Acoustic control of the strengthening of building ceramics obtained by extrusion through an ultrasonic die

2021 ◽  
Vol 87 (2) ◽  
pp. 25-32
Author(s):  
R. M. Nafikov ◽  
G. R. Faseeva ◽  
Yu. A. Zakharov

Extrusion through a die, vibrating with an ultrasonic frequency is a promising method for hardening ceramic materials (bricks, tiles, pipes, etc.). We present the results of studying low-frequency acoustic spectra of cylindrical samples of face brick ceramics reinforced by extrusion and addition of fiberglass waste. Correlations between structure changes in the obtained ceramics, parameters of the acoustic spectrum of the samples, and the destructive forces upon their compression (bending) in a press were analyzed. It is shown that ultrasonic extrusion increases the destruction force of the cylinders by 1 – 7 kN (~30 %) and thus shifts the frequency of the fundamental tones of transverse and longitudinal oscillations (6 and 17 kHz) with a coefficient of ~0.1 kHz/kN. The fiberglass particles strengthen the ceramics due to the formation of a needle-like crystalline bond during firing. At the same time, an increased addition of the fiberglass particles reduces the plasticity of the batch thus resulting in formation of the microcracks, cavities and internal stresses in the samples. The occurrence of internal defects shifts the frequency of longitudinal and transverse vibrations to a different extend, which can be used as an indicator of the defects present in the samples and provide the possible of their objective sorting and rejection. The vibration relaxation time (about 0.1 sec) does not change significantly under the described strengthening effects and being characterized by a wide scatter in each series of the samples cannot be considered an informative parameter. Thus, the effectiveness of the presented combined method of ceramics hardening can be accurately tested by the shift in the frequencies of longitudinal and transverse free vibrations of cylindrical specimens. The presented approach facilitates the process of developing new ceramic compositions and extrusion technology in conditions of depletion of sources of high-quality clay raw materials.

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3365
Author(s):  
Justyna Zygmuntowicz ◽  
Magdalena Gizowska ◽  
Justyna Tomaszewska ◽  
Paulina Piotrkiewicz ◽  
Radosław Żurowski ◽  
...  

This work focuses on research on obtaining and characterizing Al2O3/ZrO2 materials formed via slip casting method. The main emphasis in the research was placed on environmental aspects and those related to the practical use of ceramic materials. The goal was to analyze the environmental loads associated with the manufacturing of Al2O3/ZrO2 composites, as well as to determine the coefficient of thermal expansion of the obtained materials, classified as technical ceramics. This parameter is crucial in terms of their practical applications in high-temperature working conditions, e.g., as parts of industrial machines. The study reports on the four series of Al2O3/ZrO2 materials differing in the volume content of ZrO2. The sintering process was preceded by thermogravimetric measurements. The fabricated and sintered materials were characterized by dilatometric study, scanning electron microscopy, X-ray diffraction, and stereological analysis. Further, life cycle assessment was supplied. Based on dilatometric tests, it was observed that Al2O3/ZrO2 composites show a higher coefficient of thermal expansion than that resulting from the content of individual phases. The results of the life cycle analysis showed that the environmental loads (carbon footprint) resulting from the acquisition and processing of raw materials necessary for the production of sinters from Al2O3 and ZrO2 are comparable to those associated with the production of plastic products such as polypropylene or polyvinyl chloride.


1986 ◽  
Vol 72 ◽  
Author(s):  
Theresa L. Baker ◽  
Stephen W. Freiman

AbstractThis study involved the determination of the effects of composition and microstructure on the fracture toughness and susceptibility to environmentally enhanced crack growth of several ceramic materials used in multilayer capacitors. Indentation-fracture procedures were used to measure KIC as well as to assess the possible effects of internal stresses on the fracture behavior of these materials and to correlate dielectric aging phenomena with strength. The environmentally enhanced crack growth behavior of these materials was determined by conducting dynamic fatigue tests in water.


2012 ◽  
Vol 82 ◽  
pp. 32-37 ◽  
Author(s):  
Malgorzata Plonska ◽  
Wojciech A. Pisarski ◽  
Beata Wodecka-Dus ◽  
Lukasz Cienki

In the present work the influence of neodymium concentration (0-1at-%) and sintering conditions on 8/65/35 PLZT:Nd3+ ceramics were studied. All ceramic powders were synthesized by MOM technique from high purity raw materials (>99,9%), and subsequently sintered by free sintering and hot uniaxial pressing method. To analyze the powders and ceramics more the XRD, EDS SEM, and ferroelectric measurements were performed. Optical spectra were examined for all prepared samples, and their optical properties were analyzed using reflectance, excitation and luminescence measurements. The study gives a detailed account of the relationships between doping and preparing conditions on the basic physical and dielectric and optical properties of obtained ceramic materials.


