Investigation of the effect of B4C amount and sintering temperature on the thermal properties of the material in Al 1070–B4C composites

2021 ◽  
pp. 146442072110355
Author(s):  
Zühtü Onur Pehlivanlı ◽  
Muharrem Pul
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Composite Materials ◽  
Composite Structure ◽  
Sintering Temperature ◽  
Reinforcement Ratio ◽  
Heat Conduction Coefficient ◽  
Ambient Temperatures

Today, the usage area of metal matrix and ceramic reinforced composites is increasing and researches in this field are increasing. However, majority of the studies conducted are constituted of studies on investigation of mechanical features of composites. One of the reasons why composite materials are preferred is because these materials have improved thermal property. With this experimental study, it is aimed to contribute to the literature in the area of investigating features of thermal properties. In this study, composite materials were produced at 500 °C, 550 °C and 600 °C sintering temperatures by adding 4%, 8% and 16% B4C to Al 1070 quality aluminium by powder metallurgy technique. Firstly, the microstructures of the composites were investigated. Then, experiments were conducted to determine the specific heat of composite materials at different ambient temperatures together with thermal conductivity measurements. With the data obtained from the experiments, finite-element modelling was done and the thermal properties of the composite structure were optimised. In the microstructure studies, it was determined that with the increase in the B4C reinforcement ratio, the reinforcement agglomeration and porosity in the composite structure were found. As a result of the thermal experiments, it was observed that the thermal conductivity values of the composites were inversely proportional to the amount of B4C reinforcement and as the reinforcement ratio increased, the thermal conductivity values decreased. Besides, it was determined that the sintering temperature has an effect on the thermal conductivity value and that it increases the thermal conductivity of the composites with increasing sintering temperature. The highest heat conduction coefficient was obtained at 4% B4C reinforcement ratio and 600 °C sintering temperature. It was observed that the finite-element models prepared to determine the heat conduction coefficient effectively were consistent with the experimental results.

scholarly journals Research on the Compound Optimization Method of the Electrical and Thermal Properties of SiC/EP Composite Insulating Material

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3369
Author(s):  
Xupeng Song ◽  
Xiaofeng Xue ◽  
Wen Qi ◽  
Jin Zhang ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Composite Materials ◽  
Breakdown Strength ◽  
Optimization Method ◽  
Nano Particles ◽  
Electrical Performance ◽  
Conduction Channel

In this paper, in order to improve the electrical and thermal properties of SiC/EP composites, the methods of compounding different crystalline SiC and micro-nano SiC particles are used to optimize them. Under different compound ratios, the thermal conductivity and breakdown voltage parameters of the composite material were investigated. It was found that for the SiC/EP composite materials of different crystal types of SiC, when the ratio of α and β silicon carbide is 1:1, the electrical performance of the composite material is the best, and the breakdown strength can be increased by more than 10% compared with the composite material filled with single crystal particles. For micro-nano compound SiC/EP composites, different total filling amounts of SiC correspond to different optimal ratios of micro/nano particles. At the optimal ratio, the introduction of nanoparticles can increase the breakdown strength of the composite material by more than 10%. Compared with the compound of different crystalline SiC, the advantage is that the introduction of a small amount of nanoparticles can play a strong role in enhancing the break-down field strength. For the filled composite materials, the thermal conductivity mainly depends on whether an effective heat conduction channel can be constructed. Through experiments and finite element simulation calculations, it is found that the filler shape and particle size have a greater impact on the thermal conductivity of the composite material, when the filler shape is rounder, the composite material can more effectively construct the heat conduction channel.

The Study of Thermal Properties and Micro Structures of YSZ

2007 ◽  
Author(s):  
S. M. Guo ◽  
M. B. Silva ◽  
Patrick F. Mensah ◽  
Nalini Uppu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Gas Turbine ◽  
Bond Coat ◽  
Sintering Temperature ◽  
Heating Process ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Low Thermal Conductivity ◽  
Gas Tight

Thermal barrier coatings (TBCs) are used in gas turbine engines to achieve a better efficiency by allowing increased turbine inlet temperature and decreasing the amount of cooling air used. Plasma spraying is one of the most reliable methods to produce TBCs, which are generally comprised of a top coating of ceramic and a bond-coat of metal. Usually, the top coating is Yttria-Stabilized-Zirconia (YSZ), providing the thermal barrier effect. The bond-coat is typically a layer of M-Cr-Al-Y (where “M” stands for “metal”), employed to improve the attachment between the ceramic top-coat and the substrate. Due to the extreme temperature gradient presented in the plasma jet and the wide particle size distribution, during the coating process, injected ceramic powders may experience a significantly different heating process. Different heating history, coupled with the substrate preheating temperature, may affect the thermal properties of the YSZ layers. In this paper, four sets of mol 8% YSZ disks are fabricated under controlled temperatures of 1100°C, 1200°C, 1400°C and 1600°C. Subsequently the thermal properties and the microstructures of these YSZ disks are studied. The results indicate a strong microstructure change at a temperature slightly below 1400°C. For a high sintering temperature, a dense YSZ layer can be formed, which is good for gas tight operation; At low sintering temperature, say 1200°C, a porous YSZ layer is formed, which has the advantage of low thermal conductivity. For gas turbine TBC applications, a robust low thermal conductivity YSZ layer is desirable, while for Solid Oxide Fuel Cells, a gas-tight YSZ film must be formed. This study offers a general guideline on how to prepare YSZ layers, mainly by controlling the heating process, to form microstructures with desired properties.

