scholarly journals Thermo-Mechanical Analysis of Aluminium Silicon Carbide Composite Materials

2020 ◽  
Vol 24 (6) ◽  
pp. 961-966
Author(s):  
M. Ekpu

In recent years, composite materials have dominated the electronics industries and other manufacturing industries. Hence, composite materials like aluminium silicon carbide (AlSiC), has been employed to produce heat sinks, which are used mainly to manage heat in electronic devices. However, thermal fatigue of such composite material is a major challenge in maintaining reliability of the device. This paper investigates the  thermomechanical effect of AlSiC composite materials. Finite element method (FEM) was used in the analyses of the composite materials based on the particulate inclusions between 10 – 50% compositions. The thermal profile (-40oC to 85oC) employed in this study is used commercially for consumer products. The fatigue life of the composite material which is based on the stresses and strains parameters were obtained and evaluated. The results from this investigation suggests that the deformations, strains, and stresses reduced with increase in the percentage of particulate inclusions. Also, the fatigue life of the composite material showed that the reliability of the material is increased with higher inclusions. This  investigation demonstrated that 50% particulate inclusions has a better number of cycles to fatigue failure (5.09E+04) when compare to other inclusions. While 10% inclusions has the least fatigue life (4.39E+04) based on this investigation. Keywords: composite material; temperature profile; silicon carbide; thermal fatigue

2021 ◽  
Vol 5 (3) ◽  
pp. 76
Author(s):  
Ho Sung Kim ◽  
Saijie Huang

S-N curve characterisation and prediction of remaining fatigue life are studied using polyethylene terephthalate glycol-modified (PETG). A new simple method for finding a data point at the lowest number of cycles for the Kim and Zhang S-N curve model is proposed to avoid the arbitrary choice of loading rate for tensile testing. It was demonstrated that the arbitrary choice of loading rate may likely lead to an erroneous characterisation for the prediction of the remaining fatigue life. The previously proposed theoretical method for predicting the remaining fatigue life of composite materials involving the damage function was verified at a stress ratio of 0.4 for the first time. Both high to low and low to high loadings were conducted for predicting the remaining fatigue lives and a good agreement between predictions and experimental results was found. Fatigue damage consisting of cracks and whitening is described.


Author(s):  
V. T. Senyut

The article presents the results of a study of composite materials based on diamond-lonsdaleite abrasive (DLA) and various binders (Fe–Ti mechanocomposite, silicon carbide SiC). A metal-matrix composite material with a multimodal nano- and microlevel structure, characterized by increased adhesion of diamond grains to the binder, is obtained on the basis of impact diamonds and a Fe–Ti nano-mechanical composite. It is shown that the use of impact diamonds in comparison with synthetic diamonds makes it possible to reduce the pressure of thermobaric treatment by 30–50 % at the same sintering temperatures. The use of Fe–Ti–DLA composites in the process of magnetic-abrasive polishing (MAP) makes it possible to increase the removal rate of material based on silicon by 1.5–2 times and reduce the processing time by 30 % compared to ferroabrasive powder (FAP) based on synthetic diamonds. The effect of adding of silicon carbide on the process of obtaining a superhard composite material impact diamond – SiC is investigated. It is found that adding of SiC helps to reduce the defectiveness of the material and increase the homogeneity of its structure in comparison with the material without adding of a binder. In this case, an increase in the content of SiC and Si also leads to an inversion of the structure type of the superhard composite from polycrystalline to matrix. It is found that the additional use of amorphous soot and boron affects the refinement of the matrix structure of the composite material due to the formation of boron carbide and secondary finely dispersed silicon carbide.


2020 ◽  
Vol 20 (10) ◽  
pp. 6482-6488
Author(s):  
Hansang Kwon ◽  
Mart Saarna ◽  
Marc Leparoux

Nano-silicon carbide (nSiC) particle-reinforced aluminium (Al) 6061 alloy matrix composites were fabricated by high-energy ball milling, hot-pressing (HP), and hot-forging (HF). The composite powders were degassed and the composites were synthesised under air and/or vacuum. Mechanical properties of the obtained composite materials were evaluated using various tests, including indentation, compression, four-point bending, and tensile tests as well as by microstructural observations. Different amounts of nSiC were added and the mechanical properties of the obtained composite materials were measured and discussed. The microstructures of the composites depended on the nSiC content and synthesis conditions. The Vickers hardness and tensile strength values of the nSiC reinforced Al 6061 composites were approximately three times higher than that of a pure Al 6061 alloy bulk. The results demonstrated that the small amount of nSiC particles functioned as efficient reinforcement material in the Al 6061 alloy matrix composite material and that the strength and ductility of the composite material can be controlled by adjusting the processing parameters and nSiC content.


