scholarly journals Influence of Material Coating on the Heat Transfer in a Layered Cu-SiC-Cu Systems

2017 ◽  
Vol 62 (2) ◽  
pp. 1311-1314
Author(s):  
A. Strojny-Nędza ◽  
K. Pietrzak ◽  
M. Teodorczyk ◽  
M. Basista ◽  
W. Węglewski ◽  
...  

AbstractThis paper describes the process of obtaining Cu-SiC-Cu systems by way of spark plasma sintering. A monocrystalline form of silicon carbide (6H-SiC type) was applied in the experiment. Additionally, silicon carbide samples were covered with a layer of tungsten and molybdenum using chemical vapour deposition (CVD) technique. Microstructural examinations and thermal properties measurements were performed. A special attention was put to the metal-ceramic interface. During annealing at a high temperature, copper reacts with silicon carbide. To prevent the decomposition of silicon carbide two types of coating (tungsten and molybdenum) were applied. The effect of covering SiC with the aforementioned elements on the composite’s thermal conductivity was analyzed. Results were compared with the numerical modelling of heat transfer in Cu-SiC-Cu systems. Certain possible reasons behind differences in measurements and modelling results were discussed.

2017 ◽  
Vol 62 (2) ◽  
pp. 1315-1318 ◽  
Author(s):  
M. Chmielewski ◽  
K. Pietrzak ◽  
A. Strojny-Nędza ◽  
D. Jarząbek ◽  
S. Nosewicz

AbstractThis paper analyses the technological aspects of the interface formation in the copper-silicon carbide composite and its effect on the material’s microstructure and properties. Cu-SiC composites with two different volume content of ceramic reinforcement were fabricated by hot pressing (HP) and spark plasma sintering (SPS) technique. In order to protect SiC surface from its decomposition, the powder was coated with a thin tungsten layer using plasma vapour deposition (PVD) method. Microstructural analyses provided by scanning electron microscopy revealed the significant differences at metal-ceramic interface. Adhesion force and fracture strength of the interface between SiC particles and copper matrix were measured. Thermal conductivity of composites was determined using laser flash method. The obtained results are discussed with reference to changes in the area of metal-ceramic boundary.


2014 ◽  
Vol 722 ◽  
pp. 25-29 ◽  
Author(s):  
Q.L. Che ◽  
X.K. Chen ◽  
Y.Q. Ji ◽  
Y.W. Li ◽  
L.X. Wang ◽  
...  

The carbide forming is proposed to improve interfacial bonding between diamond particles and copper-matrix for diamond/copper composites. The volume fraction of diamond and minor titanium are optimized. The microstructures, thermal properties, interface reaction production and its effect of minor titanium on the properties of the composites are investigated. The results show that the bonding force and thermal conductivity of the diamond/Cu-Ti alloys composites is much weaker and lower than that of the coated-diamond/Cu. the thermal conductivity of coated-60 vol. % diamond/Cu composites is 618 W/m K which is 80 % of the theoretical prediction value. The high thermal conductivity has been achieved by forming the titanium carbide at diamond/copper interface to gain a good interface.


2018 ◽  
Vol 50 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Nouari Saheb ◽  
Muhammad Khan

In this work, compressive and thermal properties of aluminum, milled aluminum, and Al-10Al2O3 composite processed via ball milling (BM) and spark plasma sintering (SPS) were investigated. The microstructural features of powders and sintered samples were characterized using optical and scanning electron microscopy. A universal testing machine was used to determine the compressive properties of the consolidated samples. The thermal conductivity and coefficient of thermal expansion of the developed materials were characterized using a hot disc thermal constant analyzer and a dilatometer, respectively. The Al-10Al2O3 composite possessed hardness of 1309.7 MPa, yield strength of 311.4 MPa, and compressive strength of 432.87 MPa compared to hardness of 326.3 MPa, yield strength of 74.33 MPa, and compressive strength of 204.43 MPa for aluminum. The Al-10Al2O3 composite had thermal conductivity value 81.42 W/mK compared to value of 198.09 W/mK for aluminum. In the temperature range from 373 K to 723 K, the composite had lower CTEs ranging from 10 ? 10?6 to 22 ? 10?6/K compared to 20 ? 10?6 to 30 ? 10?6/K for aluminum.


2015 ◽  
Vol 655 ◽  
pp. 11-16 ◽  
Author(s):  
Xing Li Liu ◽  
Meng Meng Peng ◽  
Xiao Shan Ning ◽  
Yosuke Takahashi

To investigate the influence of β-Si3N4 powder on thermal conductivity of silicon nitride, coarse, fine β-Si3N4 powder and various β-Si3N4/α-Si3N4 ratios of starting powders were adopted to fabricate ceramics by spark plasma sintering at 1600°Cand subsequent high-temperature heat treatment at 1900°C with the sintering additives of Y2O3 and MgO. It is found that with more fine β-Si3N4 powder in the starting powder, β-Si3N4 grains exhibit high thermal conductivity, which is partly resulted from the compaction of β-Si3N4 grains.


2010 ◽  
Vol 638-642 ◽  
pp. 2115-2120 ◽  
Author(s):  
Kiyoshi Mizuuchi ◽  
Kanryu Inoue ◽  
Yasuyuki Agari ◽  
Shinji Yamada ◽  
Motohiro Tanaka ◽  
...  

