scholarly journals The influence of microstructure on mechanical properties of 3D printable geopolymer composites

2020 ◽  
Vol 322 ◽  
pp. 01011
Author(s):  
Kinga Korniejenko ◽  
Krzysztof Miernik ◽  
Wei-Ting Lin ◽  
Arnaud Castel

The additive manufacturing technologies are fast-developing industrial sector and, potentially, a ground-breaking technology. They have many advantages such as the saving of resources and energy efficiency. However, the full exploitation of 3D printing technology for ceramic materials is currently limited; a lot of research is being conducted in this area. A promising solution seems to be geopolymers, but its application requires a better understanding of the behaviour this group of materials. This article analyses the influence of microstructure on mechanical properties whilst taking the production method into consideration. The paper is based on comparative analysis – the investigation is focused on the influence of material structure on the mechanical properties and fracture mechanism of these kinds of composites, including those reinforced with different kind of fibres. As a raw material for the matrix, fly ash from the Skawina coal power plant (located in: Skawina, Lesser Poland, Poland) was used. The investigation was made by SEM analysis. The results show that the microstructural analysis did not sufficiently explain the underlying reasons for the observed differences in the mechanical properties of the composites.

2018 ◽  
Vol 225 ◽  
pp. 03007
Author(s):  
Balaji Bakthavatchalam ◽  
Khairul Habib ◽  
Namdev Patil ◽  
Omar A Hussein

Microstructural Analysis plays an important role in enhancing the mechanical properties of metals and composites. Usually Aluminium Silicon Carbide (Al6063/SiC) alloys are mixed with strontium, sodium and antimony for high durability even though they are toxic and costly. As an alternative calcium is used as an alloying element to improve the mechanical property of Al6063/Sic alloy. In this paper Al6063 is chosen as the matrix material while Sic is used as a reinforcement where calcium powder is added to modify the silicon phase of the composite. Finally, concentration of Silicon carbide is varied from 0 to 150 mg to produce four specimens of Al6063 alloy and it is subjected to microstructure analysis which showed the reduction of grain size and therefore improvement in the hardness from 52.9 HV to 58.4 HV and decrease in the wear loss from 3.97 to 3.27 percentage.


Author(s):  
Marius C. Barbu ◽  
Roman Reh ◽  
Ayfer Dönmez Çavdar

It would seem that with appropriate treatment almost any agricultural residue may be used as a suitable raw material for the wood-based panels like particle- and fiberboard production. The literature on wood-ligno-cellulose plant composite boards highlights steady interest for the design of new structures and technologies towards products for special applications with higher physical-mechanical properties at relatively low prices. Experimental studies have revealed particular aspects related to the structural composition of ligno-cellulose materials, such as the ratio between the different composing elements, their compatibility, and the types and characteristics of the used resins. Various technologies have been developed for designing and processing composite materials by pressing, extrusion, airflow forming, dry, half-dry, and wet processes, including thermal, chemical, thermo-chemical, thermo-chemo-mechanical treatments, etc. Researchers have undertaken to determine the manufacturing parameters and the physical-mechanical properties of the composite boards and to compare them with the standard PB, MDF, HB, SB made from single-raw material (wood). A great emphasis is placed on the processability of the ligno-cellulose composite boards by classical methods, by modified manufacturing processes, on the types of tools and processing equipment, the automation of the manufacturing technologies, the specific labor conditions, etc. The combinations of wood and plant fibers are successful, since there is obvious compatibility between the macro- and microscopic structures, their chemical composition, and the relatively low manufacturing costs and high performances, as compared to synthetic fiber-based composite materials.


2011 ◽  
Vol 383-390 ◽  
pp. 3366-3373
Author(s):  
Shuo Qin ◽  
Bo Lin Wu ◽  
Shiao Zhao ◽  
Cong Chang Ma ◽  
Zu Sheng Hu

Red mud is the main solid residue generated during the production of alumina by means of the Bayer process. In order to expand the comprehensive utilization field of red mud and develop new ceramic products with low radioactivity utilizing red mud, the exploration of preparing self-releasing glaze ceramic materials using red mud as raw material was carried out. During the exploration, the self-releasing glaze ceramic materials with low radiation level were produced by normal pressure sintering process using the main ingredients of red mud, red sandstone, barium carbonate and ball clay. The properties of the self-releasing glaze ceramic samples were investigated by the measurements of mechanical properties, X-ray diffraction (XRD), scanning electron microscopy (SEM) and radiation measurement. The results show that the self-releasing glaze ceramic materials have good mechanical properties (the bulk density, 3.10 g/cm3; the compressive strength, 78.00 MPa). Adding barium carbonate to the raw materials and then calcine them to ceramics, which can extend the sintering temperature range and the radioactivity level of the self-releasing glaze ceramic materials can be reduced to that of the natural radioactive background of Guilin Area, Karst landform (the average 60 Total/Timer).


