Effects of Particle Size on the Thermal Physical Properties of SiCp/Al Composites

2007 ◽  
Vol 351 ◽  
pp. 131-134 ◽  
Author(s):  
Lin Geng ◽  
Yi Wu Yan
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Thermal Expansion ◽  
Room Temperature ◽  
Thermal Loading ◽  
Thermal Residual Stresses ◽  
Powder Metallurgy Process ◽  
The Difference ◽  
Metallurgy Process ◽  
Thermal Physical Properties

The coefficients of thermal expansion (CTEs) of the 20 vol% SiCp/Al composites fabricated by powder metallurgy process were measured and examined from room temperature to 450°C The SiC particles are in three nominal sizes 5μm, 20μm and 56μm. The CTEs of the SiCp/Al composites were shown to be apparently dependent on the particle size. That the larger particle size, the higher CTEs of the composites, is thought to be due to the difference in original thermal residual stresses and matrix plasticity during thermal loading. The thermal conductivity of the composites also increases with particle size increasing.

Preparation and Properties Study of Cu-MoSi2 Composites

2007 ◽  
Vol 534-536 ◽  
pp. 581-584 ◽  
Author(s):  
Xiaoou Yi ◽  
Wei Hao Xiong ◽  
Jian Li
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Mechanical And Thermal Properties ◽  
Matrix Composites ◽  
Thermal Expansion Coefficients ◽  
Low Thermal Expansion ◽  
Powder Metallurgy Process ◽  
Expansion Coefficients ◽  
Metallurgy Process

The particulate dispersive strengthened Cu-MoSi2 composites were prepared by a powder metallurgy process with aim to develop novel copper based composites of reasonable strength, high thermal conductivity and low thermal expansion coefficients. Compacted samples were sintered to over 90% of theoretical density. Microstructure of the composites was investigated by SEM while mechanical properties such as tensile strength, elongation and thermal properties such as thermal conductivity and thermal expansion coefficient (CTE) of the composites were examined as a function of the MoSi2 content and the process of fabrication. A comparative analysis of the mechanical and thermal properties of various Cu-matrix composites currently in use was given and the strengthening mechanisms for the Cu-MoSi2 composites were discussed.

scholarly journals Opening Material as the Possibility of Elimination Veining in Foundries

2016 ◽  
Vol 16 (3) ◽  
pp. 157-161 ◽  
Author(s):  
M. Hrubovčáková ◽  
I. Vasková ◽  
M. Benková ◽  
M. Conev
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Thermal Expansion ◽  
Cast Iron ◽  
Granular Material ◽  
Surface Defects ◽  
Silica Sand ◽  
Iron Castings ◽  
Thermal Dilatation

Abstract The main bulk density representation in the molding material is opening material, refractory granular material with a particle size of 0.02 mm. It forms a shell molds and cores, and therefore in addition to activating the surface of the grain is one of the most important features angularity and particle size of grains. These last two features specify the porosity and therefore the permeability of the mixture, and thermal dilatation of tension from braking dilation, the thermal conductivity of the mixture and even largely affect the strength of molds and cores, and thus the surface quality of castings. [1] Today foundries, which use the cast iron for produce of casts, are struggling with surface defects on the casts. One of these defects are veining. They can be eliminated in several ways. Veining are foundry defects, which arise as a result of tensions generated at the interface of the mold and metal. This tension also arises due to abrupt thermal expansion of silica sand and is therefore in the development of veining on the surface of casts deal primarily influences and characteristics of the filler material – opening material in the production of iron castings.

Effect of Anisotropy on The Thermoelectric Properties of Bi1Sb3Te6 Added with Au Alloys Prepared by Mechanical Alloying Process

2006 ◽  
Vol 321-323 ◽  
pp. 1360-1364
Author(s):  
Wang Kee Min ◽  
Chang Ho Lee ◽  
Yong Ho Park ◽  
Ik Min Park
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Powder Metallurgy Process ◽  
Parallel Direction ◽  
Z Value ◽  
Metallurgy Process ◽  
Conduction Properties

An effect of anisotropy on the thermoelectric properties of Bi1Sb3Te6 added with Au alloys prepared by a mechanical alloying process has been studied. The conduction properties including electrical conductivity and thermal conductivity were increased with Au content. The electrical conductivity and the power factor of the perpendicular direction to the pressing direction were larger than those of the parallel direction to the pressing direction. The intensity of (1 1 0) perpendicular plane was larger than that of the parallel plane. It was suggested that the increase of intensity of the (1 1 0) plane would contribute to improve the thermoelectric performance. Although the power factor and thermal conductivity revealed the anisotropic behavior with direction, the Z value showed almost the equal value regardless of direction. From these results, it appeared that the Z value of the Bi1Sb3Te6 added with Au alloy prepared by powder metallurgy process was almost isotropic.

