A Comparison of Mechanical Properties of Different Hydroxyapatite (HAp) Based Nanocomposites: The Influence of Morphology and Preferential Orientation

2020 ◽  
Vol 20 (3) ◽  
pp. 1968-1976
Author(s):  
J. R. Alanís-Gómez ◽  
E. M. Rivera-Muñoz ◽  
C. Peza-Ledesma ◽  
A. Manzano-Ramírez ◽  
R. Velázquez-Castillo

Three different types of hydroxyapatite (HAp) based porous ceramic materials were obtained through the modified gel casting method; one of them was made of commercial HAp particles and used as a reference in the mechanical characterization. Other type of ceramic was elaborated using HAp nanofibers, which were synthesized through the microwave assisted hydrothermal method and they possess a high crystallinity, purity and a preferential crystalline orientation in the [300], such were grown along the [001]. The third type of porous ceramic was elaborated using a combination of HAp nanofibers and particles. The HAp nanofibers and particles were previously analyzed by using X-ray diffraction to study their crystal structure, the topology and morphology of those HAp aggregates were observed with scanning electron microscopy (SEM); high-resolution transmission electron microscopy was useful to carry out a detailed crystallographic analysis. Afterwards, an organic phase made of gelatin was added to the porous ceramics in order to obtain nanocomposite materials. Two different concentrations of gelatin were used separately, and the combination of three types of porous ceramics and two concentrations of gelatin produced six different nanocomposite materials. All of these composite materials were observed through the SEM to see their topology and porosity and after that, they were probed under compression tests and their corresponding mechanical behavior was analyzed. All the composites showed mechanical properties similar to those observed in cellular materials. The Young modulus and ultimate strength were compared, finally, it was determined the contribution to the mechanical properties of the morphology, crystalline quality and preferential crystalline orientation in the HAp nanofibers. According to such properties, the composite material made of HAp nanofibers has bone tissue implant potential applications.

2014 ◽  
Vol 925 ◽  
pp. 464-468 ◽  
Author(s):  
Aleksandrs Korjakins ◽  
Liga Upeniece ◽  
Diana Bajare

Anxiety of society about global warming is increasingly growing and interest about construction materials that are less harmful to the environment is growing as well. Manufactures and scientists are urged to think about the usage of more effective resources, which are available and necessary for production, as well as to find possibilities and solutions for the decrease of primary energy resource depletion by producing ecological materials. Clay is one of local raw materials that can help solving growing problems by production of ceramic materials and their products, as well as more widely distributed sediments, which mainly form the upper part of Earth’s crust. Alongside traditional ceramic materials, porous ceramics are also widely researched, becoming an increasingly popular material in the world, mainly owing to their wide possibilities of usage in different technical and technology industries – from construction to mechanical engineering, health industry and even space technology. Obtaining porous ceramics using different kind of burnable fillers, such as natural products obtained as waste from agricultural industry, as well as controllable form products obtained from polymers, allow to form desirable porous structures within wide ranges: with pore dimensions starting from some micrometers up to 2-3 millimeters. Porous ceramic materials obtained within this research are breathing, they are thermostable materials, resistant to thermal impacts, corrosion and are easy in processing. During the presented research porous ceramics were produced using different kinds of burnable fillers. The optimal burning treatment was developed for obtaining required mechanical properties of porous ceramics. The physical-mechanical properties of obtained ceramics were evaluated.


