Heat Treatment of Nanostructured Powders Obtained by Spark Erosion of WC-8Co Cemented Carbide in Oil

2020 ◽  
Vol 312 ◽  
pp. 297-302
Author(s):  
M.I. Dvornik ◽  
Elena A. Mikhailenko
Keyword(s):  
Heat Treatment ◽  
Specific Energy Consumption ◽  
Average Diameter ◽  
Rapid Crystallization ◽  
Excess Carbon ◽  
Spark Erosion ◽  
Chemical And Phase Compositions ◽  
Process Productivity ◽  
Spherical Microparticles ◽  
Nanostructured Powders

Spark erosion of WC-8Co carbide pieces in oil resulted in a powder consisting of nanostructured spherical microparticles formed by rapid crystallization of the melt. These particles consist of rounded WC grains with an average diameter of about 0.18 μm, surrounded by cobalt. The process productivity, specific energy consumption, microstructure, particle size distribution, chemical and phase compositions of the obtained powder are determined. It was found that as a result of oil pyrolysis, free carbon is formed (3.4 %), which makes this powder unsuitable for the production of carbide products from it. A technique has been developed and the process of controlled removal of excess carbon by annealing the obtained powder in a CO2 atmosphere at a temperature of 1000 °C has been studied. As a result of annealing for 120 minutes, the carbon content decreases to the required value (5.6 %). Studies of the phase composition and microstructure showed that the obtained particles consist of elongated WC grains, the average diameter of which increased to 0.43 μm.

scholarly journals Product Identification Sparks Erosion of Aluminum in Aqueous Medium

2019 ◽  
Vol 5 (12) ◽  
pp. 61-68
Author(s):  
S. Usarova ◽  
A. Sativaldiev
Keyword(s):  
Heat Treatment ◽  
Comparative Analysis ◽  
Aqueous Medium ◽  
Main Product ◽  
Aluminium Oxide ◽  
Coherent Scattering ◽  
Spark Erosion ◽  
Product Identification ◽  
Alumina Particles

A comparative analysis of the methods for producing aluminium oxide nanopowders is presented and the products of electro spark erosion of aluminium in an aqueous medium are identified. Based on the data on the broadening of diffraction reflections, calculations were performed to estimate the sizes of the coherent scattering regions (CSRs) of alumina particles obtained by heat treatment of the product of electric spark dispersion of aluminium in water. In conclusion, it is concluded that the product of heat treatment of the main product of electro spark dispersion of aluminium in water is γ-Al2O3 nano dispersed aluminium oxide.

Improving in cold resistance of castings made of 20GL type steels

2021 ◽  
pp. 195-202
Author(s):  
A.F. Degtyarev ◽  
V.N. Skorobogatykh ◽  
V.V. Nazaratin ◽  
F.A. Nuraliev ◽  
A.S. Kaftannikov
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Cold Resistance ◽  
High Impact ◽  
Reliable Operation ◽  
Treatment Technology ◽  
Heat Treatment Technology ◽  
High Impact Strength ◽  
Rational Control ◽  
Chemical And Phase Compositions

The analysis of the literature data on the steels used for the manufacture of castings operating at negative temperatures and the technology of their manufacture is carried out. The effect of chemical and phase compositions on the strength and impact strength characteristics is revealed. The rational technology for manufacturing of these castings is considered. Methods for obtaining of high impact strength of castings made of 20GL type steels at –40...–60 °C temperatures are given. Modification, microalloying and rational modes of heat treatment are used as methods of rational control of the steels structure. The heat treatment technology of castings, which provides the necessary package of properties and reliable operation, is proposed.