Influence of Palm Oil Fibers Length Variation on Mechanical Properties of Reinforced Crude Bricks

2022 ◽  
Author(s):  
Mazhar Hussain ◽  
Daniel Levacher ◽  
Nathalie Leblanc ◽  
Hafida Zmamou ◽  
Irini Djeran Maigre ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Composite Materials ◽  
Physical Properties ◽  
Palm Oil ◽  
Mechanical Characteristics ◽  
Natural Fibers ◽  
Indirect Tensile

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percentage of fibers, length of fibers and distribution of fibers inside the bricks have significant effect on mechanical, physical and thermal properties of biobased composite materials. It can be observed by tests such as indirect tensile strength, compressive strength for mechanical characteristics, density, shrinkage, color for physical properties, thermal conductivity and resistivity for thermal properties, and inundation test for durability of crude bricks. In this study, mechanical and physical characteristics of crude bricks reinforced with palm oil fibers are investigated and effect of change in percentage and length of fibers is observed. Crude bricks of size 4*4*16 cm3 are manufactured with dredged sediments from Usumacinta River, Mexico and reinforced with palm oil fibers at laboratory scale. For this purpose, sediments and palm oil fibers characteristics were studied. Length of fibers used is 2cm and 3cm. Bricks manufacturing steps such as sediments fibers mixing, moulding, compaction and drying are elaborated. Dynamic compaction is opted for compaction of crude bricks due to energy control. Indirect tensile strength and compressive strength tests are conducted to identify the mechanical characteristics of crude bricks. Physical properties of bricks are studied through density and shrinkage. Durability of crude bricks is observed with inundation test. Thermal properties are studied with thermal conductivity and resistivity test. Distribution and orientation of fibers and fibers counting are done to observe the homogeneity of fibers inside the crude bricks. Finally, comparison between the mechanical characteristics of crude bricks manufactured with 2cm and 3cm length with control specimen was made.

scholarly journals Effect of Fiber Geometry and Representative Volume Element on Elastic and Thermal Properties of Unidirectional Fiber-Reinforced Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Siva Bhaskara Rao Devireddy ◽  
Sandhyarani Biswas
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Thermal Properties ◽  
Elastic Modulus ◽  
Cross Section ◽  
Representative Volume Element ◽  
Material Properties ◽  
Volume Element ◽  
Unidirectional Fiber ◽  
Representative Volume

The aim of present work is focused on the evaluation of elastic and thermal properties of unidirectional fiber-reinforced polymer composites with different volume fractions of fiber up to 0.7 using micromechanical approach. Two ways for calculating the material properties, that is, analytical and numerical approaches, were presented. In numerical approach, finite element analysis was used to evaluate the elastic modulus and thermal conductivity of composite from the constituent material properties. The finite element model based on three-dimensional micromechanical representative volume element (RVE) with a square and hexagonal packing geometry was implemented by using finite element code ANSYS. Circular cross section of fiber and square cross section of fiber were considered to develop RVE. The periodic boundary conditions are applied to the RVE to calculate elastic modulus of composite. The steady state heat transfer simulations were performed in thermal analysis to calculate thermal conductivity of composite. In analytical approach, the elastic modulus is calculated by rule of mixture, Halpin-Tsai model, and periodic microstructure. Thermal conductivity is calculated analytically by using rule of mixture, the Chawla model, and the Hashin model. The material properties obtained using finite element techniques were compared with different analytical methods and good agreement was achieved. The results are affected by a number of parameters such as volume fraction of the fibers, geometry of fiber, and RVE.

Algebraically Explicit Analytical Solutions of Unsteady Conduction With Variable Thermal Properties in Spheroidal Coordinates

2004 ◽  
Author(s):  
Ruixian Cai ◽  
Na Zhang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Analytical Solutions ◽  
Numerical Solutions ◽  
Spherical Coordinates ◽  
Rectangular Coordinates ◽  
Conduction Theory ◽  
Unsteady Heat Conduction ◽  
Spheroidal Coordinates

The analytical solutions of unsteady heat conduction with variable thermal properties (thermal conductivity, density and specific heat are functions of temperature or coordinates) are meaningful in theory. In addition, they are very useful to the computational heat conduction to check the numerical solutions and to develop numerical schemes, grid generation methods and so forth. Such solutions in rectangular coordinates have been derived by the authors; some other solutions for unsteady point symmetrical heat conduction in spherical coordinates are given in this paper to promote the heat conduction theory and to develop the relative computational heat conduction.