2011 ◽  
Vol 295-297 ◽  
pp. 1860-1865 ◽  
Author(s):  
Zhi Zhang ◽  
Chao Liu ◽  
Gong Duan Fan ◽  
Jing Luo ◽  
Yan Dong Wang

The control parameters of the removal of Chlorella pyrenoidosa, which was irradiated by low frequency ultrasonic, is optimized by using single factor experiments and response surface methodology (RSM). First of all, the approximate ranges of the ultrasonic frequency, the ultrasonic power and the irradiation time were estimated with single factor experiments for the further experiments. And then the optimized values of the three control parameters were determined, which were analyzed by using central composite design (CCD) and RSM. The results showed that the removal rate of chlorophyll-a could reach to 64.1% after the irradiation for 6.34min by using ultrasonic of 77.7 kHz and 250W. Ultrasonic technology can remove Chlorella pyrenoidosa cells in water quickly and effectively, so as to achieve the purpose of water purification.


2021 ◽  
Vol 109 (1) ◽  
pp. 44-52
Author(s):  
K. Kostetska ◽  
◽  
I. Ulianych ◽  
V. Zheliezna ◽  
M. Holubiev ◽  
...  

Engineering in the technology of manufacture of extruded feed additives The aim of the work was to expand the range of animal feed and improve the technology of production of extruded feed mixture. Technology of use of preliminary preparation of raw materials: cleaning, reduction of quantity, its dosing according to the recipe, change and special means for improvement of technological authorities and increase of fodder value from processes: preliminary mixing, settling and extrusion of the mixture, cooling and grinding of the product depending on the purpose of the fodder Keywords: grain, fruit and vegetable raw materials, feed additives, extrusion technology, engineering.


2020 ◽  
Author(s):  
Carlos Galhano ◽  
Pedro Lamas ◽  
Diogo Seixas

The massive growth of the ceramic industry and the consequent demand for construction materials worldwide has motivated the search for alternative solutions aimed at reducing the use of mineral / natural resources as the main source of raw materials. One of the strategies frequently adopted by the scientific community is the reuse of industrial waste. It is beneficial not only to reduce the overexploitation of mineral resources but also to reduce the environmental, economic and social impacts resulting from their incorrect disposal/treatment and consequent deposition on land unsuitable or that purpose. Duetoconsiderationssuchasphysico-mechanical characteristics and the high production rate, two different types of industrial waste were selected for this work, ashes resulting from the burning of coal in thermoelectric power plant, commonly known as bottom ash (B), and the Marble Powder (MP). It was intended to test the technological feasibility of the manufacture of ceramic materials produced from clay mixtures containing these two residues. For this purpose, the fine fraction(<63μm)obtained from the sieving of the marbleresidue(MR)and slag(Bf)was used,aswellasacoarsergrainslagfractionrangingfrom63-125μm(Bg). The resulting test samples were subjected to a firing of 950 °C under an oxidizing atmosphere, following a primary drying process. Faced with the standard values, the new ceramic materials obtained from MP have seen their mechanical and porous characteristics decrease and increase, respectively. Atthesametime,althoughtheadditionofBinno way influenced the mechanical characteristics,a significant improvement the porous characteristic was observed. The incorporation of these residues produced a color very close to the original sample material. Keywords: industrial waste, ceramic, construction materials, bottom ash, Marble Powder


2003 ◽  
Vol 68 (6) ◽  
pp. 505-510 ◽  
Author(s):  
Branko Matovic ◽  
Snezana Boskovic ◽  
Mihovil Logar

Local and conventional raw materials?massive basalt from the Vrelo locality on Kopaonik mountain?have been used as starting materials to test their suitability for the production of glass-ceramics. Crystallization phenomena of glasses of the fused basalt rocks were studied by X-ray phase analysis optical microscopy and other techniques. Various heat treatments were used and their influences, on controlling the microstructures and properties of the products were studied with the aim of developing high strength glass-ceramic materials. Diopside CaMg(SiO3)2 and hypersthene ((Mg,Fe)SiO3) were identifies as the crystalline phases. The final products contained considerable amounts of a glassy phase. The crystalline size was in range of 8?480 ?m with plate or needle shape. Microhardness, crashing strength and wears resistence of the glass-ceramics ranged from 6.5?7.5, from 2000?6300 kg/cm2 and from 0.1?0.2 g/cm, respectively.