Research of Thermal Conductivity and Tensile Strength of Carbon Black-Filled Nature Rubber

2009 ◽  
Vol 87-88 ◽  
pp. 200-205 ◽  
Author(s):  
Yan He ◽  
Zhong Yin ◽  
Lian Xiang Ma ◽  
Jun Ping Song
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Tensile Strength ◽  
Carbon Black ◽  
Volume Fraction ◽  
Carbon Black Particle ◽  
Black Particle ◽  
The Difference ◽  
Thermal Conductivities

Through measuring the thermal conductivities and tensile strength of nature rubbers filled with carbon black and comparing with each other, it is shown that the difference of carbon black particle size and the structure affects on the thermal conductivity and tensile strength of nature rubber. Thermal conductivities of carbon black-filled nature rubber are enhanced with the increase of volume fraction of filler; tensile strength of composite increases first and then decreases with the increase of carbon black volume fraction.

Effects of Particle Size on Microstructures and Properties of Si/Al Composites

2013 ◽  
Vol 873 ◽  
pp. 361-365 ◽  
Author(s):  
Wei Chen Zhai ◽  
Zhao Hui Zhang ◽  
Fu Chi Wang ◽  
Shu Kui Li
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Thermal Expansion ◽  
Flexural Strength ◽  
Spark Plasma Sintering ◽  
Thermal Conductivity Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
High Strength ◽  
Plasma Sintering ◽  
Spark Plasma

Si/Al composites with different Si particle sizes were fabricated using spark plasma sintering process for electronic packaging. The density, thermal conductivity, coefficient of thermal expansion and flexural strength of the composites were investigated. Effect of Si particle size on structure and properties of the Si/Al composites were studied. The results showed that the Si/Al composites synthesized by spark plasma sintering were composed of Si and Al. Al was uniformly distributed among the Si phase, leading to a high thermal conductivity (>120 W/m·k). The relative density of the Si/Al composites decreased with increasing Si particle size. Small Si particle size produced small grains, leading to a low coefficient of thermal expansion and a high strength. There is an optimal matching among the thermal conductivity, coefficient of thermal expansion and flexural strength when the Si particle size was 44 um.

Computational Design and Development of Alumina-Nickel Droplet Composites

2016 ◽  
Author(s):  
S. Sohail Akhtar ◽  
A. F. M. Arif ◽  
M. U. Siddiqui ◽  
Kabeer Raza ◽  
L. Taiwo Kareem ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Volume Fraction ◽  
Matrix Material ◽  
Microstructural Analysis ◽  
Computational Design ◽  
Minimum Size

Computational design for property management of composite materials offers a cost sensitive alternate approach in order to understand the mechanisms involved in the thermal and structural behavior of material under various combinations of inclusions and matrix material. The present study is concerned with analyzing the elasto-plastic and thermal behavior of Al2O3-Ni droplet composites using a mean field homogenization and effective medium approximation (EMA) using an in-house code. Our material design approach relies on a method for predicting potential optimum thermal and structural properties for Al2O3-Ni composites by considering the effect of inclusion orientation, volume, size, thermal interface resistance, percolation and porosity. The primary goal for designing such alumina-based composites is to have enhanced thermal conductivity for effective heat dissipation and spreading capabilities. At the same time, other functional properties like thermal expansion coefficient, elastic modulus, and electrical resistivity have to be maintained or enhanced. The optimum volume fraction was found to occur between 15 and 20 vol. %Ni while the average nickel particle size of 5 μm was found a minimum size that will enhance the thermal conductivity. The Young’s modulus was found decreasing as the volume fraction of nickel increases, which would result in enhanced fracture toughness. Electrical conductivity was found to be greatly affected by the percolation phenomenon in the designed range of volume fraction minimum particle size. As a validation, Al2O3 composites with 10% and 15% volume fraction Ni and droplet size of 18 μm are developed using spark Plasma Sintering process. Thermal conductivity and thermal expansion coefficient of the samples are measured to complement the computational design. Microstructural analysis of the sintered samples was also studied using optical microscope to study the morphology of the developed samples. It was found that the present computational design tool was accurate enough in predicting the desired properties of Al2O3-Ni composites.

