scholarly journals SYNTHESIS OF HIGH-STRENGTH CERAMICS BASED ON TECHNOGENIC WASTE CONTAINING ALUMINUM OXIDE

2020 ◽  
Vol 2020 (3) ◽  
pp. 30-32

The aim of this work is to synthesize wear-resistant and heat-resistant ceramics based on aluminum oxide. The manmade aluminum-containing waste of the Shurtan gas chemical complex was used as a source of aluminum oxide. In the work, the dependences «composition-structure», «composition-property» and «property-size of particles» were obtained, obtained by the method of heliomaterials science, namely by melting raw materials in a stream of concentrated solar radiation of high density (350 W/cm2) with subsequent quenching of the melt into water (103 deg/s). It is shown that the wear resistance and heat resistance of the material sharply increase when the content in the mass is more than 80% of aluminum oxide.

2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2910
Author(s):  
Chaoyi Ding ◽  
Chun Liu ◽  
Ligang Zhang ◽  
Di Wu ◽  
Libin Liu

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.


2015 ◽  
Vol 1119 ◽  
pp. 752-755
Author(s):  
Chang Zheng Sun ◽  
Zheng Wang

Optimization of mix proportion parameter ,Using ordinary raw materials makes a C80 high performance self-compacting concrete;By joining a homemade perceptual expansion agent, significantly improve the early strength of concrete and effective to solve the high strength of self-compacting concrete caused by gelled material consumption big contraction;Further study on the working performance of high-strength self-compacting concrete, age strength, analysis the influence factors of concrete are discussed.


2021 ◽  
Vol 320 ◽  
pp. 181-185
Author(s):  
Elvija Namsone ◽  
Genadijs Sahmenko ◽  
Irina Shvetsova ◽  
Aleksandrs Korjakins

Because of low calcination temperature, magnesia binders are attributed as low-CO2 emission materials that can benefit the environment by reducing the energy consumption of building sector. Portland cement in different areas of construction can be replaced by magnesia binder which do not require autoclave treatment for hardening, it has low thermal conductivity and high strength properties. Magnesium-based materials are characterized by decorativeness and ecological compatibility.The experimental part of this research is based on the preparation of magnesia binders by adding raw materials and calcinated products and caustic magnesia. The aim of this study was to obtain low-CO2 emission and eco-friendly material using local dolomite waste materials, comparing physical, mechanical, thermal properties of magnesium binders.


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.


2019 ◽  
Vol 51 (3) ◽  
pp. 285-294
Author(s):  
Dang Wei ◽  
H.-Y. He

High strength lightweight glass-ceramics were fabricated with coal gangue and clay as main raw materials. The utilization ratio of coal gangue, the ratio of the coal gangue with clay, mineralization agents, forming process and sintering process on the properties of the fabricated glass-ceramics were optimized. The utilization ratio of coal gangue reached 75, and the ratio of coal gangue to clay was 3/1, as an optimal property was observed. The optimal sintering temperature was found to be 1370?C. At this optimal temperature, the sintered glass-ceramics showed the main phase of mullite and spindle and so showed high strength, low density, and low water absorbance. The appropriate amounts of codoping of the TiO2, ZnO, and MnO2/dolomite as mineralization agents obviously enhanced the properties of the glass-ceramics. Process optimizations further determined reasonable and optimal process parameters. The high strength lightweight glass-ceramics fabricated in this work may be very suitable for various applications including building materials, cooking ceramics, and proppant materials, et al.


Author(s):  
A. A. Kazubov ◽  
D. A. Mironov

Agriculture is the most important branch of the national economy, providing the population of our country with food and obtaining raw materials for a number of industries. The role of agriculture in the economy of Russia and its regions shows the structure and level of development of the state. It is impossible to get a good harvest without proper cultivation of the land. Cultivation of any crops begins with basic tillage, which is one of the most time-consuming operations. For this purpose, mounted and semi-mounted ploughshares are used. One of the effective ways to reduce the energy intensity of the main tillage process is chisel-shaped ploughshares with a protruding toe (chisel), which is located below the blade by 20 … 25 mm. Due to this, the sinking capacity of the hull and its resource are improved. To achieve this goal, such methods are used as the influx of metal in the field-cut zone, which increases its thickness, the surfacing of the nose part, which increases wear resistance and, accordingly, reduces wear of the sock in thickness, welding to the sock with a plate made of a more high-strength material [1].


