scholarly journals Improvement in Mechanical and Thermal Properties of Graphite Flake/Cu Composites by Introducing TiC Coating on Graphite Flake Surface

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 519 ◽  
Author(s):  
Ren Zhang ◽  
Xinbo He ◽  
Qian Liu ◽  
Xuanhui Qu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Hot Pressing ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Packaging Material ◽  
Graphite Flake ◽  
Mechanical And Thermal Properties ◽  
Electronic Packaging Material

In this work, TiC coating was successfully deposited on a graphite flake surface via molten salt technique, for the purpose of promoting the interfacial connection between Cu and graphite flake. Vacuum hot pressing was then employed to prepare TiC-coated graphite flake/Cu composite. The results indicate that introducing TiC coating on graphite flake surface can evidently reduce the pores and gaps at the interface, resulting in a significant improvement on the bending strength. When the TiC-coated graphite flake content is 60 vol%, the bending strength is increased by 58% compared with the uncoated one. The coefficient of thermal expansion dropped from 6.0 ppm·K−1 to 4.4 ppm·K−1, with the corresponding thermal conductivity as high as 571 W·m−1·K−1. The outstanding thermal conductivity, apposite coefficient of thermal expansion, as well as superior processability, make TiC-coated graphite flake/Cu composite a satisfactory electronic packaging material with vast prospect utilized in microelectronic industry.

Evaluation of CeSZ Thermal Barrier Coatings for Diesels

2000 ◽  
Author(s):  
P.J. Huang ◽  
J.J. Swab ◽  
P.J. Patel ◽  
W.S. Chu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Barrier Coatings ◽  
Coefficient Of Thermal Expansion ◽  
Fuel Efficiency ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Mechanical And Thermal Properties ◽  
Barrier Coatings ◽  
Spray Process

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

IMPROVEMENT OF MECHANICAL AND THERMAL PROPERTIES OF CFRP LAMINATES USING MICRO-FIBRILLATED CELLULOSE

2012 ◽  
Vol 06 ◽  
pp. 622-627 ◽  
Author(s):  
HYOJIN KIM ◽  
TADASHI SUZUKI ◽  
KENICHI TAKEMURA
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Thermal Properties ◽  
Carbon Fiber ◽  
Coefficient Of Thermal Expansion ◽  
Flexural Modulus ◽  
Mechanical And Thermal Properties ◽  
Flexural Test ◽  
Cfrp Laminates ◽  
Carbon Fiber Epoxy

The aim of this study is improvement of mechanical and thermal properties of plain woven carbon fiber (CF) reinforced epoxy with addition of MFC as the additive. Carbon fiber/epoxy laminates with addition 0.3, 0.5, 0.7 and 1wt% of MFC were characterized by flexural test, DSC and TMA. The result represented that the flexural strength improved slightly at 0.3 and 0.5 wt% of MFC, but flexural modulus was not changed, respectively. The glass transition temperature of MFC-CFRP laminates showed the increase according to increase of MFC addition at 0.7 and 1.0 wt%. The coefficient of thermal expansion was decrease by 0.7 wt% of MFC addition.

Influence of Chopped Fibre Length on the Mechanical and Thermal Properties of Silk Fibre-Reinforced Poly(Butylene Succinate) Biocomposites

2005 ◽  
Vol 13 (5) ◽  
pp. 479-488 ◽  
Author(s):  
Sang Muk Lee ◽  
Seong Ok Han ◽  
Donghwan Cho ◽  
Won Ho Park ◽  
Seung Goo Lee
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Coefficient Of Thermal Expansion ◽  
Fibre Length ◽  
Present System ◽  
Silk Fibre ◽  
Mechanical And Thermal Properties ◽  
Butylene Succinate ◽  
Linear Coefficient

The influence of chopped fibre length on the mechanical and thermal properties of silk fibre ( Bombix mori) reinforced poly(butylene succinate) (PBS) biocomposites has been investigated in terms of tensile and flexural properties, thermal stability, thermal expansion, and dynamic mechanical properties. The chopped fibre lengths studied were 3.2 mm, 6.4 mm, 12.7 mm, and 25.4 mm. The results demonstrate that chopped silk fibres play an effective role in improving the mechanical properties of PBS in the present system. At a fixed fibre loading of 40 wt%, the tensile strength and modulus of the PBS control were improved by 69% and 228%, respectively, in comparison with those of the biocomposite reinforced with 25.4 mm silk fibres. The flexural strength and modulus of PBS were also greatly improved by 167% and 323%, respectively. The thermal properties of PBS resin increased when incorporating chopped silk fibres in the composite matrix. The biocomposites had much lower linear coefficient of thermal expansion (CTE) values and higher storage moduli than the PBS controls above the glass transition region, especially with reinforcing silk fibres of 25.4 mm long.

