scholarly journals Revealing specific features of structure formation in composites based on nanopowders of synthesized zirconium dioxide

2021 ◽  
Vol 5 (12(113)) ◽  
pp. 6-19
Author(s):  
Edwin Gevorkyan ◽  
Volodymyr Nerubatskyi ◽  
Volodymyr Chyshkala ◽  
Oksana Morozova
Keyword(s):  
Mechanical Properties ◽  
Crack Resistance ◽  
Electric Current ◽  
Zirconium Dioxide ◽  
Physical And Mechanical Properties ◽  
Ammonia Solution ◽  
Sintering Process ◽  
Simultaneous Inhibition ◽  
Fluoride Salts ◽  
Sintering Method

Peculiarities of formation of microstructure in composites based on chemically synthesized zirconium nanopowders obtained by the method of decomposition from fluoride salts were considered. Hydrofluoric acid, concentrated nitric acid, aqueous ammonia solution, metallic zirconium, and polyvinyl alcohol were used. It was established that the reduction of porosity in nanopowders in the sintering process is the main problem in the formation of high-density materials. Analysis of various initial nanopowders, their morphology, and features of sintering by the method of hot pressing with direct transmission of electric current was made. Peculiarities of obtaining the composites based on them with the addition of Al2O3 nanopowders applying the electric sintering method were considered. It was shown that the increase in the content of alumina nano additives leads to an increase in strength and crack resistance of the samples due to simultaneous inhibition of abnormal grain growth and formation of a finer structure with a high content of tetragonal phase. The influence of sintering modes on the formation of the microstructure of zirconium nanopowders has been studied for different contents of alumina additives. Electric current promotes the surface activity of nanopowders and its variable value promotes partial fragmentation of agglomerated grains thus affecting the composite structure. Physical-mechanical properties of the obtained samples, optimal compositions of mixtures, and possibilities of improving some parameters were determined. It was found that nanopowders of zirconium dioxide obtained by the method of decomposition from fluoride salts are quite suitable for the production of composite materials with high physical and mechanical properties. They can compete with imported analogs and enable obtaining of crack resistance of 7.8 MPa·m1/2 and strength of 820 MPa.

Microstructure and Mechanical Properties of Cement/Fly Ash/Natural Rubber Composites

2017 ◽  
Vol 866 ◽  
pp. 195-198
Author(s):  
Rakchanok Promudom ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Portland Cement ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Physical And Mechanical Properties ◽  
Ammonia Solution ◽  
Rubber Latex ◽  
Water To Cement Ratio ◽  
Natural Rubber Composites

The physical and mechanical properties of Portland cement (PC) - natural rubber latex (NRL) - fly ash (FA) composites have been investigated. The latex per cement ratios that use in this experiment are 0, 5, 7.5 and 10% by weight of cement. Portland cement (PC) was partially replaced with fly ash 0-40% by weight of binder. Water to cement ratio were used in range of 0.305-0.385 (by weight not include water in latex). Nonionic surfactant was added in cement before mixed with natural rubber latex. In addition, to provide latex from natural rubber latex, the ammonia solution is added into natural rubber. The specimens were packing into an iron mold which sample size of 4x4x16 cm3. Moreover, the PC-NRL-FA composites were cured in water for 7 and 28 days at room temperature before measurement. Then, mechanical properties (flexural strength) and microstructure were studied.

A Study of Different Sintering Routes on Properties of Ni-Al2O3 Hydrogen Separation Membrane

2010 ◽  
Vol 434-435 ◽  
pp. 514-517
Author(s):  
Supawan Vichaphund ◽  
Duangduen Atong
Keyword(s):  
Mechanical Properties ◽  
Ball Milling ◽  
Nickel Powder ◽  
Physical And Mechanical Properties ◽  
Hydrogen Separation ◽  
Alumina Powder ◽  
Sintering Process ◽  
Separation Membrane ◽  
Sintering Conditions ◽  
Hydrogen Separation Membrane

This work aimed to investigate the effect of different sintering routes on properties of Ni-Al2O3 membrane. Alumina powder was mixed with 10 wt% nickel powder by dried ball-milling. Then, the mixture powder was uniaxially pressed to a bar shape and sintered via different sintering conditions. First route, the Ni-Al2O3 specimen was sintered at 1300°C for 2 h under air and then reduced at 900°C for 2 h under H2 atmosphere. Second route, the specimen was sintered at 1300°C for 2 h under argon. After sintering process, the physical and mechanical properties of membrane obtained from two routes were compared and discussed.

