scholarly journals Calciothermic powders of rare metals and intermetallic compounds

2020 ◽  
pp. 31-50
Author(s):  
A. V. Kasimtsev ◽  
S. N. Yudin ◽  
Yu. V. Levinsky
Keyword(s):  
Composite Materials ◽  
Intermetallic Compounds ◽  
Raw Materials ◽  
Synthesis Method ◽  
Reduction Process ◽  
Calcium Carbide ◽  
Calcium Hydride ◽  
Rare Metals ◽  
Technical Literature ◽  
Calciothermic Reduction

This paper presents a profound review of scientific and technical literature on the issues of calciothermic production of powders of rare metals, intermetallic compounds, composite materials and refractory oxygen-free compounds (carbides, nitrides). Calciothermic reduction is a metallothermic synthesis method for those substances where calcium or its derivatives, such as calcium hydride or calcium carbide, are used as a reducing agent. Thermodynamics aspects of a reduction process are covered in the paper broadly, with particular emphasis on assessing the reduction depth of original oxide raw materials, as TiO2. The mechanism and kinetics of calciothermic synthesis of single-component and multi-component alloys are described. Presented are both technological means of obtaining materials and hardware resources of many varieties of calciothermic method. The key features of the work are generalization and systematization of properties (chemical, physical, technological) of materials synthesized by calciothermic method. The data are accumulated in the appropriate tables and divided by substance classes (powders of metals and alloys, powders of intermetallic compounds, powders of carbides, powders of nitrides, and powders of composite materials). Methods of calciothermic powder making in case of the singlecomponent and complex multi-component systems are briefly described. This work will be interesting to the students of metallurgical profile and specialists whose scientific interests are in the field of material synthesis by methods of powder metallurgy.

Preparation of Al2O3 Nano-Particles Reinforced Fe-Based Composite Materials via In Situ Synthesis

2012 ◽  
Vol 476-478 ◽  
pp. 1287-1290 ◽  
Author(s):  
Rui Rui Fan ◽  
Yan Li ◽  
Liu Jie Xu ◽  
Shi Zhong Wei
Keyword(s):  
Composite Materials ◽  
Raw Materials ◽  
Synthesis Method ◽  
In Situ Synthesis ◽  
Nano Particles ◽  
Micro Hardness ◽  
Quenching Temperature ◽  
Before And After ◽  
The Matrix

Al2O3 reinforced iron based composite were prepared via in-situ synthesis with aluminum nitrate, citric acid and iron powder as raw materials, a little C and Mo as additive. The influences of the contents of Al2O3, C and Mo on the microstructure and micro-hardness of the Fe based composites were characterized by XRD, SEM, TEM and micro-hardness tester. The results showed that the Fe-based composite materials with high bonding strength between matrix and Al2O3 can be prepared by in situ synthesis method. The best ratio of the nine Al2O3 particles reinforced Fe-based composite materials in three groups is 3vol. % C, 5vol. % or 7vol. % Al2O3, sintering temperature is 1300°C and quenching temperature is 900°C. The microstructure of the matrix without C addition is ferrite before and after quenching; the microstructure of the matrix with C addition is pearlite before quenching, and the microstructure become to martensite after quenching, the α-Al2O3 and FeC3 are reinforced phases. The microstructure of the matrix with Mo addition is ferrite and FeAl2O4 before and after quenching.

scholarly journals Preparation of rare earth - transition metal (RE: Y, Tm: Co) intermetallic compounds by calciothermic reduction diffusion process

2014 ◽  
Vol 20 (1) ◽  
pp. 35-40 ◽  
Author(s):  
M. Ilayaraja ◽  
L. John Berchmans ◽  
Sankara Raman Sankaranarayanan
Keyword(s):  
Rare Earth ◽  
Intermetallic Compounds ◽  
Raw Materials ◽  
Argon Atmosphere ◽  
Metallic Cobalt ◽  
Optical Components ◽  
Unreacted Core ◽  
Unreacted Core Model ◽  
Calciothermic Reduction ◽  
Metallic Calcium

Rare earth cobalt alloys have many special magnetic properties and can be used to prepare magnetic and magneto-optical components. The yttrium – cobalt intermetallic compounds are prepared by calciothermic reduction – diffusion (CRD) process at temperature of 1000ºC, under argon atmosphere. Yttrium oxide, metallic cobalt powder, metallic calcium are used as raw materials in this process. Calcium acts as the reductant, which is used to prepare the YCo5 magnetic material. XRD, SEM, EDAX and some thermodynamic valuation have been carried out on the products. The chemical reactions controlled by unreacted core model theory were studied.

