.4Sm0.5Yb0.1)2Zr2O7 can be explored as the candidate material for the ceramic layer in TBCs system.

Sintering Behavior of Plasma-Sprayed Sm2Zr2O7 Coating

2010 ◽  
Author(s):  
Jianhua Yu ◽  
Huayu Zhao ◽  
Shunyan Tao ◽  
Xiaming Zhou ◽  
Chuanxian Ding
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
High Temperature ◽  
Thermal Expansion Coefficient ◽  
Thermal Barrier Coating ◽  
Expansion Coefficient ◽  
Sintering Behavior ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Plasma Sprayed

Plasma-sprayed thermal barrier coating (TBC) systems are widely used in gas turbine blades to increase turbine entry temperature (TET) and better efficiency. Yttria stabilized zirconia (YSZ) has been the conventional thermal barrier coating material because of its low thermal conductivity, relative high thermal expansion coefficient and good corrosion resistance. However the YSZ coatings can hardly fulfill the harsh requirements in future for higher reliability and the lower thermal conductivity at higher temperatures. Among the interesting TBC candidates, materials with pyrochlore structure show promising thermo-physical properties for use at temperatures exceeding 1200 °C. Sm2Zr2O7 bulk material does not only have high temperature stability, sintering resistance but also lower thermal conductivity and higher thermal expansion coefficient. The sintering characteristics of ceramic thermal barrier coatings under high temperature conditions are complex phenomena. In this paper, samarium zirconate (Sm2Zr2O7, SZ) powder and coatings were prepared by solid state reaction and atmosphere plasma spraying process, respectively. The microstructure development of coatings derived from sintering after heat-treated at 1200–1500 °C for 50 h have been investigated. The microstructure was examined by scanning electron microscopy (SEM) and the grain growth was analyzed in this paper as well.

Effect of Thermal Process on the Microstructure and Property of Si/Al Composite with High Si Content

2012 ◽  
Vol 490-495 ◽  
pp. 3266-3271
Author(s):  
Yan Xia Li ◽  
Jun You Liu ◽  
Guo Quan Liu ◽  
Wen Shao Wang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Thermal Processing ◽  
Thermal Process ◽  
Primary Si ◽  
Al Composite ◽  
Semi Solid ◽  
Si Content

50vol. %Si/Al composite was prepared by the separation of liquid and solid in semi-solid. The microstructures of composite were obtained using OM, SEM and EMPA. The primary Si particles distribute uniformly on the Al matrix which surrounds the Si particles and makes-up a continuous network. The thermal expansion coefficient and thermal conductivity of composites experienced different thermal process were examined. It shows that the thermal process history has a significant effect on the microstructure and properties. The residual stress and size of Si particles varied during thermal processing which were responsible for the thermal expansion coefficient alternation. The thermal process of high temperature insostatic pressing reduces the porosity in composite and improves thermal conductivity obviously

Thermal Characteristics of Cu Matrix-SiC Filler Composite Using Nano-Sized Cu Powder

2021 ◽  
Vol 21 (9) ◽  
pp. 4964-4967
Author(s):  
Bok-Hyun Oh ◽  
Choong-Hwan Jung ◽  
Heon Kong ◽  
Sang-Jin Lee
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Liquid Phase Sintering ◽  
High Thermal Conductivity ◽  
Ceramic Filter ◽  
Ceramic Filler ◽  
Significant Difference

A Cu metal-ceramic filter composite with high thermal conductivity and a suitable thermal expansion coefficient was designed to be applied to high performance heat dissipation materials. The purpose of using the ceramic filler was to decrease the high coefficient of thermal expansion of Cu matrix utilizing the high thermal conductivity of Cu. In this study, a SiC ceramic filler powder was added to the Cu sol including Zn as a liquid phase sintering agent. The final complex was produced by applying a PVB polymer to prepare a homogeneous precursor followed by sintering in a reducing atmosphere. The pressureless sintered composite showed lower thermal conductivity than pure bulk Cu due to the some residual pores. In the case of the Cu–SiC composite in which 10 wt% of SiC filler was added, it showed a thermal conductivity of 100 W/m·°C and a thermal expansion coefficient of 13.3×10−6/°C. The thermal conductivity showed some difference from the theoretical calculated value due to the pores in the composite, but the thermal expansion coefficient did not show a significant difference.

A Promising LaSmZr2O7 Ceramic with Pyrochlore Structure for Thermal Barrier Coatings

2008 ◽  
Vol 368-372 ◽  
pp. 1328-1330
Author(s):  
Qiang Xu ◽  
Wei Pan ◽  
Chun Lei Wan ◽  
Long Hao Qi ◽  
He Zhuo Miao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Thermal Barrier Coatings ◽  
Expansion Coefficient ◽  
Pyrochlore Structure ◽  
Solid State Reaction Method ◽  
Rare Earth Ions ◽  
Thermal Barrier ◽  
Barrier Coatings

Based on La2Zr2O7 ceramic for thermal barrier coatings, LaSmZr2O7 ceramic doped with samarium ion was successfully prepared using solid state reaction method. The pellets were sintered at 1600°C for 10 hours in air. The phase structure, thermal conductivity and thermal expansion coefficient of LaSmZr2O7 ceramic and La2Zr2O7 ceramic were measured by XRD, laser-flash device, high-temperature dilatometry, respectively. The results show that the crystal structure of LaSmZr2O7 ceramic is not affected by the doped samarium ion in the zirconium lattice. The thermophysical results show that the thermal conductivity of the LaSmZr2O7 ceramic is lower than that of La2Zr2O7 ceramic, while the thermal expansion coefficient is higher than that of La2Zr2O7 ceramic. These results indicate that LaSmZr2O7 ceramic or Ln2Zr2O7 ceramics doped with other rare earth ions could be candidate materials for future thermal barrier coatings.

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