Microstructure Characterization of Superfine WC-Co Powders

2013 ◽  
Vol 203-204 ◽  
pp. 351-354 ◽  
Author(s):  
Grzegorz Moskal ◽  
Krzysztof Szymański ◽  
Agnieszka Tomaszewska ◽  
Hanna Myalska
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Thermal Spraying ◽  
Point Of View ◽  
Microstructural Properties ◽  
Technological Properties ◽  
Composite Powders ◽  
Distribution Maps ◽  
Macro Scale

In this paper results of tests concerning the WC/Co fine-crystalline composite powders type 88/12 and 83/17 provided for thermal spraying of layers resistant to abrasion are presented. Tests which characterize basic technological properties were performed since these properties are essential from thermal spraying point of view. Microstructural properties are essential as well because they allow evaluation of morphology of powders by SEM method with an analysis of chemical composition in micro-areas. Moreover, the phase composition was characterized by XRD in macro scale and by EBSD in microareas including distribution maps of individual phase components in all particles of the powders.

Microstructural Characterization of Ni(Co)CrAlY Powders Designed for Thermal Spraying of Bondcoat for TBC Systems

2013 ◽  
Vol 203-204 ◽  
pp. 435-438 ◽  
Author(s):  
Grzegorz Moskal
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Thermal Spraying ◽  
Microstructural Characterization ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Microstructural Characteristics ◽  
Study Results ◽  
Tbc Systems

The paper presents the study results concerning microstructural characteristics of the Ni(Co)CrAlY type powders designed for the bondcoat spraying with the plasma method for TBC layers obtained by the atmospheric plasma spraying (APS). Three types of powders with the following chemical composition Ni-23Co-17Cr-12.5Al-0.45Y, Co-32Ni-21Cr-8Al-0.5Y and Ni-22Cr-10Al-Y were subjected to analysis. The assessment of surface morphology and inner structure of powders (SEM) was made. Chemical composition (EDX, OES-ICP) of the powders was determined. Phase composition by using XRD and EBSD methods was also analysed.

scholarly journals Production and investigation of powders for additive synthesis from a new beta-solidifying TiAl-based alloy

2021 ◽  
Vol 2144 (1) ◽  
pp. 012004
Author(s):  
P V Panin ◽  
I A Bogachev ◽  
E A Lukina
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Equilibrium Phase ◽  
Fold Increase ◽  
Induction Melting ◽  
Technological Properties ◽  
Powder Flowability ◽  
Powder Particles ◽  
Additive Synthesis ◽  
Composition Structure

Abstract Chemical composition, structure, and technological properties have been investigated for metal powder compositions (MPCs) of a new six-component TiAl-based alloy with Gd microadditions: Ti-31.0Al-2.5V-2.5Nb-2.5Cr-0.4Gd, wt.% (Ti-44.5Al-2V-1Nb-2Cr-0.1Gd, at.%). Three MPCs fractions (10–63, 40–100, 80–120 μm) were produced by electrode induction melting and inert gas atomization technique and targeted for the additive synthesis of parts. It is shown that the chemical composition of the MPCs for the main elements corresponds to that of the electrode. In contrast, a 1.5-fold increase of the oxygen content in the MPCs was observed, which is being the result of natural oxidation of powder particles upon air environment due to developed specific surface. It has been determined that the phase composition of the MPCs (γ+α(α2)+β) differs from the equilibrium phase composition of the electrode (γ+α2)+β0/B2) and corresponds to a rapidly quenched metastable state, which indicates high solidification rates in the atomization process, exceeding critical cooling rates of the alloy. The technological properties, specifically the powder flowability, were found to be improved for 40–100 and 80–120 μm fractions, making them applicable for additive synthesis of parts from the studied alloy by selective electron-beam melting method

scholarly journals Investigations of quartz raw materials from the locality of Rekovac muncipality

2019 ◽  
Vol 73 (4) ◽  
pp. 265-274
Author(s):  
Slavica Mihajlovic ◽  
Zivko Sekulic ◽  
Jovica Stojanovic ◽  
Vladan Kasic ◽  
Iroslav Sokic ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
Quartz Sand ◽  
Raw Materials ◽  
Construction Materials ◽  
Size Fraction ◽  
Point Of View ◽  
Raw Material ◽  
Potential Applications

