Synthesis of Copper/Silicon-Carbide Composites in a Thermodynamic Disequilibrium

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.

Author(s):  
S A Mohan Krishna ◽  
T N Shridhar ◽  
L Krishnamurthy ◽  
K B Vinay ◽  
G V Naveen Prakash

Aluminium matrix composites belong to the family of materials whose mechanical, tribological, thermal and electrical properties can be customized effectively. Most of the commercial work on MMCs has been highlighted on Aluminium as the matrix material. The combination of light weight, environmental resistance and beneficial mechanical properties has made Aluminium alloys exceedingly popular; these properties also make Aluminium best suited for use as a matrix metal. The thermophysical properties of these composites can be tailor made and have excellent specific mechanical properties. These composites can be fabricated with ease. Aluminium matrix composites reinforced with the particles of Silicon Carbide possess high yield strength, low coefficient of thermal expansion or thermal expansivity, high modulus of elasticity and excellent wear resistance by maintaining volume proportion up to 20%. Aluminium hybrid composites can be customized to provide moderate Coefficient of Thermal Expansion (CTE) and high thermal conductivity that are favorable for the applications pertaining to thermal management equipment. However, it is necessary to evaluate different percentage combinations of reinforcements with matrix Aluminium to check for thermal stability and to measure thermal conductivity and coefficient of thermal expansion. It is expected that, Aluminium-Silicon Carbide-Graphite hybrid composites can be used as load bearing material for the above applications. In this paper, a review about the said hybrid composites to investigate thermal properties for engineering applications have been discussed based on its technological relevance, applications and research prospect.


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.


2013 ◽  
Vol 795 ◽  
pp. 237-240
Author(s):  
K. Azmi ◽  
M.N. Derman ◽  
Mohd Mustafa Al Bakri Abdullah

The demand for advanced thermal management materials such as silicon carbide reinforced copper matrix (Cu-SiCp) composites is increasing due to their high thermal conductivity and low CTE properties. However, the weak bonding between the copper matrix and the SiCp reinforcement degrades the thermophysical properties of the composites. In order to improve the bonding between the two constituents, the SiCp were copper coated (Cu-Coated) via electroless coating process. Based on the experimental results, the CTE values of the Cu-Coated Cu-SiCp composites were found significantly lower than those of the non-Coated Cu-SiCp composites. The CTEs of the Cu-Coated Cu-SiCp composites were in agreement with Kernels model which accounts for both the shear and isostatic stresses developed in the component phases.


1995 ◽  
Vol 390 ◽  
Author(s):  
Chris H. Stoessel ◽  
C. Pan ◽  
J. C. Withers ◽  
D. Wallace ◽  
R. O. Loutfy

ABSTRACTHigh thermal conductivity heat sinks for thermal management in electronic packaging is enabling to a variety of advanced electronic applications. Heat sinks in industrial semiconductor application have thermal conductivities generally less than 180 W/mK, and frequently have large expansion mismatch with chips such as silicon and gallium arsenide. A unique technology of producing graphite fiber reinforced copper (Cf/Cu) composite has been developed that produced thermal conductivities up to 454 W/mK utilizing a K=640 W/mK fiber reinforcement (with a potential for 800 W/mK when utilizing a K = 1100 W/mK P130 fiber) and thermal expansion that can be matched to chip materials. The process consists of utilizing a hollow cathode sputtering process to deposit a bonding layer followed by copper on spread graphite fibers, which are then consolidated into composites with architectures to achieve desired thermal conductivity and thermal expansion. The copper thickness determines graphite fiber loading up to 80 %. In heat sink applications, where the electrical conductivity of the graphite fiber reinforced copper composite is a problem, processing has been developed for applying electrically insulating diamond film, which has high thermal conductivity and acts as a heat spreader.


2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000207-000215 ◽  
Author(s):  
A. A. Wereszczak ◽  
M. C. Modugno ◽  
S. B. Waters ◽  
D. J. DeVoto ◽  
P. P. Paret

Abstract The use of sintered-silver for large-area interconnection is attractive for some large-area bonding applications in power electronics such as the bonding of metal-clad, electrically-insulating substrates to heat sinks. Arrays of different pad sizes and pad shapes have been considered for such large area bonding; however, rather than arbitrarily choosing their size, it is desirable to use the largest size possible where the onset of interconnect delamination does not occur. If that is achieved, then sintered-silver's high thermal and electrical conductivities can be fully taken advantage of. Toward achieving this, a simple and inexpensive proof test is described to identify the largest achievable interconnect size with sinterable silver. The method's objective is to purposely initiate failure or delamination. Copper and invar (a ferrous-nickel alloy whose coefficient of thermal expansion (CTE) is similar to that of silicon or silicon carbide) disks were used in this study and sinterable silver was used to bond them. As a consequence of the method's execution, delamination occurred in some samples during cooling from the 250°C sintering temperature to room temperature and bonding temperature and from thermal cycling in others. These occurrences and their interpretations highlight the method's utility, and the herein described results are used to speculate how sintered-silver bonding will work with other material combinations.


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.


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.


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