scholarly journals Full density Cu-Invar composites with high thermal conductivity and low coefficient of thermal expansion fabricated by ultrasonic powder consolidation

2020 ◽  
Author(s):  
Ying Wang
2021 ◽  
Vol 21 (9) ◽  
pp. 4964-4967
Author(s):  
Bok-Hyun Oh ◽  
Choong-Hwan Jung ◽  
Heon Kong ◽  
Sang-Jin Lee

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.


2015 ◽  
Vol 825-826 ◽  
pp. 189-196 ◽  
Author(s):  
Maren Klement ◽  
Alwin Nagel ◽  
Oliver Lott

Composites with interpenetrating metal-ceramic microstructures (IPC, interpenetrating composites) can be tailored for specific applications, such as high thermal conductivity combined with low thermal expansion, e.g. for heat sinks. Heat sinks are required in power electronic devices or in future fusion reactor technology where extreme conditions and high cyclic thermo-mechanical loads appear. Due to its rigid ceramic backbone IPCs are expected to reveal high thermal stability. Pure silicon carbide exhibits high thermal conductivity, low coefficient of thermal expansion, high corrosion and wear resistance. But it is also known as a very brittle material when mechanical loads are applied. Thus a composite of silicon carbide with ductile and highly conductive copper seems to be a promising new material for a number of applications.This paper reports the synthesis of Cu-SiC composites using a unique high temperature squeeze casting process (HTSC). Microstructural design of SiC-preforms with open porosity and its synthesis progress is reported. Influence of preform properties, temperature, pressure and atmosphere during HTSC were investigated. A qualitative and quantitative description of the microstructure of the composites and their composition allows the creation of structure-property correlations that take effect retroactively to the casting process.


2011 ◽  
Vol 311-313 ◽  
pp. 287-292 ◽  
Author(s):  
Qiang Zuo ◽  
Wei Wang ◽  
Meng Sen Gu ◽  
Hai Jiang Fang ◽  
Li Ma ◽  
...  

The continuous progress of the electronic industries put forward a new requirement to the electronic components that must have an excellent heat conduction performance. Thus diamond-Cu composite is developed as a high thermal conductivity and low coefficient of thermal expansion material. A vacuum hot pressing method is chosen to prepare diamond-Cu composites and the thermal conductivity of the diamond-Cu composite is researched. The effects of different contents of chromium, the size of diamond particles and the content of diamond particles on the thermal conductivity of the diamond-Cu composite are discussed. The results demonstrate that the chromium element can improve the thermal conductivity of the composites and the thermal conductivity is largest when the content of chromium is 3 percent.


2019 ◽  
Author(s):  
Xingang Wang ◽  
Peng Cao

W-20wt.%Cu composite sheets with full density and good surface quality were successfully fabricated through an infiltration process followed by a hot rolling. After a total thickness reduction of 75%, the majority of the tungsten (W) particles have been deformed and elongated along the rolling direction. The aspect ratio of the W particles in the composite has reached 2.5. The relative density increases considerably to a maximum value of 99.8% when the rolling ratio increases. The thermal conductivity and microhardness of the W-Cu composites increase significantly with the rolling reduction. On the contrary, the coefficient of thermal expansion (CTE) of the composite samples decreases with the rolling ratio. Specifically, after subjected to 75% of thickness reduction, we obtained a large W-Cu thin sheet. This thin sheet demonstrates a low CTE of 7.27×10^-6/K and the highest thermal conductivity of 224.91 W/(m-K); both values are close to the respective theoretical ones.


2022 ◽  
Vol 60 (1) ◽  
pp. 68-75
Author(s):  
Bok-Hyun Oh ◽  
Chung-Il Ma ◽  
Ji-Yeon Kwak ◽  
Heon Kong ◽  
Sang-Jin Lee

A copper (Cu) metal-ceramic filler composite with high thermal conductivity and a suitable thermal expansion coefficient was designed for application as a high-performance heat dissipation material. The purpose of the designed material was to utilize the high thermal conductivity of Cu while lowering its high coefficient of thermal expansion by using a ceramic filler. In this study, a Cu-sol containing a certain amount of AlN or SiC ceramic filler was prepared using a non-aqueous solvent. A complex was produced by applying a PVB polymer to prepare a homogeneous precursor. The composite sintered without pressure in a reducing atmosphere showed low thermal conductivity due to residual pores, but the hot press sintered composite exhibited improved thermal conductivity. The Cu composite with 30 wt% AlN filler added exhibited a thermal conductivity of 290 W/m·K and a thermal expansion coefficient of 9.2 × 10-6/oC. Due to the pores in the composite, the thermal conductivity showed some difference from the theoretical value calculated from the rule of mixture. However, the thermal expansion coefficient did not show any significant difference.


Author(s):  
P.J. Huang ◽  
J.J. Swab ◽  
P.J. Patel ◽  
W.S. Chu

Abstract The development of thermal barrier coatings (TBCs) for diesel engines has been driven by the potential improvements in engine power and fuel efficiency that TBCs represent. TBCs have been employed for many years to reduce corrosion of valves and pistons because of their high temperature durability and thermal insulative properties. There are research programs to improve TBCs wear resistance to allow for its use in tribologically intensive areas of the engine. This paper will present results from tribological tests of ceria stabilized zirconia (CeSZ). The CeSZ was applied by atmospheric plasma spray process. Various mechanical and thermal properties were measured including wear, coefficient of thermal expansion, thermal conductivity, and microhardness. The results show the potential use of CeSZ in wear sensitive applications in diesel applications. Keywords: Thermal Barrier Coating, Diesel Engine, Wear, Thermal Conductivity, and Thermal Expansion


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