1992 ◽  
Vol 287 ◽  
Author(s):  
M.J. Hoffmann ◽  
G. Petzow

ABSTRACTParameters controlling the size and aspect ratio of elongated Si3N4 grains are discussed, based on the assumption that only pre-existing β-Si3N4 particles of the starting powder grow. Powder mixtures of α-rich and β-rich Si3N4 were prepared In order to study the microstructural development. The resulting microstructures were analyzed by quantitative microstructural analysis determining the distribution of the length and aspect ratio of the Si3N4 grains. Subsequently, the Influence of the sintering conditions on grain growth was analyzed In relation to mechanical properties. A high Weibull modulus and the non-catastrophic failure during thermal shock of coarse-grained materials Is attributed to an R-curve behaviour. Finally, the influence of sintering additives on the mechanical properties was studied. The Importance of phase relationships between the matrix and the grain boundary phase Is discussed for Si3N4 with Yb2O3 additives. It Is demonstrated that the oxygen content of Si3N4 powder must been taken Into account In order to devitrify defined secondary phases and to achieve a high degree of crystallization. A reduction in the amount of additives does not necessarily Improve the properties as high temperature strength and creep data Indicate.


Author(s):  
Dumitru Nedelcu ◽  
Constantin Carausu ◽  
Ciprian Ciofu

The use of recyclable materials has become an important trend in all activity areas, reason why material based on liquid wood called Arbofill, Arboblend and Arboform will replace plastic in different applications in the near future. The new materials are the main substances that have an important effect on company development and require some simple or complex manufacturing technologies. In case of Arboform L, V3 Nature the injected parts can be obtained using the same injection machines used for the injection of plastic materials. The technological injection parameters, such as: injection pressure, injection time, cooling time, mold temperature, etc., are different. The experimental research focused on tensile strength, friction coefficients, SEM analysis, XRD analysis and EDAX analysis. Considering all of these experimental results the Arboform L, V3 Nature reinforced with aramid fibers could replace the following plastic materials PA12, PVDF, ECTFE, PA66, PA12, PC, PP, PP GF 30, etc. Also taking into account all the results obtained, this material can replace plastic materials in many applications, such as: ornaments, including for cars, connectors, switches etc., electrical industry, different mobile accessories, computers, televisions, mobile phone cases, etc. The material obtained from Arboform reinforced with aramid fibers (5% percent) improved the injection process despite of easy decreasing of mechanical properties.


Author(s):  
P. Angelini ◽  
W. Mader

Whisker reinforced ceramic materials offer the potential for increased fracture toughness and fracture strength. Residual stresses resulting from differences in thermal expansion properties of the matrix and the whisker can develop during cooling and affect mechanical properties. TEH strain contrast of large inclusions has previously been observed for nearly spherical particles of ZrO2 in Al2O3 matrix grains. The formation of strain contrast oscillations was explained and a quantitative analysis of strains around ZrO2 inclusions in Al2O3 was performed. The present research is concerned with characterizing by TEM the strain field present in Al2O3 reinforced with SiC whiskers.