Physical and Mechanical Properties of WC-Co Submicron Powders Using P/M Technique

2014 ◽  
Vol 879 ◽  
pp. 12-15 ◽  
Author(s):  
Ahmad Aswad Mahaidin ◽  
Mohd Asri Selamat ◽  
Samsiah Abdul Manaf ◽  
Talib Ria Jaafar
Keyword(s):  
Mechanical Properties ◽  
Grain Growth ◽  
Vanadium Carbide ◽  
Physical And Mechanical Properties ◽  
Growth Inhibitor ◽  
Cold Isostatic Pressing ◽  
Mixing Process ◽  
Sintering Process ◽  
Grain Growth Inhibitor ◽  
Work Done

The properties of WC-Co are greatly improved with the use of submicron powders. However, grain growth tends to occur during the sintering process which causes the properties to deteriorate to some extent. Free carbon and vanadium carbide are added in this study to serve as grain growth inhibitor. The effect of these two materials is evaluated based on WC-Co properties. In this work, the powders are mixed together via wet mixing process, compacted and undergo cold-isostatic pressing (CIP) before the samples are sintered in the temperature range of 1350-1450°C under nitrogen-based atmosphere. The physical and mechanical properties of the WC-Co sintered powders were analysed. Based on the work done, the WC-Co-C has a better properties compared to WC-Co-VC.

scholarly journals Experimental of Mechanical Properties in Glass Fiber by using Epoxy and Polyester Resin

2020 ◽  
Vol 8 (4S5) ◽  
pp. 299-301
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Zirconium Dioxide ◽  
Impact Test ◽  
Polyester Resin ◽  
Glass Fibers ◽  
Physical And Mechanical Properties ◽  
Hardness Test ◽  
Water Absorption Test ◽  
Test Impact

Alkali Resistant Glass Fibers are designed specifically for use in concrete. It is made from a specially developed glass composition of zirconium dioxide which is appropriately used in concrete. It is to evaluate and compare the physical and mechanical properties of laminates prepared of different composition of Glass fiber. In this experiment, two specimens with different composition was taken and prepared by using hand layup method. Tensile test, Impact test and Brinell hardness test were carried out and their performances were evaluated. In this experiment, composite was subjected to water absorption test. From the result, property of two specimen was compared and analyzed.

scholarly journals Effects of TiAl Alloy as a Binder on Cubic Boron Nitride Composites

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6335
Author(s):  
Yuxi Liu ◽  
Wei Zhang ◽  
Yingbo Peng ◽  
Guojiang Fan ◽  
Bin Liu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Boron Nitride ◽  
Tial Alloy ◽  
Cubic Boron Nitride ◽  
Sintering Process ◽  
Good Oxidation Resistance ◽  
Tial Intermetallics ◽  
High Pressure Sintering ◽  
Sintering Method

Owing to their extreme hardness, cubic boron nitride (cBN) composites are widely used in cutting applications. The performance of cBN composites is closely related to the characteristics of the binder. Therefore, novel binders must be developed to improve the performance of cBN composites. In the present work, TiAl intermetallics were used as binders to fabricate cBN composites by employing a high-temperature and high-pressure sintering method. The phase transformation, sintering reaction mechanism, thermal stability, and mechanical properties of the resultant cBN composites were investigated. It was found that during the sintering process, Ti atoms preferentially reacted with boron nitride particles, whereas Al atoms enriched and transformed into TiAl3 phases and formed cBN/AlN, AlB2/TiN, and TiB2/TiAl3-layered structures eventually. The composites maintained good oxidation resistance at 1200 °C. A decrease in the particle size of the TiAl binder improved the uniformity of particle size distribution and increased the flexural strength of the composites.

scholarly journals Electrodischarge machining of silicon nitride composites and silicon carbide composites

Mechanik ◽  
2019 ◽  
Vol 92 (2) ◽  
pp. 115-118
Author(s):  
Andrzej Nowakowski ◽  
Piotr Putyra ◽  
Tadeusz Krzywda
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Silicon Carbide ◽  
Ceramic Composite ◽  
Physical And Mechanical Properties ◽  
Electro Discharge Machining ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Ceramic Composite Materials ◽  
Sintering Method

The paper presents the results of physical and mechanical properties of the and Si3N4 and SiC matrix ceramics with additives of good electrical conductivity carbides, nitrides and borides phases. The density, Young’s modulus, hardness HV1 and electrical conductivity of each material were investigated. Ceramic composite materials with the participation of the conductive phases have been produced using SPS (spark plasma sintering) method. Materials characterized by good electrical conductivity were shaped using EDM (electro discharge machining) method.

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