Bamboo Waste-based Bio-composite Substance: An application for Low-cost Construction Materials

2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero
Keyword(s):  
Composite Materials ◽  
Sea Water ◽  
Raw Materials ◽  
Low Cost ◽  
Construction Materials ◽  
Single Layer ◽  
High Strength ◽  
Green Technology ◽  
Experimental Medium ◽  
Natural Treatment

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.

scholarly journals Recent Advances in Fabrication of Non-Isocyanate Polyurethane-Based Composite Materials

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3497
Author(s):  
Piotr Stachak ◽  
Izabela Łukaszewska ◽  
Edyta Hebda ◽  
Krzysztof Pielichowski
Keyword(s):  
Raw Materials ◽  
Synthesis Method ◽  
Polymeric Materials ◽  
Original Research ◽  
Significant Group ◽  
Oh Groups ◽  
New Class ◽  
Hazardous Chemical ◽  
Wide Range

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.

Influence of the synthesis method of tert-butylated triphenyl phosphates on the operational properties of fire-resistant fluids

2021 ◽  
Vol 02 ◽  
pp. 32-37
Author(s):  
A.S. Medzhibovskiy ◽  
◽  
A.S. Kolokolnikov ◽  
A.O. Savchenko ◽  
G.A. Poldushova ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Power Plants ◽  
Phosphorus Oxychloride ◽  
Raw Materials ◽  
Hydrolytic Stability ◽  
Synthesis Method ◽  
Acid Number ◽  
Release Time ◽  
Triphenyl Phosphate ◽  
Prolonged Contact

Three substituted aryl esters of orthophosphoric acid are the base component of fire-resistant fluids used in the lubricating and electro-hydraulic control system at steam and gas turbines of power plants. In this paper, we studied the possibility of improving the physicochemical and performance properties of phosphates, which are made of the raw materials available in the Russian Federation: phenol and 4-tert-butylphenol by reducing the content of an undesirable component - unsubstituted triphenyl phosphate, which is particularly vulnerable towards water. According to the results of the work, the conclusions were made: - a decrease in the content of triphenyl phosphate to a level of 1% and below leads to some improvement (reduction) of the air release time and an increase in the hydrolytic stability (represented as reducing the change in acid number after prolonged contact with water) of the fire-resistant fluid based on mixed esters. The degree of change of these properties is quantified. - it is possible to achieve the minimum content of triphenyl phosphate by changing the phosphorylation technology. By carrying out the process stepwise, the possibility of the interaction of phosphorus oxychloride with unsubstituted phenol is substantially eliminated, that is why there is almost no probability of an undesirable component formation in the resulting mixture of esters.

scholarly journals Semisolid State Sintering Behavior of Aluminum–Stainless Steel 316L Composite Materials by Powder Metallurgy

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1473 ◽  
Author(s):  
Kwangjae Park ◽  
Dasom Kim ◽  
Kyungju Kim ◽  
Seungchan Cho ◽  
Kenta Takagi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Intermetallic Compounds ◽  
Vickers Hardness ◽  
Raw Materials ◽  
High Hardness ◽  
Engineering Industry ◽  
Sintering Behavior ◽  
Semisolid State ◽  
Stainless Steel 316L ◽  
X Ray

Aluminum (Al)-stainless steel 316L (SUS316L) composites were successfully fabricated by the spark plasma sintering process (SPS) using pure Al and SUS316L powders as raw materials. The Al-SUS316L composite powder comprising Al with 50 vol.% of SUS316L was prepared by a ball milling process. Subsequently, it was sintered at 630 °C at a pressure of 200 MPa and held for 5 min in a semisolid state. The X-ray diffraction (XRD) patterns show that intermetallic compounds such as Al13Fe4 and AlFe3 were created in the Al-SUS316L composite because the Al and SUS316L particles reacted together during the SPS process. The presence of these intermetallic compounds was also confirmed by using XRD, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and EDS mapping. The mechanical hardness of the Al-SUS316L composites was analyzed by a Vickers hardness tester. Surprisingly, the Al-SU316L composite exhibited a Vickers hardness of about 620 HV. It can be concluded that the Al-SUS316L composites fabricated by the SPS process are lightweight and high-hardness materials that could be applied in the engineering industry such as in automobiles, aerospace, and shipbuilding.

Development of green nanocomposites reinforced by cellulose nanofibers extracted from paper sludge

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540025 ◽  
Author(s):  
Hitoshi Takagi ◽  
Antonio N. Nakagaito ◽  
Kazuya Kusaka ◽  
Yuya Muneta
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Mechanical Treatment ◽  
Raw Materials ◽  
Cellulose Nanofibers ◽  
Tensile Tests ◽  
Cellulose Nanofiber ◽  
Paper Sludge ◽  
Reinforcing Effect ◽  
Mechanical And Physical Properties

Cellulose nanofibers have been showing much greater potential to enhance the mechanical and physical properties of polymer-based composite materials. The purpose of this study is to extract the cellulose nanofibers from waste bio-resources; such as waste newspaper and paper sludge. The cellulosic raw materials were treated chemically and physically in order to extract individualized cellulose nanofiber. The combination of acid hydrolysis and following mechanical treatment resulted in the extraction of cellulose nanofibers having diameter of about 40 nm. In order to examine the reinforcing effect of the extracted cellulose nanofibers, fully biodegradable green nanocomposites were fabricated by composing polyvinyl alcohol (PVA) resin with the extracted cellulose nanofibers, and then the tensile tests were conducted. The results showed that the enhancement in mechanical properties was successfully obtained in the cellulose nanofiber/PVA green nanocomposites.