Quality of raw materials, including quartz sand and quartzite, varies from one deposit to another. Furthermore, the material quality determines in which industrial branches it can be used after certain preparation processes. Potential applications of quartz raw materials are: in the construction and refractory industry, ceramics and glass industry, then in metallurgy, foundry and also in production of water treatment filters. Geological investigations of the central Serbia region, in the Rekovac municipality, resulted in identification of occurrence of quartz sand ("Ursula") and quartzite ("Velika Krusevica"). Preliminary laboratory tests and characterization of the quartz sand size fraction -0.63+0.1 mm confirmed the possibility of applying this size fraction in the construction materials industry, while the quartzite can be used in refractory, glass and metallurgy industries. After determining the geological reserve of quartz sand "Ursula" and quartzite "Velika Krusevica", detailed investigations are required. Quality conditions from the aspect of chemical composition and physical properties of quartz sand and quartzite are mostly clearly defined by a special standard for this purpose. On the other hand, there are also application areas where standards does not exist, but users define their quality conditions. This example is with the application of quartz sand in the production of water glass. Chemical composition as well is not always the determining factor for the application of quartz raw material. For example, for quartz sand used for sandblasting, grain form is essential. From the economic analysis point of view, the prices of quartz raw materials vary depending on their chemical and physical properties. After all, what needs to be pointed out is the fact that these raw materials are very widespread in nature and that their exploitation is quite simple. After the raw material is excavated, it is stored and further sieved, washed, dried and processed according to customer requirements. All of these processes are cheaper than preparing, for example, limestone, and significaly cheaper than preparation of metal ores.

Chemical Technological Characterization of Some Secondary Pulverous Materials Recycled in Metallurgy

2008 ◽  
Vol 59 (1) ◽  
pp. 92-96
Author(s):  
Constantin Predescu ◽  
Mirela Gabriela Sohaciu ◽  
Dana Serban ◽  
Maria Nicolae
Keyword(s):  
Chemical Composition ◽  
Point Of View ◽  
Scale Mixture ◽  
New Classification ◽  
Gas Removal ◽  
Scrap Iron ◽  
Impact Characteristics ◽  
Experimental Researches

Putting in practice the recycling projects of the damaging secondary powder products as dust, scale (mixture of oxides � fabrication defect appearing at rolling) or sand resulted in steel industry effluents removal, needs to be characterized from physical, chemical and technological point of view. This paper aims to realise a new classification of the damaging material and new definitions for their characteristics. The proposed groups are: producing characteristics, impact characteristics, removal characteristics and recycling valorisation characteristics. To underline the technological importance of the used characteristics as work instruments has been programmed experimental researches regarding the diminishing of the recycling of the dust and the sand obtained after the electric arc furnace gas removal and scale from rolling. The characteristics of recycling valorisation have been assessed: chemical composition and Zn assimilation ratio in the steel, the efficiency in liquid steel, the degree of replacing the scrap iron and the recycling chemical composition.

scholarly journals Electrochemical deposition and characterization of Ni-Mo alloy powders

2007 ◽  
Vol 1 (1-2) ◽  
pp. 11-17
Author(s):  
M.G. Pavlovic ◽  
B.M. Jovic ◽  
V.D. Jovic ◽  
U. Lacnjevac ◽  
V.M. Maksimovic
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Concentration Ratio ◽  
Xrd Analysis ◽  
Crystalline Powder ◽  
Powder Composition ◽  
Eds Analysis ◽  
N2 Atmosphere ◽  
Powder Particles

Electrodeposition of Ni-Mo alloy powders from ammonium sulfate and ammonium chloride containing electrolytes of different Ni/Mo ions concentration ratios was investigated by polarization measurements. The morphology, chemical composition and phase composition of electrodeposited Ni-Mo alloy powders were investigated using DSC, TGA, SEM, EDS and XRD analysis. EDS results showed that powder composition depends on Ni/Mo ions concentration ratio, as well as on the position where the EDS analysis was performed. As-deposited alloy powders were nanocrystalline showing no XRD peaks with undefined morphology (SEM). After recrystallization for 2 h in N2 atmosphere at 600?C the presence of NiMoO4 phase was identified in the powder electrodeposited from chloride electrolyte at the Ni/Mo ions concentration ratio 1/3, with well defined crystalline powder particles.