Effect of Heat Treatment on the Mechanical Property of PAN-PEO Hybrid Nanofiber Membrane

2015 ◽  
Vol 1104 ◽  
pp. 95-99 ◽  
Author(s):  
Xu Lu ◽  
Li Ni
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Property ◽  
Polyethylene Oxide ◽  
Average Diameter ◽  
Diameter Distribution ◽  
Nanofiber Membrane ◽  
Hybrid Nanofiber ◽  
Scanning Electron

It is necessary for nanofiber membrane’s application to improve its mechanical properties. In the paper, two spinnerets were used to prepare polyacrylonitrile-polyethylene oxide (PAN-PEO) hybrid nanofiber membrane and then heat treatment was used to improve their mechanical properties.Based on the scanning electron microscopy (SEM) technology the average diameter of the hybrid nanofiber was obtained. After the heat treatment at 100°C, their diameter decrease and the diameter distribution become narrow. It is found that heat treatment can improve the mechanical properties. The nanofiber membrane got mechanical properties with broken stress 17.29 Mpa, broken strain 38.48% and initial module 86 Mpa by treating at 100°C for 1 hour.

scholarly journals Hőkezelési folyamat számítógépes modellezése

2009 ◽  
Vol 4 (1) ◽  
pp. 117-123
Author(s):  
Zoltán Fabulya ◽  
György Hampel
Keyword(s):  
Heat Treatment ◽  
Computer Simulation ◽  
Energy Consumption ◽  
Specific Energy Consumption ◽  
Time Span ◽  
Fuel Gas ◽  
Environment Management ◽  
Treatment Processes ◽  
Long Time ◽  
Canned Meat

The heat treatment of cans, particularly canned meat, is a process with a big energy need, since the cans need sterilization, a heat treatment with a long time span around 120°C with the use of fuel gas in big quantity. The reduction of the use of the natural resources is the challenge in our days which appears in the new system approach of the environment management, the principle of sustainable development. That is to say, let us produce the same amount of products with less energy consumption, or more amounts with less specific energy consumption. The heat treatment is used to avert microbiological danger. The operation regulation has to be defined in a way which produces a microbiologically reliable product, but does not harm its organoleptic peculiarities, substance, taste and flavour because of the oversized treatment. In the interest of safety we have to define the extent and the time span of the heat effect leading to the destruction of the microbiological pathogens with the use of engineering calculations, modelling and computer simulation. We also have to secure the observance of the regulations obtained this way for the sake of the higher quality and the less resource utilization. This observance ability is answered with the help of our developed model for the computer simulation of heat treatment processes.

Experimental Study on Heat Treatment of SS 420 and EN 24 Using Nanoparticulate Quenching Process

2018 ◽  
Vol 18 (06) ◽  
pp. 1850040
Author(s):  
N. Manikanda Prabu ◽  
G. Sureshkannan ◽  
P. Maniiarasan ◽  
V. S. Thangarasu
Keyword(s):  
Heat Transfer ◽  
Heat Treatment ◽  
Current Trend ◽  
Average Diameter ◽  
Tempering Temperature ◽  
Quenching Effect ◽  
Quenching Medium ◽  
Research Areas ◽  
Heat Treated ◽  
Quenching Time

Heat transfer through nanotechnology is a current trend which occupies most research areas with improved results. Taking this concept, the present work has been focused on the analysis of quenching effect on steel such as EN 24 and SS 420 with nanoparticles dispersed in quenching medium. Quenching is the process of removing heat from the heat-treated elements which also take part in determining the hardness values depending on the heat transfer rate and quenching time. To ensure the outcome properties, different volume concentrations of nanofluids have been prepared by adding TiO2 nanoparticles with the average diameter of less than 20[Formula: see text]nm in synthetic oil. Here, it is planned to have four volume concentrations (0.25[Formula: see text]g/lit, 0.375[Formula: see text]g/lit, 0.5[Formula: see text]g/lit, 0.625[Formula: see text]g/lit) of nanofluids to be used in the experiment. The materials after facing heat treatment up to 850∘C (EN 24) and 980∘C (SS 420), are subjected to quenching by using nanofluid. The work has been carried out by altering the tempering temperature and volume of nanoparticles in the quenching medium. The outcome quality of the product desirably supports our expectations, such as improved hardness and reduced time consumption for quenching. Additionally, the comparative analysis shows an improvement in heat transfer characteristics as well as properties in quenched specimen with nanofluids.