Author(s):  
Yu. V. Lykholat ◽  
N. O. Khromykh ◽  
T. Yu. Lykholat ◽  
M. I. Nedzvetska ◽  
O. A. Lykholat ◽  
...  

The introduction of fruit plants into a culture enriches the diversity of the species composition of the regional flora and at the same time creates an opportunity for expansion of the plant raw material base for the needs of the food industry, inclusion in a full-fledged functional nutrition of the population. Among the fruit plants of the Dniprovsk region, every year, more attention should be paid to introduced low-frequency non-traditional fruit species, in which the fruits, leaves, stems and other parts have high nutritional value and are the source of physiologically active compounds that have anti-cancer, antibacterial and anti-inflammatory properties, carry cardio protective, antihypertensive, anti-diabetic effects, stimulate the central nervous system, etc., and can contribute to the prevention and treatment of many diseases.   Antioxidants additives in the raw materials and finished products ensures their prevention damage, reduce losses, increase shelf life and production of high quality products which keep for a long time characteristics inherent fresh, complete products. Preservation, restoration and introduction to the culture of any species depends primarily on its ability to multiply seed and vegetative methods. A comparative analysis of the fruit and seed ability of Berberis L. representatives grown in the botanical garden of Oles Gonchar’  Dniprovsky National University was carried out. The use of integrated research methods made it possible to carry out an integrated assessment of the regenerative capacity of the investigated representatives of the Berberis L. and to establish their biological ability to seed propagation depending on the seed quality of the seeds. The seeds length varied from 4.5 mm (B. canadensis) to 5.2 mm (B. declinata, B. amurensis), width was from 1.8 mm (B. amurensis, B. vulgares) to 2.1 mm ( B. coreana). The weight of 1000 seeds, which, depending on their size and completeness, amounted to an average of 10.16 grams. Largest weight 1000 pcs. seed is marked in B. coreana. As a result of the total antioxidant ability of the fruits, the species examined can be arranged in the following order:  B. koreana > B. x declinata > B. vulgaris > B. amurensis > B. canadensis. When comparing total antioxidant capacity level of the plants, the highest indices were characteristic for B. koreana and B. x declinata fruits, which exceeded the values of other species in 1.7-1.9 times. The relatively low antioxidants concentration in B. amurensis fruits is offset by a greater weight of the fruits of this species.  In order to enrich the range of ornamental and fruit plants, it is expedient to introduce into production of new crops and to expand the species diversity of Berberis L. representatives. Barberry reproduction process depends on many factors related to the environment. All investigated representatives of the Berberis L. are promising for further use in the planting system and as fruit plants that can be included in the functional nutrition of the population and use in the food industry in the conditions of the Steppe Prydniprovya.


Cerâmica ◽  
2020 ◽  
Vol 66 (380) ◽  
pp. 413-420
Author(s):  
L. M. S. e Silva ◽  
R. S. Magalhães ◽  
W. C. Macedo ◽  
G. T. A. Santos ◽  
A. E. S. Albas ◽  
...  

Abstract Recycling has been pointed out as an alternative to the disposal of waste materials in industrial landfills. In the present study, the transformation of residues (discarded foundry sand - DFS, grits, and lime mud) in glass-ceramic materials is shown. The glasses were obtained by the melting/cooling method. The precursor materials, glasses, and glass-ceramics were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). The glassy materials were milled, pelleted, and thermally treated at the crystallization temperatures given by DSC data to obtain the glass-ceramics (885, 961, and 1090 ºC). The main formed phases were cristobalite, α-wollastonite (parawollastonite), and β-wollastonite (pseudowollastonite). The glass-ceramics showed very low water absorption and apparent porosity (0.26 to 0.88 wt% and 0.66 to 1.77 vol%, respectively). The results confirmed that the studied residues can be used as raw materials for the manufacture of vitreous and glass-ceramic materials.


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.


Sign in / Sign up

Export Citation Format

Share Document