Investigation of Magnetorheological Suspensions by Optical Methods

2009 ◽  
Vol 152-153 ◽  
pp. 151-154
Author(s):  
L.V. Nikitin ◽  
D.N. Kudryavcev ◽  
I.V. Shashkov ◽  
A.P. Kazakov
Keyword(s):  
Magnetic Field ◽  
Composite Materials ◽  
Uniform Magnetic Field ◽  
Magnetic Particles ◽  
Raw Materials ◽  
Optical Methods ◽  
Magnetic Clusters ◽  
Liquid Polymer ◽  
Synthetic Rubber ◽  
Magnetorheological Suspensions

In this work we studied magnetorheological suspensions, which are produced by dispersion of magnetic particles in liquid polymer matrix, based on natural and synthetic rubber. Such suspensions are the raw materials for creation of new high-elastic magneto-controlled composite materials (magnitoelastics[1-4]). Processes of aggregation and structurization of magnetic particles in suspension are also examined. We discovered that motion of magnetic clusters in oligomer solution has interrupted character. Such behavior can be explained by interaction of magnetic clusters moving in not uniform magnetic field with polymer net fragments. Evaluation of polymer net’s elastic properties was calculated.

scholarly journals Tension mechanical properties of recycled glass-epoxy composite material

2012 ◽  
pp. 189-198 ◽  
Author(s):  
Jelena Petrovic ◽  
Darko Ljubic ◽  
Marina Stamenovic ◽  
Ivana Dimic ◽  
Slavisa Putic
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Material ◽  
Composite Materials ◽  
Modulus Of Elasticity ◽  
Epoxy Composite ◽  
Raw Materials ◽  
Mechanical Tests ◽  
Recycled Glass ◽  
Before And After

The significance of composite materials and their applications are mainly due to their good properties. This imposes the need for their recycling, thus extending their lifetime. Once used composite material will be disposed as a waste at the end of it service life. After recycling, this kind of waste can be used as raw materials for the production of same material, which raises their applicability. This indicates a great importance of recycling as a method of the renowal of composite materials. This study represents a contribution to the field of mechanical properties of the recycled composite materials. The tension mechanical properties (tensile strength and modulus of elasticity) of once used and disposed glass-epoxy composite material were compared before and after the recycling. The obtained results from mechanical tests confirmed that the applied recycling method was suitable for glass-epoxy composite materials. In respect to the tensile strength and modulus of elasticity it can be further assessed the possibility of use of recycled glass-epoxy composite materials.

scholarly journals Food fortification – a modern principle of the food industry

2020 ◽  
Vol 12 ◽  
pp. 70-76
Author(s):  
V.G. Kaishev ◽  
Keyword(s):  
Raw Materials ◽  
Caloric Intake ◽  
Food Products ◽  
Technical Literature ◽  
Short Supply ◽  
Mass Consumption ◽  
Organoleptic Characteristics ◽  
Physiological Properties ◽  
Physico Chemical ◽  
New Generation

Aim. To analyze the scientific and technical literature and identify ways to create a new generation of mass-consumption food products enriched with vital nutrients. Discussion. The main malnutrition of the Russian population is the excess of caloric intake over an indicator of the level of energy consumption. One of the ways to solve this problem is the production of functional food products or enriched functional products. The essence of this is that only those micronutrients that are really in short supply should be used in the fortification of products. These should be products of mass consumption, and especially those that undergo refining, which results in the loss of micronutrients. The use of raw materials and ingredients only of natural (animal, vegetable, mineral) origin, allows you to create active complexes that qualitatively change the physiological properties of the product, and can affect many product characteristics and processes such as physico-chemical, structural-mechanical and organoleptic characteristics of the product, the processes of color formation, fermentation, oxidation, storage capacity. However, sometimes a strong passion for enriching the product with useful macro- and micronutrients affects the taste characteristics. Conclusion. When developing recipes and technologies for new-generation products, it is necessary that the enrichment of the product with important and necessary elements does not worsen the organoleptic characteristics. At the same time, it is necessary to ensure the safety of products without compromising consumer properties. The diet should contain all the necessary nutrients (nutrients) for a person in sufficient quantities and balanced with each other in the most favorable proportions.

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