Author(s):  
V.G. Babashov ◽  
◽  
N.M. Varrik ◽  
V.G. Maksimov ◽  
O.N. Samorodova ◽  
...  

The article presents the results of an experiment on the application of a silicon carbide coating on an alumina fiber and studies the properties of the resulting coated fibers. The purpose of applying a barrier coating to the fibers is to protect the fiber from degradation during the manufacturing of a ceramic composite material. The paper gives the characteristics of barrier coatings, such as thickness, continuity, structure, thermal and thermo-oxidative properties. The obtained data will be useful in the development of new types of ceramic composite materials reinforced with fibers.


2020 ◽  
pp. 75-86
Author(s):  
Sergio Antonio Camargo ◽  
Lauro Correa Romeiro ◽  
Carlos Alberto Mendes Moraes

The present article aimed to test changes in cooling water temperatures of males, present in aluminum injection molds, to reduce failures due to thermal fatigue. In order to carry out this work, cooling systems were studied, including their geometries, thermal gradients and the expected theoretical durability in relation to fatigue failure. The cooling system tests were developed with the aid of simulations in the ANSYS software and with fatigue calculations, using the method of Goodman. The study of the cooling system included its geometries, flow and temperature of this fluid. The results pointed to a significant increase in fatigue life of the mold component for the thermal conditions that were proposed, with a significant increase in the number of cycles, to happen failures due to thermal fatigue.


2020 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Atyaksheva ◽  
Yermek Sarsikeyev ◽  
Anastasia Atyaksheva ◽  
Olga Galtseva ◽  
Alexander Rogachev

Aims:: The main goals of this research are exploration of energy-efficient building materials when replacing natural materials with industrial waste and development of the theory and practice of obtaining light and ultra-light gravel materials based on mineral binders and waste dump ash and slag mixtures of hydraulic removal. Background.: Experimental data on the conditions of formation of gravel materials containing hollow aluminum and silica microsphere with opportunity of receipt of optimum structure and properties depending on humidity with the using of various binders are presented in this article. This article dwells on the scientific study of opportunity physical-mechanical properties of composite materials optimization are considered. Objective.: Composite material contains hollow aluminum and silica microsphere. Method.: The study is based on the application of the method of separation of power and heat engineering functions. The method is based on the use of the factor structure optimality, which takes into account the primary and secondary stress fields of the structural gravel material. This indicates the possibility of obtaining gravel material with the most uniform distribution of nano - and microparticles in the gravel material and the formation of stable matrices with minimization of stress concentrations. Experiments show that the thickness of the cement shell, which performs power functions, is directly related to the size of the raw granules. At the same time, the thickness of the cement crust, regardless of the type of binder, with increasing moisture content has a higher rate of formation for granules of larger diameter. Results.: The conditions for the formation of gravel composite materials containing a hollow aluminosilicate microsphere are studied. The optimal structure and properties of the gravel composite material were obtained. The dependence of the strength function on humidity and the type of binder has been investigated. The optimal size and shape of binary form of gravel material containing a hollow aluminosilicate microsphere with a minimum thickness of a cement shell and a maximum strength function was obtained. Conclusion.: Received structure allows to separate power and heat engineering functions in material and to minimize the content of the excited environment centers.


Author(s):  
Theddeus Tochukwu Akano

Normal oral food ingestion processes such as mastication would not have been possible without the teeth. The human teeth are subjected to many cyclic loadings per day. This, in turn, exerts forces on the teeth just like an engineering material undergoing the same cyclic loading. Over a period, there will be the creation of microcracks on the teeth that might not be visible ab initio. The constant formation of these microcracks weakens the teeth structure and foundation that result in its fracture. Therefore, the need to predict the fatigue life for human teeth is essential. In this paper, a continuum damage mechanics (CDM) based model is employed to evaluate the fatigue life of the human teeth. The material characteristic of the teeth is captured within the framework of the elastoplastic model. By applying the damage evolution equivalence, a mathematical formula is developed that describes the fatigue life in terms of the stress amplitude. Existing experimental data served as a guide as to the completeness of the proposed model. Results as a function of age and tubule orientation are presented. The outcomes produced by the current study have substantial agreement with the experimental results when plotted on the same axes. There is a notable difference in the number of cycles to failure as the tubule orientation increases. It is also revealed that the developed model could forecast for any tubule orientation and be adopted for both young and old teeth.


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