2020 ◽  
Vol 67 (1) ◽  
pp. 148-155
Author(s):  
Anatoliy V. Fedotov ◽  
Viktor S. Grigoriev ◽  
Dmitriy A. Kovalev ◽  
Andrey A. Kovalev

To speed up the wastewater treatment under aerobic conditions and to optimize the processes of anaerobic wastewater treatment in digesters, immobilization technologies of microorganisms and enzymes on solid carriers are used. Ceramic carriers based on aluminosilicates and alumina are one of the promising inorganic biomass carriers. (Research purpose) To study the structure of porous ceramic biomass carriers for anaerobic processing of organic waste and evaluate the prospects for their use. (Materials and methods) The substrate for anaerobic digestion was a mixture of sediments of the primary and secondary sewage sumps of the Lyubertsy treatment facilities. K-65 cattle feed was used to ensure the constancy of the composition of organic substances in substrates as a cosubstrate. The authors used the method of low-temperature nitrogen adsorption of Bruner-Emmett-Teller to study the pore structure and specific surface of solid carriers on a specific surface analyzer Quntachrome Autosorb-1. (Results and discussion) The main characteristics (specific surface, volume of micro- and mesopores, predominant pore radius, water absorption and others) of chamotte foam lightweight and highly porous corundum ceramics were determined. It was revealed that ceramic materials with a developed surface and electrically conductive material provided an increase in biogas yield by 3.8-3.9 percent with an increase in methane content by an average of 5 percent. (Conclusions) The results of anaerobic digestion showed a positive effect of both a conductive carrier and highly porous ceramic materials on the process of anaerobic bioconversion of organic waste into biogas. It is advisable to expand experimental studies on the use of a conductive carrier with a developed surface based on highly porous ceramics.


2021 ◽  
Vol 11 (13) ◽  
pp. 6056
Author(s):  
Egle Rosson ◽  
Acacio Rincón Rincón Romero ◽  
Denis Badocco ◽  
Federico Zorzi ◽  
Paolo Sgarbossa ◽  
...  

Spent fluorescent lamps (SFL) are classified as hazardous materials in the European Waste Catalogue, which includes residues from various hi-tech devices. The most common end-of-life treatment of SFL consists in the recovery of rare earth elements from the phosphor powders, with associated problems in the management of the glass residues, which are usually landfilled. This study involves the manufacturing of porous ceramics from both the coarse glass-rich fraction and the phosphor-enriched fraction of spent fluorescent lamps. These porous materials, realizing the immobilization of Rare Earth Elements (REEs) within a glass matrix, are suggested for application in buildings as thermal and acoustic insulators. The proposed process is characterized by: (i) alkaline activation (2.5 M or 1 M NaOH aqueous solution); (ii) pre-curing at 75 °C; (iii) the addition of a surfactant (Triton X-100) for foaming at high-speed stirring; (iv) curing at 45 °C; (v) viscous flow sintering at 700 °C. All the final porous ceramics present a limited metal leaching and, in particular, the coarse glass fraction activated with 2.5 M NaOH solution leads to materials comparable to commercial glass foams in terms of mechanical properties.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3467
Author(s):  
Anna Nocivin ◽  
Doina Raducanu ◽  
Bogdan Vasile ◽  
Corneliu Trisca-Rusu ◽  
Elisabeta Mirela Cojocaru ◽  
...  

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti–Nb–Zr–Fe–O alloy of β-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of etot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young’s modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young’s modulus of about 48–49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of β-stabilizing alloying elements, especially the Zr/Nb ratio.


2015 ◽  
Vol 662 ◽  
pp. 237-240 ◽  
Author(s):  
Krzysztof Naplocha ◽  
Jacek W. Kaczmar ◽  
Jerzy Morgiel

The applied squeeze casting technique makes possible the local strengthening with ceramic fibers or ceramic particles of elements with Al-alloy matrices. In this paper the elaborated technology of manufacturing of porous ceramic preforms from Saffil fibers is shown and technology of squeeze casting elaborated at Wrocław University of Technology, Chair Foundry, Polymers and Automation described. There were applied the preforms characterized by porosities of 90% and 80%, what after squeeze casting with liquid EN AC - 44200 Al alloy produces the composite materials containing 10 vol. and 20 vol.% of fiber strengthening. The structural phenomena at the interface of strengthened alloy investigated with the optical and electron microscopy are discussed and the mechanical properties of manufactured composite materials are shown.