The Analyses of Learning Strategies in English as a Second Language: Theoretical Classification and Measurement Test

2020 ◽  
Vol 4 (2) ◽  
pp. 118-129
Author(s):  
Asti Gumartifa ◽  
◽  
Indah Windra Dwie Agustiani
Keyword(s):  
Language Learning ◽  
Learning Outcomes ◽  
Learning Strategies ◽  
Learning Process ◽  
English Learners ◽  
English Language ◽  
Point Of View ◽  
Effective Learning ◽  
The Impact

Gaining English language learning effectively has been discussed all years long. Similarly, Learners have various troubles outcomes in the learning process. Creating a joyful and comfortable situation must be considered by learners. Thus, the implementation of effective learning strategies is certainly necessary for English learners. This descriptive study has two purposes: first, to introduce the classification and characterization of learning strategies such as; memory, cognitive, metacognitive, compensation, social, and affective strategies that are used by learners in the classroom and second, it provides some questionnaires item based on Strategy of Inventory for Language Learning (SILL) version 5.0 that can be used to examine the frequency of students’ learning strategies in the learning process. The summary of this study explains and discusses the researchers’ point of view on the impact of learning outcomes by learning strategies used. Finally, utilizing appropriate learning strategies are certainly beneficial for both teachers and learners to achieve the learning target effectively.

The Algorithm of Characterization of an Action as a Jointly Committed Crime

2018 ◽  
pp. 37-44
Keyword(s):  
Criminal Code ◽  
Point Of View

The article discusses a sequence of activities to identify a crime as jointly committed. The requirements to the algorithm of such activities are formulated. Programme-based and targeted methods applied by the authors allowed detecting a range of stages of the algorithm. The first four stages aim at defining mandatory elements of a crime allowing to characterize it as a jointly committed action. The rest of the stages focus on identifying a type of criminal complicity. In the article, each stage is described. It is emphasized that in each stage there is a special objective. At the same time, all these stages, taken together, constitute a separate module of the program of criminal characterization of an action. From the authors’ point of view, algorithms are necessary not only for detection of crimes and their criminal characterization, but also for answering the question on existence of criminal complicity in each case. Also the authors give their opinions on interpretation of criminal complicity as a legal category. In particular, it is emphasized that not all of crimes merely committed with participation of two or more persons should be understood as jointly committed. It is joint participation that makes a crime jointly committed. Various forms of criminal complicity and types of co-offenders are considered in the article as well. In various crimes, criminal complicity manifests itself differently. Therefore the proposed algorithm can be applied only after identification a specific article of the Russian Criminal Code stipulating the responsibility for the crime committed.

scholarly journals Processing Effect and Characterization of Olive Oils from Spanish Wild Olive Trees (Olea europaea var. sylvestris)

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1304
Author(s):  
Francisco Espínola ◽  
Alfonso M. Vidal ◽  
Juan M. Espínola ◽  
Manuel Moya
Keyword(s):  
Phenolic Compounds ◽  
Volatile Compounds ◽  
Olive Tree ◽  
Extraction Yield ◽  
Point Of View ◽  
Human Consumption ◽  
Analytical Point ◽  
Wild Olive ◽  
Olive Trees

Wild olive trees have important potential, but, to date, the oil from wild olives has not been studied significantly, especially from an analytical point of view. In Spain, the wild olive tree is called “Acebuche” and its fruit “Acebuchina”. The objective of this work is to optimize the olive oil production process from the Acebuchina cultivar and characterize the oil, which could be marketed as healthy and functional food. A Box–Behnken experimental design with five central points was used, along with the Response Surface Methodology to obtain a mathematical experimental model. The oils from the Acebuchina cultivar meet the requirements for human consumption and have a good balance of fatty acids. In addition, the oils are rich in antioxidants and volatile compounds. The highest extraction yield, 12.0 g oil/100 g paste, was obtained at 90.0 min and the highest yield of phenolic compounds, 870.0 mg/kg, was achieved at 40.0 °C, and 90.0 min; but the maximum content of volatile compounds, 26.9 mg/kg, was obtained at 20 °C and 30.0 min. The oil yield is lower than that of commercial cultivars, but the contents of volatile and phenolic compounds is higher.

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