scholarly journals Post-electrospinning crosslinking of guar/polyvinyl alcohol membrane

2016 ◽  
Vol 20 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Jingjing Shi ◽  
Enlong Yang
Keyword(s):  
Heat Treatment ◽  
Citric Acid ◽  
Polyvinyl Alcohol ◽  
Guar Gum ◽  
Weight Ratio ◽  
Average Diameter ◽  
Alcohol Solution ◽  
Electrospun Nanofiber ◽  
Ft Ir ◽  
Nanofiber Membranes

College of Material and Textile Engineering, Jiaxing University, Jiaxing, China The present study reports post-electrospinning crosslinking of guar/polyvinyl alcohol (PVA)/citric acid nanofiber membranes by heat treatment. Porous, interconnected nonwoven nanofiber membranes (average diameter 194?23 nm) were electrospun from a homogeneous blend of 1wt% guar gum and 8wt% polyvinyl alcohol solution (3:7 weight ratio) containing 5 wt% (by the total weight of the solution) citric acid. The electrospun nanofiber membranes were then cured at 140 oC for 2 h. The crosslinked nanofiber membranes were insoluble in water, while the non-crosslinked membranes dissolved instantaneously. FT-IR spectrum investigates that crosslinking of guar/PVA occurred through esterfication reaction during heat treatment.

Tuning Surface Plasmon in Erbium-Boro-Tellurite Nanoglass via Thermal Annealing

2016 ◽  
Vol 846 ◽  
pp. 85-90
Author(s):  
Zahra Ashur Mahraz ◽  
M.R. Sahar ◽  
S.K. Ghoshal
Keyword(s):  
Heat Treatment ◽  
Surface Plasmon ◽  
Average Diameter ◽  
Ir Absorption ◽  
Ag Nps ◽  
Absorption Bands ◽  
Time Duration ◽  
Maximum Enhancement ◽  
Silver Nps ◽  
Quenching Method

The demand for tunable surface plasmon (SP) of embedded metal nanoparticles (NPs) in rare earth doped inorganic lasing glasses is ever-growing. Following melt quenching method Er3+ doped zinc-boro-tellurite glasses containing silver (Ag) NPs are prepared. Glasses are heat treated (thermally annealed) at varying temperatures and time duration to alter the NPs morphology which generates SP. The annealing assisted SP resonance mediated modification in spectral features is discerned. Samples heat treatment at 410 °C for 6 hrs duration ensures the reduction of Ag+ ions to Ago NPs. Thermally annealed glasses are characterized via XRD, UV–Vis-IR absorption, photoluminescence spectroscopy, and TEM imaging. XRD spectra confirm the amorphous nature of the glass and TEM image reveals the existence of homogeneously distributed spherically shaped silver NPs of average diameter ~4.5 nm. NPs are found to grow with the increase of both annealing time and temperature. The UV–Vis spectra exhibit seven absorption bands corresponding to 4f–4f transitions of Er3+ ions in the wavelength range of 500-650 nm. The localized SPR band is evidenced at 550 and 580 nm. Heat treatment causes a red shift of the plasmon peaks ascribed to the alteration in glass refractive index. Furthermore, the glass sample annealed for 6 hrs displays maximum enhancement in the emission intensity corresponding to the peaks centered at 536 (2H11/2→4I15/2), 550 (4S3/2→4I15/2) and 632 nm (4F9/2→4I15/2). This enhancement is primarily attributed to the local field effect of the silver NPs. Admirable features of the results suggest that our systematic method for heat treatment in tuning NPs size assisted SPR may contribute towards the development of functional glass.

scholarly journals Removal of mineral oil during recovered paper processing

TAPPI Journal ◽  
2016 ◽  
Vol 15 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Christian Ewald ◽  
Antje Kersten ◽  
Samuel Schabel
Keyword(s):  
Heat Treatment ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Mineral Oil ◽  
Oil Removal ◽  
Chemical Concentration ◽  
Flotation Process ◽  
Inorganic Particles ◽  
Mineral Oils ◽  
Treatment Processes

