On the thermal expansion of composite materials and cross-property connection between thermal expansion and thermal conductivity

2012 ◽  
Vol 45 ◽  
pp. 20-33 ◽  
Author(s):  
Igor Sevostianov
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Composite Materials

Friction and Wearing Behaviour of Sintered Composites Made from Copper Mixed with Carbon Fibers

2015 ◽  
Vol 660 ◽  
pp. 81-85 ◽  
Author(s):  
Radu Caliman
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Friction Coefficient ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Coefficient Of Thermal Expansion ◽  
Density Ratio ◽  
Point Of View ◽  
Short Carbon

This paper presents a study regarding friction and wear comportment of sintered composite materials obtained by mixture of copper with short carbon fibers. Sintered composites are gaining importance because the reinforcement serves to reduce the coefficient of thermal expansion and increase the strength and modulus. In case of composites form by carbon fiber and copper, the thermal conductivity can also be enhanced. The combination of low thermal expansion and high thermal conductivity makes them very attractive for electronic packaging. Besides good thermal properties, their low density makes them particularly desirable for aerospace electronics and orbiting space structures. Compared to the metal itself, a carbon fiber-copper composite is characterized by a higher strength-to-density ratio, a higher modulus-to-density ratio, better fatigue resistance, better high-temperature mechanical properties and better wear resistance. Varying the percentage of short carbon fibers from 7,8% to 2,4%, and the percentage of copper from 92,2% to 97,6%, five dissimilar composite materials have been made and tested from the wear point of view. Friction tests are carried out, at room temperature, in dry conditions, on a pin-on-disc machine. The friction coefficient was measured using abrasive discs made from steel 4340 having the average hardness of 40 HRC, and sliding velocity of 0,6 m/sec. The primary goal of this study work it was to distinguish a mixture of materials with enhanced friction and wearing behaviour. The load applied on the specimen during the tests, is playing a very important role regarding friction coefficient and also the wearing speed.

scholarly journals Thermal and Flame Retardant Behavior of Neem and Banyan Fibers When Reinforced with a Bran Particulate Epoxy Hybrid Composite

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3859
Author(s):  
Thandavamoorthy Raja ◽  
Vinayagam Mohanavel ◽  
Thanikodi Sathish ◽  
Sinouvassane Djearamane ◽  
Palanivel Velmurugan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Flame Retardant ◽  
Hybrid Composite ◽  
Thermal Testing ◽  
Short Term ◽  
Maximum Heat ◽  
Fiber Loading ◽  
Heat Deflection Temperature

Awareness of environmental concerns influences researchers to develop an alternative method of developing natural fiber composite materials, to reduce the consumption of synthetic fibers. This research attempted testing the neem (Azadirachta indica) fiber and the banyan (Ficus benghalensis) fiber at different weight fractions, under flame retardant and thermal testing, in the interest of manufacturing efficient products and parts in real-time applications. The hybrid composite consists of 25% fiber reinforcement, 70% matrix material, and 5% bran filler. Their thermal properties—short-term heat deflection, temperature, thermal conductivity, and thermal expansion—were used to quantify the effect of potential epoxy composites. Although natural composite materials are widely utilized, their uses are limited since many of them are combustible. As a result, there has been a lot of focus on making them flame resistant. The thermal analysis revealed the sample B was given 26% more short-term heat resistance when the presence of banyan fiber loading is maximum. The maximum heat deflection temperature occurred in sample A (104.5 °C) and sample B (99.2 °C), which shows a 36% greater thermal expansion compared with chopped neem fiber loading. In sample F, an increased chopped neem fiber weight fraction gave a 40% higher thermal conductivity, when compared to increasing the bidirectional banyan mat of this hybrid composite. The maximum flame retardant capacity occurred in samples A and B, with endurance up to 12.9 and 11.8 min during the flame test of the hybrid composites.

Processing and Thermal Properties of Cu-AlN Composites

2010 ◽  
Vol 65 ◽  
pp. 100-105 ◽  
Author(s):  
Marcin Chmielewski ◽  
Katarzyna Pietrzak ◽  
Dariusz Kaliński ◽  
Agata Strojny
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Coefficient Of Thermal Expansion ◽  
Processing Parameters ◽  
Process Conditions ◽  
Pressing Method ◽  
Materials Used ◽  
Effective Transfer

Heat transfer by conduction is involved in the use of heat sinks dissipitating heat from electronic devices. Effective transfer of heat requires using materials of high thermal conductivity. In addition, it requires appropriate values of thermal expansion, matched to the semiconductor materials, high purity of materials used and good contact between bonded elements across which heat transfer occurs. The conventional materials are not able to fulfil still raising and complex requirements. The solutions of this problem could be using the composites materials, where the combinations of different properties is possible to use. This study presents the technological tests and the analysis of correlation between processing parameters and the properties of copperaluminium nitride composites. Composite materials were obtained by mixing in planetary ball mill and then densified using the sintering under pressure or hot pressing method. The microstructure of obtained composite materials using optical microscopy and scanning electron microscopy were analyzed. Coefficient of thermal expansion (CTE) and thermal conductivity (TC) were investigated depending on the process conditions.

Thermal Conductivity of Composite Materials Having a Chaotic Structure

2004 ◽  
Vol 35 (7-8) ◽  
pp. 507-515
Author(s):  
V. V. Novikov ◽  
A. N. Piven' ◽  
L. N. Udovenko
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials

scholarly journals Thermal conductivity of composite materials in the range from 7 to 80 K used in cryogenic engineering

2021 ◽  
Vol 1889 (4) ◽  
pp. 042005
Author(s):  
A F Brodnikov ◽  
A V Bragin ◽  
N A Vichareva ◽  
F P Kazantsev ◽  
V I Kondratyev
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Cryogenic Engineering

Enhanced Effective Thermal Conductivity of Composite Materials by Incorporating Constructal Fillers

2021 ◽  
Vol 42 (7) ◽  
Author(s):  
Xiaojian Wang ◽  
Xiaohu Niu ◽  
Wensheng Kang ◽  
Xiaoxue Wang ◽  
Liangbi Wang
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Effective Thermal Conductivity

scholarly journals Optimization of the composition in a composite material for microelectronics application using the Ising model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshihiko Imanaka ◽  
Toshihisa Anazawa ◽  
Fumiaki Kumasaka ◽  
Hideyuki Jippo
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Ising Model ◽  
Specific Gravity ◽  
Simulated Annealing Algorithm ◽  
Optimization Problems ◽  
Industrial Applications ◽  
Thermal Dissipation ◽  
Materials Informatics ◽  
Combinatorial Optimization Problems

AbstractTailored material is necessary in many industrial applications since material properties directly determine the characteristics of components. However, the conventional trial and error approach is costly and time-consuming. Therefore, materials informatics is expected to overcome these drawbacks. Here, we show a new materials informatics approach applying the Ising model for solving discrete combinatorial optimization problems. In this study, the composition of the composite, aimed at developing a heat sink with three necessary properties: high thermal dissipation, attachability to Si, and a low weight, is optimized. We formulate an energy function equation concerning three objective terms with regard to the thermal conductivity, thermal expansion and specific gravity, with the composition variable and two constrained terms with a quadratic unconstrained binary optimization style equivalent to the Ising model and calculated by a simulated annealing algorithm. The composite properties of the composition selected from ten constituents are verified by the empirical mixture rule of the composite. As a result, an optimized composition with high thermal conductivity, thermal expansion close to that of Si, and a low specific gravity is acquired.

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