scholarly journals Comparison of experimental and modelling results of thermal properties in Cu-AlN composite materials

2013 ◽  
Vol 61 (2) ◽  
pp. 507-514 ◽  
Author(s):  
M. Chmielewski ◽  
W. Weglewski
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Analytical Models ◽  
Matrix Composites ◽  
Pressing Method ◽  
3D Space ◽  
Automotive Electronic

Abstract Copper-based composites could be widely used in automotive, electronic or electrical industry due to their very promising thermal properties. In the present paper, Cu-AlN metal matrix composites with ceramic volume fractions between 0.1 and 0.4 were fabricated by hot pressing method in vacuum. Dependence of the coefficient of thermal expansion (CTE) and the thermal conductivity (TC) on the chemical composition of composites has been investigated. The measured values of the thermal expansion coefficient have been compared with the analytical models’ predictions. A numerical model based on FEAP 7.5 in 3D space has been used to evaluate the influence of the porosity on the thermal properties (thermal conductivity) of the composite. A fairly good correlation between the FEM results and the experimental measurements has been obtained.

scholarly journals Effect of Reinforcements on Mechanical and Thermal Properties of SiC Short-Fibre-Reinforced SiC Composites

2004 ◽  
Vol 13 (4) ◽  
pp. 096369350401300
Author(s):  
Jae-Seol Lee ◽  
Toyohiko Yano
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
High Temperatures ◽  
Hot Pressing ◽  
Fibre Type ◽  
Tape Casting ◽  
Mechanical And Thermal Properties ◽  
Sintering Additives ◽  
Short Fibres ◽  
Sic Composites

Tyranno SA fibre was higher strength at high temperatures and higher thermal conductivity than that of Hi-Nicalon fibre. Therefore, the aim of this study was to investigate the effect of reinforcements on the mechanical and thermal properties of SiC/SiC composites containing non-coated Tyranno SA short fibres. SiC/SiC composites containing 30 vol.% short fibres were fabricated by tape-casting and hot-pressing at 1650°C–1750°C under a pressure of 40 MPa using an Al2O3-Y2O3-CaO mixture as sintering additives independent of fibre type.

Improving mechanical and thermal properties of graphite–aluminium composite using Si, SiC and eggshell particles

2019 ◽  
Vol 54 (17) ◽  
pp. 2365-2376 ◽  
Author(s):  
MO Durowoju ◽  
TB Asafa ◽  
ER Sadiku ◽  
S Diouf ◽  
MB Shongwe ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Relative Density ◽  
Coefficient Of Thermal Expansion ◽  
Mechanical And Thermal Properties ◽  
Sem Images ◽  
Plasma Sintering ◽  
Low Thermal Expansion ◽  
Spark Plasma

Graphite–aluminium (Gr–Al) composites are being used for diverse engineering applications because of their light weight, good electrical conductivity and thermal properties. However, their applications are limited by high coefficient of thermal expansion and low microhardness values which can be enhanced by adding cheap and efficient fillers. This paper reports the effect of addition of eggshell (ES) particles on the properties of sintered Gr–Al-based composites. Five different composites (Gr–Al, Gr–Al  +  20 wt.%Si, Gr–Al + 20 wt.%SiC, Gr–Al + 20Si wt.% + 20 wt.%ES and Gr–Al + 20SiC wt.% + 20 wt.%ES) were sintered at a temperature of 540 ℃, holding time of 10 min, heating rate of 52 ℃/min and pressure of 50 MPa using spark plasma sintering system. The sintered samples were characterized based on morphology, microhardness, relative density, coefficient of thermal expansion and electrical conductivity. Based on SEM images, graphite particles of flake-like structure were largely undeformed while Al particles were smaller, round and irregular in shape and fairly uniformly distributed in the composites. The microhardness value of sintered Gr–Al + 20 wt.%SiC + 20 wt.%ES composite was 39.55 HV compared to 30.46 HV for Gr–Al, the least of the samples. The Gr–Al + 20 wt.%SiC + 20 wt.%ES composite also has a very low thermal expansion coefficient (0.98 × 10−5/K) but lowest electrical conductivity at temperature beyond 150 ℃. Highest densification and minimum relative density (94%) were obtained in Gr–Al + 20 wt.%Si + 20 wt.%ES composite. These enhanced performances are largely due to the incorporation of ES particles. This study therefore demonstrated that ESs particles enhanced microhardness and lowered thermal expansion of Gr–Al-based composites which have promising applications in industries especially for thermal management.