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5575
Author(s):  
Aleksandr Tolstoy ◽  
Valery Lesovik ◽  
Roman Fediuk ◽  
Mugahed Amran ◽  
Murali Gunasekaran ◽  
...  

Quartz sandstone (QS) is a mine waste; therefore, its use in construction allows for both reducing the cost of the concrete and contributing to the utilization of waste. The scientific originality of this study is the identification of models of the effect of QS aggregate on the physicomechanical, durability characteristics, and eco-safety of greener high-strength concrete. The study used an energy-efficient method of non-thermal effects of electromagnetic pulses on the destruction mechanisms of quartz-containing raw materials. The characteristics of quartzite sandstone aggregates, including the natural activity of radionuclides, were comprehensively studied. The features of concrete hardening, including the formation of an interfacial transition zone between the aggregate and the cement matrix, were studied, taking into account the chemical and morphological features of quartzite sandstone. In addition, the microstructural and morphological properties of concrete were determined after a 28 day curing. In this study, the behaviors of the concrete with QS aggregate were investigated, bearing in mind the provisions of geomimetics science on the affinity of structures. The results obtained showed that the QS aggregate had the activity of natural radionuclides 3–4 times lower compared to traditional aggregates. Efficient greener concrete with a 46.3 MPa compressive strength, water permeability grade W14, and freeze–thaw resistance of 300 cycles were also obtained, demonstrating that the performance of this greener concrete was comparable to that of traditional concrete with more expensive granite or gabbro diabase aggregates.


2010 ◽  
Vol 163-167 ◽  
pp. 1651-1654 ◽  
Author(s):  
Jin Bang Wang ◽  
Zong Hui Zhou

Several series of concrete aggregates with different content of steel slag, blast furnace slag, coal gangue and fly ash were prepared. The reasonable ratio of raw materials and process parameters to prepare the aggregates were determined by measuring the water absorption, crush indicators and apparent density of the aggregates. The mineral composition and morphology of the aggregates were analyzed by XRD, SEM and EDS. The results showed the aggregate with about 30% steel slag, 50% slag, 20% gangue, and calcined at 1300°C for 90 minutes had the best performance. The water absorption of the aggregate is about 1.55% which is lower than that of the natural aggregates (about 2.2% on average). Both the crushing index (about 11.39%) and the apparent density (2672 kg/m3) of the aggregate meet the requirements of national standards.


2019 ◽  
Vol 895 ◽  
pp. 83-89 ◽  
Author(s):  
Shivani Gupta ◽  
Apurbba Kumar Sharma

The serious diseases and accidents are the leading causes for the surgeries/transplantation in human body. In present time, a large proportion of world population is facing arthritis problems that lead to partial/total knee arthroplasty and total hip arthroplasty. The implants used in the arthroplasty require high strength, high corrosion and wear resistance and longer life span in a working environment. The quality of fabricated implants significantly depends upon the manufacturing methods used to process the raw materials. In present time, various sintering techniques are popularly used to produced implants owing to improved product quality; however, artificial implant manufacturing industry is looking for more energy efficient, time saving and eco-friendly processing techniques which can offer implants at economical cost along with adequate quality. The present article reviews an overview of different sintering techniques used for producing biomedical implants have been presented. The limitations of these processes have been highlighted and the potential of microwave sintering to address these challenges has been identified. Advantages of using microwave sintering over conventional sintering are also discussed in terms of microstructures, mechanical properties and process efficiency. It has been realized that microwave sintering has potential to cater the needs of the industry for processing of biomaterials as a time saving, energy efficient and environment friendly sintering technique as compare to conventional sintering.


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