Diamond-particle-dispersed copper (Cu) matrix composites were fabricated from Cu-coated diamond particles by spark plasma sintering (SPS) process, and the microstructure and thermal properties of the composites fabricated were examined. These composites can well be consolidated in a temperature range between 973K and 1173K and scanning electron microscopy detects no reaction at the interface between the diamond particle and the Cu matrix. The relative packing density of the diamond-Cu composite increases with increasing sintering temperature and holding time, reaching 99.2% when sintered at a temperature of 1173K for a holding time of 2.1ks. Thermal conductivity of the diamond-Cu composite containing 43.2 vol. % diamond increases with increasing relative packing density, reaching a maximum (654W/mK) at a relative packing density of 99.2%. This thermal conductivity is 83% the theoretical value estimated by Maxwell-Eucken equation. The coefficient of thermal expansion of the composites falls in the upper line of Kerner’s model, indicating strong bonding between the diamond particle and the Cu matrix in the composite.


2006 ◽  
Vol 527-529 ◽  
pp. 575-578 ◽  
Author(s):  
Reino Aavikko ◽  
Kimmo Saarinen ◽  
Björn Magnusson ◽  
Erik Janzén

Positron annihilation radiation Doppler broadening spectroscopy was used to study defects in semi-insulating (SI) silicon carbide (SiC) substrates grown by high-temperature chemical vapour deposition (HTCVD). The Doppler broadening measurements show (i) that the measured samples contain vacancy clusters (ii) that the positron trapping to the clusters is increased in annealing (iii) that the chemical environment of the defects in the un-annealed samples is different from those of the annealed samples.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4768
Author(s):  
Sheng Ge ◽  
Xiumin Yao ◽  
Yingying Liu ◽  
Hang Duan ◽  
Zhengren Huang ◽  
...  

Silicon carbide (SiC) ceramics with Y2O3-Er2O3 as sintering additives were prepared by spark plasma sintering (SPS). The effects of sintering temperatures and Y2O3-Er2O3 contents on the microstructure, thermal conductivity, electrical, and mechanical properties were investigated. The increasing of sintering temperatures promoted the densification of SiC ceramics, thus increasing the thermal conductivity and electrical resistivity. With the increase of the sintering additive contents, the electrical resistivity increased due to the formation of the electrical insulating network; and the thermal conductivity first increased and then decreased, which was related to the content and distribution of the secondary phase among the SiC grains. The SiC ceramics sintered at 2000 °C with 9 wt.% Y2O3-Er2O3 exhibited higher electrical resistivity and thermal conductivity, which were 4.28 × 109 Ω·cm and 96.68 W/m·K, respectively.


2018 ◽  
Vol 913 ◽  
pp. 803-810 ◽  
Author(s):  
Wen Qiang Ma ◽  
Cheng Jie Deng ◽  
Jin Le Lan ◽  
Xiao Ping Yang ◽  
Yuan Hua Lin

Polycrystalline Bi1-xCuSeO (0 ≤ x ≤ 0.05) ceramics were prepared by self-propagating high-temperature synthesis followed by spark plasma sintering method. All the samples correspond with single BiCuSeO phase and high vacancies sample had higher density. The highest power factor of 4.71×10-4 W.m-1.K-2 was obtained by 5% Bi vacancies at 873K, which is about 32% higher than that of the pristine sample. Along with slight reduction of thermal conductivity, the maximum ZT reached 0.68. The results show that vacancy engineering is a promising method for thermoelectric applications of BiCuSeO and related ceramics.


Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Shi Tian ◽  
Zelin Liao ◽  
Wenchao Guo ◽  
Qianglong He ◽  
Heng Wang ◽  
...  

TiB2-BN composite ceramics combine excellent electrical conductivity, thermal shock resistance, high-temperature resistance, corrosion resistance, and easy processing of TiB2 and BN. However, in practical applications, their high-temperature oxidation resistance is poor and the resistivity distribution is uneven and changes substantially with temperature. A TiB2-BN-SiC composite ceramic with stable and controllable resistivity was prepared by introducing SiC into the TiB2-BN composite ceramics. In this work, spark plasma sintering (SPS) technology was used to prepare TiB2-BN-SiC composite ceramics with various TiB2-SiC ratios and sintering temperatures. The samples were tested by XRD, SEM, and thermal and mechanical analysis. The results show that as the volume ratio of TiB2-SiC was increased from 3:1 to 12:1, the resistivity of the sample decreased from 8053.3 to 4923.3 μΩ·cm, the thermal conductivity increased from 24.89 to 34.15 W/(m k), and the thermal expansion rate increased from 7.49 (10−6/K) to 10.81 (10−6/K). As the sintering temperature was increased from 1650 to 1950 °C, the density of the sample increased, the mechanical properties were slightly improved, and the resistivity, thermal expansion rate, and thermal conductivity changed substantially. The volume ratio and sintering temperature are the key factors that control the resistivity and thermal characteristics of TiB2-SiC-BN composite ceramics, and the in situ from liquid phases of FeB and FeO also promotes the sintering of the TiB2-BN-SiC ceramics.


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