A flotation process and two different heat treatment processes prior to pulping were investigated according to their ability to remove mineral oils. For flotation, a correlation between removal of mineral oils and inorganic particles could be found for all process chemicals used in this study. By optimization of chemical concentration and dosing sequence, up to 80% of mineral oils could be removed while keeping the total losses smaller than 15%. The heat treatment processes achieved mineral oil removal rates that were in some cases even higher than those for flotation. For these processes, the most important parameters appeared to be the specific energy applied, the temperature, and the particle size distribution of recovered paper components. However, the specific energy consumption was quite high.

scholarly journals Design and fabrication of a modified fish feed pelletizing machine

2021 ◽  
Vol 7 (2) ◽  
pp. 01-011
Author(s):  
Orua Okon Antia ◽  
Ubong Edet Assian ◽  
Youngson N. Ukaru
Keyword(s):  
Power Transmission ◽  
Average Length ◽  
Operation Mode ◽  
Specific Energy Consumption ◽  
Average Diameter ◽  
Screw Conveyor ◽  
Small Scale ◽  
Fish Feed ◽  
Lower Efficiency ◽  
Mean Values

Fish feed pelletizing machine was designed and fabricated with the aim to improve on existing local pelletizers; encourage local technology and local fish farmers who may be faced with no power supply. It mainly consists of the hopper, pelletizing chamber, frame, bolts and nuts, screw conveyor, cutting mechanism, pelletizing die plate and power transmission unit with dual operation mode. Performance evaluations of the improved pelletizing machine as well as existing machine were carried out and the results showed that both machines were able to produce pellets with 8 mm average diameter and 10 mm average length. The overall mean values of pelleting capacity, specific energy consumption and efficiency of improved and the existing pelletizing machines were 1.20 kg/min, 0.010 kWh/kg and 97.09%; 0.89 kg/min, 0.014 kWh/kg and 75%, respectively. These imply that the improved pelletizing machine could produce a ton of feeds for a 14-hour daily operation and consume approximately 10 kWh of energy as compared to the existing pelletizing machine that would consume 14 kWh. The capacity of the improved pelletizing machine is quite better than the existing pelletizing machine. The improved pelletizing machine efficiency obtained is quite impressive as only about 2.91% of the feed mix might be lost as compared to 25% lost by the existing pelletizing machine. Therefore, the improved fish feed pelletizing machine is recommended for use by small-scale fish feed mill as the existing pelletizers have comparable higher losses couple with lower efficiency.

Potential Spark Erosion Approaches to Silicon Nanoparticles Production

2014 ◽  
Vol 936 ◽  
pp. 1764-1768
Author(s):  
Ahmad Farooq ◽  
Wei Wang
Keyword(s):  
Silicon Nanoparticles ◽  
Preparation Method ◽  
Research Work ◽  
Average Diameter ◽  
Wire Edm ◽  
Boron Doped ◽  
Spark Erosion ◽  
Doped Silicon ◽  
Machining System ◽  
Novel Method

This article demonstrates potential approaches to the production of Silicon Nanoparticles (SiNPs) using spark erosion in forms of Wire-EDM (WEDM), Die-sink and Micro -EDM. Utilizing the data from research work on such conventional spark erosion approaches, a novel method of nanoparticle production called high pressure flushing spark erosion has been introduced in this paper. This is an automated prototype machining system that utilizes deionized water sprayed @ 0.8 MPa through a rotating copper tool, boring on boron doped silicon ingot workpiece. SiNPs comprising an average diameter of 50nm were generated with approximate productivity of 1.5g/hr. The results demonstrate that the process holds excellent potential as an industrialized SiNPs preparation method in terms of size and productivity.

Sign in / Sign up

Export Citation Format

Share Document