Influence of the Microstructure on the U1-yAmyO2-x (y= 0.1; 0.15) Pellet Macroscopic Swelling

2010 ◽  
Vol 73 ◽  
pp. 104-108 ◽  
Author(s):  
Damien Prieur ◽  
Aurélien Jankowiak ◽  
Caroline Leorier ◽  
Nathalie Herlet ◽  
Louis Donnet ◽  
...  
Keyword(s):  
Experimental Data ◽  
Powder Metallurgy ◽  
Room Temperature ◽  
Powder Metallurgy Process ◽  
Metallurgy Process ◽  
Α Particles

This work is devoted to the study of the geometrical stability in time of UyAm1-yO2-x pellet due to self-irradiation at room temperature. Dense and tailored porosity U1-yAmyO2-x (y=0.10; 0.15) compounds were fabricated by a powder metallurgy process. Up to 3.4.1017 α particles/g, an increase in the diameter of 0.9% was observed for the dense compounds while for the tailored porosity material a diameter increase of 0.4% was observed. Swelling laws have been established from the experimental data.

Powder Metallurgy

2013 ◽  
pp. 373-411
Keyword(s):  
Particle Size ◽  
Powder Metallurgy ◽  
Particle Shape ◽  
Dimensional Precision ◽  
Powder Blending ◽  
Powder Metallurgy Process ◽  
Powder Characteristics ◽  
Powder Manufacture ◽  
Secondary Operations ◽  
Metallurgy Process

Abstract This chapter covers the basic steps of the powder metallurgy process, including powder manufacture, powder blending, compacting, and sintering. It identifies important powder characteristics such as particle size, size distribution, particle shape, and purity. It compares and contrasts mechanical, chemical, electrochemical, and atomizing processes used in powder production, discusses powder treatments, and describes consolidation techniques along with secondary operations used to obtain special properties or improve dimensional precision. It also discusses common defects such as ejection cracks, density variations, and microlaminations.

A NOVEL DIELECTRIC CERAMIC FOR MICROWAVE PASSIVE CIRCUITS

2013 ◽  
Vol 22 ◽  
pp. 153-158 ◽  
Author(s):  
JOBIN VARGHESE ◽  
MATHEU PRESUME ◽  
KUZHICHALIL PEETHAMBHARAN SURENDRAN ◽  
MAILADIL THOMAS SEBASTIAN
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Room Temperature ◽  
Dielectric Ceramic ◽  
Microwave Frequencies ◽  
State Ceramic ◽  
Solid State Ceramic Route ◽  
Ceramic Route ◽  
First Time

The tetragonal Ca 9 Nd 2 W 4 O 24 (CNW) ceramic was prepared by the conventional solid state ceramic route and their dielectric properties were investigated in the radio and microwave frequencies. The CNW ceramics sintered at 1450 °C for 4 h showed a densification 92 % with εr = 16 and tanδ = 0.004 at 15.1 GHz. The thermal conductivity of ceramic at room temperature was found to be 1.6 W m−1K−1 and coefficent of thermal expansion of CNW ceramics was 4.2 ppm/°C measured in the range of 25 to 600 °C. The dielectric and thermal properties of CNW ceramic are reported for the first time.

Study on Electrical and Thermal Properties of Epoxy Resin/Inorganic Filler Composites for the Fully Enclosed Casting Bus Bar and its Calculation of the Temperature Field

2014 ◽  
Vol 804 ◽  
pp. 191-194 ◽  
Author(s):  
Nai Kui Gao ◽  
Yi Li Wang ◽  
Wen Xi Zhang ◽  
Zhao Liu ◽  
Chi Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Temperature Field ◽  
Thermal Properties ◽  
Epoxy Resin ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Room Temperature ◽  
Inorganic Filler ◽  
Study Results

This paper focused on the epoxy resin/inorganic filler composites. The electrical and thermal properties of the composites were tested and analyzed at room temperature. The influence of temperature on the thermal conductivity and thermal expansion coefficient was studied. Based on the electrical and thermal properties of the composites, the simulation model of the fully enclosed epoxy resin casting bus bar (FEERCB) was built, and the temperature field distribution of the FEERCB was calculated. T The study results showed that the volume resistivity, dielectric constant, dielectric loss factor and breakdown strength of the epoxy resin/inorganic filler composites were 1.74×1014Ω·cm, 3.44, 3.75 and 22.31 kV/mm respectively at room temperature. The thermal conductivity and thermal expansion coefficient of the composites were 2.55 W/m·K and 21.73×10-6 /°C, achieved the insulation requirements for FEERCB. In the temperature range of the test, with increasing temperature, the thermal conductivity reduced gradually, while the thermal expansion coefficient increased gradually. The simulation results showed that the FEERCB has remarkable performance on the heat dissipation and current carrying capability.

Sign in / Sign up

Export Citation Format

Share Document