Author(s):  
Marius C. Barbu ◽  
Roman Reh ◽  
Ayfer Dönmez Çavdar

It would seem that with appropriate treatment almost any agricultural residue may be used as a suitable raw material for the wood-based panels like particle- and fiberboard production. The literature on wood-ligno-cellulose plant composite boards highlights steady interest for the design of new structures and technologies towards products for special applications with higher physical-mechanical properties at relatively low prices. Experimental studies have revealed particular aspects related to the structural composition of ligno-cellulose materials, such as the ratio between the different composing elements, their compatibility, and the types and characteristics of the used resins. Various technologies have been developed for designing and processing composite materials by pressing, extrusion, airflow forming, dry, half-dry, and wet processes, including thermal, chemical, thermo-chemical, thermo-chemo-mechanical treatments, etc. Researchers have undertaken to determine the manufacturing parameters and the physical-mechanical properties of the composite boards and to compare them with the standard PB, MDF, HB, SB made from single-raw material (wood). A great emphasis is placed on the processability of the ligno-cellulose composite boards by classical methods, by modified manufacturing processes, on the types of tools and processing equipment, the automation of the manufacturing technologies, the specific labor conditions, etc. The combinations of wood and plant fibers are successful, since there is obvious compatibility between the macro- and microscopic structures, their chemical composition, and the relatively low manufacturing costs and high performances, as compared to synthetic fiber-based composite materials.


2015 ◽  
Vol 663 ◽  
pp. 34-41 ◽  
Author(s):  
Fernanda Andreola ◽  
Isabella Lancellotti ◽  
Rosa Taurino ◽  
Cristina Leonelli ◽  
Luisa Barbieri

Virgin raw materials can be partially replaced by glass waste in order to reduce the environmental impact being its recycling a significant problem for municipalities worldwide. In Italy in 2013, approximately 1,600,000 tons of container glass have been collected but it was not possible to recycle all of them in the glass melting process.This work is focused on the valorization of glass waste as raw material in new cement and ceramic products, to convert it from an environmental and economic burden to a profitable, added-value resource in the formulation of new mixes. Several parameters, such as grinding, forming, firing, etc. have been studied.It has been optimized the grinding and the reclaiming step of waste to obtain an alternative raw material for hot and cold consolidation processes. Chemical, physical and mechanical properties of products were carried out. The results show new real possibilities to use high amounts of glass waste as an alternative raw material in products consolidated either by hot or cold techniques, reducing the management problems of the glass waste.


Author(s):  
Kinga Korniejenko ◽  
Gábor Mucsi ◽  
Nóra Papné Halyag ◽  
Roland Szabó ◽  
Dariusz Mierzwiński ◽  
...  

This article analyses the influence of a short basalt fibre admixture on the mechanical properties of geopolymers, especially compressive strength. This preliminary research is the first step towards the development of a composite for fire resistant applications in civil engineering. This study investigates the behaviour of a fly ash based geopolymer containing basalt fibres. Fly ash from the coal power plant ‘Skawina’ (located in: Skawina, Lesser Poland, Poland) was used as the raw material. The chemical composition of this fly ash is typical for class F. Three series of fly ash based geopolymers were cast. In the first, short basalt fibres were added as 1% by weight of fly ash, in the second short basalt fibres were added as 2% by weight of fly ash and the third functioned as a control series without any fibres. Each series of samples were tested on compressive strength after 28, 14 and 7 days, and specimen density was determined. Additionally, microstructural analysis was carried out after 28 days. The results show that the addition of basalt fibres can improve the mechanical properties of geopolymer composites. Keywords: geopolymer, basalt fibre, composites, fire resistance


2021 ◽  
Vol 31 (1) ◽  
pp. 51-56
Author(s):  
Ashish Kumar Srivastava ◽  
Ambuj Saxena ◽  
Nagendra Kumar Maurya ◽  
Shashi Prakash Dwivedi

In the current scenario, the development of high strength and low weight material is the demand of the aerospace defence organizations. Magnesium alloy based composite has low density, good mechanical and physical properties. In this study, magnesium alloy AZ31B is used as reinforcement material and graphene nanoparticle is used as reinforcement material. Stir casting technique is used for the development of composite material. Three weight percentages i.e. 0.4%, 0.8% and 1.2% are used for the casting. The microstructural analysis is performed to validate the presence of graphene particles in the developed composite. Further mechanical properties such as tensile strength, hardness and toughness are evaluated. Experimental results confirm that GNPs particles are uniformly distributed into the matrix material. It was observed that due to the reinforcement of GNPs particles tensile strength of the material is improved by 31.17%, hardness is improved about 46.9%. However, the peak value of toughness is observed 12.6 Jule/cm2 in the matrix material, it decreases by increasing the wt% of reinforcement particle and lowest value of toughness of 6.82 Jule/cm2 is observed in AZ31B/1.2%GNP composite.


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