scholarly journals Mechanical and thermal properties of tungsten carbide – graphite nanoparticles nanocomposites

2016 ◽  
Vol 18 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Kamil Kornaus ◽  
Agnieszka Gubernat ◽  
Dariusz Zientara ◽  
Paweł Rutkowski ◽  
Ludosław Stobierski
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Tungsten Carbide ◽  
Bending Strength ◽  
Polycrystalline Materials ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Pure Tungsten ◽  
Graphite Nanoparticles

Abstract Previous studies concerning pure tungsten carbide polycrystalline materials revealed that nanolayers of graphite located between WC grains improve its thermal properties. What is more, pressure-induced orientation of graphene nano platelets (GNP) in hot pressed silicon nitride-graphene composites results in anisotropy of thermal conductivity. Aim of this study was to investigate if addition of GNP to WC will improve its thermal properties. For this purpose, tungsten carbide with 0.5–6 wt.% of GNP(12)-additive underwent hot pressing. The microstructure observations performed by SEM microscopy. The anisotropy was determined via ultrasonic measurements. The following mechanical properties were evaluated: Vickers hardness, bending strength, fracture toughness KIc. The influence of GNP(12) addition on oxidation resistance and thermal conductivity was examined. It was possible to manufacture hot-pressed WC-graphene composites with oriented GNP(12) particles, however, the addition of graphene decreased both thermal and mechanical properties of the material.

scholarly journals Current Status of Research on the Modification of Thermal Properties of Epoxy Resin-Based Syntactic Foam Insulation Materials

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3185
Author(s):  
Zhongyuan Zhang ◽  
Xiaohan Dai ◽  
Le Li ◽  
Songsong Zhou ◽  
Wei Xue ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Epoxy Resin ◽  
Coefficient Of Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Syntactic Foam ◽  
Research Field ◽  
Current Status ◽  
Insulation Materials

As a lightweight and highly insulating composite material, epoxy resin syntactic foam is increasingly widely used for insulation filling in electrical equipment. To avoid core burning and cracking, which are prone to occur during the casting process, the epoxy resin-based syntactic foam insulation materials with high thermal conductivity and low coefficient of thermal expansion are required for composite insulation equipment. The review is divided into three sections concentrating on the two main aspects of modifying the thermal properties of syntactic foam. The mechanism and models, from the aspects of thermal conductivity and coefficient of thermal expansion, are presented in the first part. The second part aims to better understand the methods for modifying the thermal properties of syntactic foam by adding functional fillers, including the addition of thermally conductive particles, hollow glass microspheres, negative thermal expansion filler and fibers, etc. The third part concludes by describing the existing challenges in this research field and expanding the applicable areas of epoxy resin-based syntactic foam insulation materials, especially cross-arm composite insulation.

scholarly journals Effects of Zr-Cu Alloy Powder on Microstructure and Properties of Cu Matrix Composite with Highly-Aligned Flake Graphite

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5709
Author(s):  
Cunguang Chen ◽  
Qianyue Cui ◽  
Chengwei Yu ◽  
Pei Li ◽  
Weihao Han ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Alloy Powder ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Tape Casting ◽  
Strain Engineering ◽  
Flake Graphite ◽  
Cu Alloy ◽  
Pure Cu

Highly-aligned flake graphite (FG) reinforced Cu matrix composites with high thermal conductivity and adaptive coefficient of thermal expansion were successfully prepared via the collaborative process of tape-casting and hot-pressing sintering. To overcome the problem of fragile interface, Zr-Cu alloy powder was introduced instead of pure Zr powder to enhance the interfacial strength, ascribed to the physical-chemical bonding at the Cu-FG interface. The results indicate that the synthetic ZrC as interfacial phase affects the properties of FG/Cu composites. The thermal conductivity reaches the maximum value of 608.7 W/m∙K (52% higher than pure Cu) with 0.5 wt % Zr. Surprisingly, the negative coefficient of thermal expansion (CTE) in the Z direction is acquired from −7.61 × 10−6 to −1.1 × 10−6/K with 0 to 2 wt % Zr due to the physical mechanism of strain-engineering of the thermal expansion. Moreover, the CTE in X-Y plane with Zr addition is 8~10 × 10−6/K, meeting the requirements of semiconductor materials. Furthermore, the bending strength of the FG/Cu-2 wt % Zr composite is 42% higher than the FG/Cu composite. Combining excellent thermal conductivity with ultralow thermal expansion make the FG/Cu-Zr composites be a highly promising candidate in the electronic packaging field.

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