2013 ◽  
Vol 804 ◽  
pp. 52-56
Author(s):  
Yan Ping Feng ◽  
Zhi Wen Qiu ◽  
Xiao Bin Ma ◽  
Lei Zhao ◽  
Xin Chao Chen ◽  
...  

In order to lay raw materials foundation for increasing the performance of insulating brick with the low grade quartz sand along the Yangtze River, the quartz porous ceramic materials was researched in this paper. The results show the porosity of the porous quartz ceramics decreased with an increase in the sintering temperature. The pore is like the bowl shape, and the pore is closed pore, which is help to improve the heat insulation property of quartz porous ceramics. The CaSiO4 is produced in the ceramics after sintering processing. The shape is better, and the microstructure is circular and symmetrical pore, which is help to improve the mechanical property of quartz porous ceramics.


2016 ◽  
Vol 690 ◽  
pp. 150-155 ◽  
Author(s):  
Toyohiko Sugiyama ◽  
Keiji Kusumoto ◽  
Masayoshi Ohashi ◽  
Akinori Kamiya

The global warming is one of the most serious problems. The decrease of CO2 emissions in our daily life is an important subject today. Recently, an application of water retentive materials as a paving material has attracted a great deal of attention in Japan. This material is effective for reducing heat island phenomenon, which is also a recent problem in many cities in Japan. Water retained in the material during rainfall evaporates when heated by sunshine. The latent heat absorbed by evaporating water works to cool the surroundings. The water retentive ceramic products are expected to be useful for building materials as well as pavements. Several performances are required on the water retentive ceramics when it is used as building materials. Its cost and quality are the important factors. Porous ceramic materials formed by pressing without firing is one of ideal low cost and eco-friendly candidates. The porous ceramics is also expected to be produced from recycled ceramic materials. By optimizing its composition and forming method, a water retentive material with high performance was developed. The trial product had the properties as follows; fracture toughness: 1300N, bending strength: 175N/cm, water absorption: larger than 30%, and precision in size (length): +-0.5mm for 150mm. The product showed also enough frost resistance. In this paper, the fundamental properties of the porous ceramics prepared without firing are discussed with referring to the results of the field experiments.Another subject recently studied by several tile manufactures in Japan is the glazed tile with high solar reflectance. The exterior walls covered with such a high solar reflectance tile keeps the surface temperature of the wall lower under the strong sunshine of summer. It is effective against heat-island phenomenon. In this paper, the outline of the research results on visible and infrared reflectance of many kinds of glazes is also discussed.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Liliana Ávila Córdoba ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera Díaz ◽  
Fernando Ureña Nuñez ◽  
Alejandro Loza Yañez

Concretes consisting of portland cement (OPC), silica sand, gravel, water, and recycled PET particles were developed. Specimens without PET particles were prepared for comparison. Curing times, PET particle sizes, and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and Young modulus were determined. Morphological and chemical compositions of recycled PET particles were seen in a scanning electron microscopy. Results show that smaller PET particle sizes in lower concentrations generate improvements on compressive strength and strain, and Young’s modulus decreases when the size of PET particles used was increased.


Author(s):  
Joao Roberto Sartori Moreno ◽  
Rafael Claudiano de Moraes ◽  
Joao Paulo de Oliveira Paschoal ◽  
Rodrigo Henrique Lopes

The metallic foams have lower density, and important physical, mechanical, thermal and acoustic properties, has been highlighted in its use in innovative technologies. As a subgroup of the class of metallic foams, the syntactic metallic foams which consists of the addition of hollow ceramic balloons in a metallic matrix in aluminum Al-5052 by process of tixoinfiltration. The microstructure was studied by optical and electron microscopy extended by energy-dispersive X-ray spectrometry, while the basic mechanical properties were mapped by standardized compression tests. Therefore, a syntactic foam design was developed in this work, where we obtained a 30% reduction in density and a reasonable increase in hardness due to the homogeneous dispersion of the ceramic balloons


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