Modeling Heat Conduction Across Thermal Interface Materials With Micro-Particles

2008 ◽  
Author(s):  
C. Channy Wong
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Composite Materials ◽  
Effective Thermal Conductivity ◽  
Thermal Interface Materials ◽  
Conduction Path ◽  
Micro Particles ◽  
Mechanical And Electrical Properties ◽  
Interface Materials ◽  
Composite Polymeric Material

Different types of fillers with high electrical and thermal conductivities, e.g. graphite and alumina, have been added to adhesive polymers to create composite materials with improved mechanical and electrical properties. Previous modeling efforts have found that it is relatively difficult to predict the effective thermal conductivity of a composite polymeric material when incorporated with large volume content of fillers. We have performed comprehensive computational analysis that models the thermal contacts between fillers. This unique setup can capture the critical heat conduction path to obtain the effective thermal conductivity of the composite materials. Results of these predictions and its comparison with experimental data will be presented in this paper.

scholarly journals Experimental investigations into mechanical and thermal properties of rapid manufactured copper parts

2019 ◽  
Vol 234 (1) ◽  
pp. 82-95 ◽  
Author(s):  
Gurminder Singh ◽  
Pulak M Pandey
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Ultimate Tensile Strength ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Mechanical And Thermal Properties ◽  
Surface Porosity ◽  
Soaking Time ◽  
Ultrasonic Assisted

In the present paper, mechanical and thermal properties of rapidly manufactured copper parts were studied. The combination of three-dimensional printing and ultrasonic assisted pressureless sintering was used to fabricate copper parts. First, the ultimate tensile strength and thermal conductivity were compared between ultrasonic assisted and conventional pressureless sintered samples. The homogenously mixing of particles and local heat generation by ultrasonic vibrations promoted the sintering driving process and resulted in better mechanical and thermal properties. Furthermore, response surface methodology was adopted for the comprehensive study of the ultrasonic sintering parameters (sintering temperature, heating rate, and soaking time with ultrasonic vibrations) on ultimate tensile strength and thermal conductivity of the fabricated sample. Analysis of variance was performed to identify the significant factors and interactions. The image processing method was used to identify the surface porosity at different parameter levels to analyse the experimental results. High ultimate tensile strength was obtained at high sintering temperature, long soaking time, and slow heating rate with low surface porosity. After 60 min of soaking time, no significant effect was observed on the thermal conductivity of the fabricated sample. The significant interactions revealed less effect of soaking time at low sintering temperatures for ultimate tensile strength and less effect of heating rate at low sintering temperatures for thermal conductivity. Multi-objective optimization was carried out to identify parameters for maximum ultimate tensile strength and maximum thermal conductivity.

The Effect of Sintering Temperature to the Properties of Zinc Oxide

2013 ◽  
Vol 795 ◽  
pp. 419-423 ◽  
Author(s):  
J.H. Lim ◽  
C.K. Yeoh ◽  
Pei Leng Teh ◽  
W.M. Arif ◽  
A. Chik
Keyword(s):  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Thermal Properties ◽  
Solid State ◽  
Sintering Temperature ◽  
Solid State Method ◽  
Influence Of Temperature ◽  
Temperature Range ◽  
Influence Of Temperature On ◽  
State Method

In this paper, different sintering temperature used to study the influence of temperature on the structural and thermal properties of zinc oxide (ZnO). On this research, the sample was prepared by solid-state method for zinc oxide (ZnO) at different sintering temperature which was 700°C, 800°C and 900°C. It was observed that the density of bulk ZnO that sintering at 900°C had the higher value of density 5.03 g/cm3. The microhardness of the bulk ZnO had a higher measurement 397.3 Hv after sintered at 900°C. ZnO that sintering at 900°C had been observed that had thermal conductivity 1.1611W/cm-K in the sintering temperature range 700°C to 900°C.

Thermal Aspects of Grinding: The Effect of the Wheel Bond on Heat Transfer to an Abrasive Grain

1991 ◽  
Vol 113 (4) ◽  
pp. 395-401 ◽  
Author(s):  
M. W. Harris ◽  
A. S. Lavine
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Beneficial Effect ◽  
Surface Temperature ◽  
Thermal Damage ◽  
High Thermal Conductivity ◽  
Abrasive Grain ◽  
Grain Surface

Heat generated during grinding can cause thermal damage to the workpiece and wheel. It is therefore important to understand the thermal aspects of grinding. This paper addresses heat conduction into the wheel, by considering a single abrasive grain in contact with the workpiece. In particular, the effect of the bond material on conduction into the grain is investigated. The results for the grain surface temperature are given in terms of parameters describing the geometry and thermal properties of the grain and bond. The beneficial effect of a high thermal conductivity for both the grain and the bond is clearly demonstrated.

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