Influence of High Energy Milling on the Airflow Sensorproperty of the NBCa Ceramic

Some materials have been applied in many surrounding conditions as sensors, electronic devices and other applications. Inexpensive and reliable temperature and flow measurement are important in many applications including, for example, environmental monitoring and control, indoor air conditioning, weather forecasting, automotive and aerospace systems. Special ceramics are an example of such materials. Neodymium-Barium-Copper is a special ceramic that has high electrical conductivity and airflow sensor characteristics. This property is influenced by high energy milling of the powder, when it is not sintered. To evaluate the influence of this type of milling it was carried out an analysis of particle size as a function of milling time. SEM images and granulometric analysis showed significant reduction of particle size with the increase of milling time. For longer times of milling the mixture of precursor powders is favored, resulting in better homogeneity of the ceramic. This is reflected in the properties of airflow sensor.

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Influence of the Oxide and Ethanol Surface Layer on Phase Transformation of Al-Based Nanocomposite Powders under High-Energy Milling

Materials ◽

10.3390/ma12081305 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1305 ◽

Cited By ~ 1

Author(s):

Dora Janovszky

Keyword(s):

Particle Size ◽

Milling Time ◽

High Energy ◽

Amorphous Structure ◽

Control Agent ◽

Dry Milling ◽

Process Control Agent ◽

Composite Powders ◽

High Energy Milling ◽

Nanocomposite Powders

Pure Al particles reinforced with amorphous-nanocrystalline Cu36Zr48Ag8Al8 particles composite powders were prepared by high-energy milling without and with ethanol. The mechanical milling procedures were compared so that in the case of dry milling the particle size increased owing to cold welding, but the crystallite size decreased below 113 nm. The amorphous phase disappeared and was not developed until 30 h of milling time. Using ethanol as a process control agent, the particle size did not increase, while the amorphous fraction increased to 15 wt.%. Ethanol decomposed to carbon dioxide, water, and ethane. Its addition was necessary to increase the amount of the amorphous structure.

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Effect of Milling Time on Microstructure of CNTs/Al5083 Composites Powder by High Energy Milling

Materials Science Forum ◽

10.4028/www.scientific.net/msf.788.608 ◽

2014 ◽

Vol 788 ◽

pp. 608-612

Author(s):

Zheng Li ◽

Xiao Lan Cai ◽

Feng Yi ◽

Ming Jun Yu ◽

Chui Hu

Keyword(s):

Particle Size ◽

Crystallite Size ◽

Composite Powder ◽

Milling Time ◽

Average Crystallite Size ◽

High Energy ◽

High Energy Milling ◽

Medium Particle ◽

Medium Particle Size ◽

Time Lead

The 2wt%CNTs/Al5083 composite powder was prepared by High Energy Milling, and the effect of the milling time on microstructure of the 2wt.%CNTs/Al5083 composite powder was investigated. The Microstructure was observed by SEM, TEM and XRD. The result showed that prolonging the milling time lead to the reduction of the Medium particle size D50. The best D50 was obtained at milling 2.5h with the particle size of 22.33μm. CNTs homogeneous embedded into the Al-matrix when the milling time was 2.5h. The average crystallite size of Al was 46.4nm after milling for 2.5h, and the average crystallite size of Al also increased as the recrystallization.

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An investigation of the effect of high-energy milling time of Ti6Al4V biomaterial on the wear performance in the simulated body fluid environment

Powder Metallurgy ◽

10.1080/00325899.2017.1335956 ◽

2017 ◽

Vol 60 (5) ◽

pp. 384-392 ◽

Cited By ~ 7

Author(s):

I. Simsek ◽

D. Ozyurek

Keyword(s):

Simulated Body Fluid ◽

Body Fluid ◽

Milling Time ◽

High Energy ◽

Wear Performance ◽

High Energy Milling ◽

Fluid Environment

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Appropriate Conditions for Preparation of Nanosized WO3 through High-Energy-Milling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.665 ◽

2011 ◽

Vol 194-196 ◽

pp. 665-668

Author(s):

Chun Huan Chen ◽

Rui Ming Ren

Keyword(s):

Grain Size ◽

Milling Time ◽

Rotation Speed ◽

Processing Parameters ◽

High Energy ◽

Charge Ratio ◽

Activation Process ◽

X Ray Diffraction ◽

High Energy Milling ◽

Transmission Electron

In order to synthesize WC-Co nanopowders through an integrated mechanical and thermal activation process, WO3-Co2O3-C nanopowders need to be obtained first. It is critical how to obtain the WO3-Co2O3-C nanopowders efficiently. The effect of processing parameters on the grain size during high-energy-milling of WO3-Co2O3-C mixed powders was studied via X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the grain size of reactants can be effectively decreased with increasing the milling time, rotation speed, and charge ratio. After a certain time milling, both WO3 and C powders achieve nano-level in grain size and mixed homogeneously. The appropriate milling parameters for fabricating nanosized WO3+C+Co2O3 powders are suggested to be 4 to 8 hours of milling time, 400 RPM of rotation speed, and 40:1 to 60:1 of charge ratio.

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High Energy Milling of WС-FeСr Cemented Carbide

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.799.136 ◽

2019 ◽

Vol 799 ◽

pp. 136-141

Author(s):

Marek Tarraste ◽

Jakob Kübarsepp ◽

Kristjan Juhani ◽

Märt Kolnes ◽

Mart Viljus

Keyword(s):

Particle Size ◽

Ball Mill ◽

Size Range ◽

High Energy ◽

Cemented Carbide ◽

Cemented Carbides ◽

Binder Phase ◽

Metal Powders ◽

Powder Mixtures ◽

High Energy Milling

During production of cemented carbides hard and brittle tungsten carbide (WC) and ductile metal powders (mainly from Fe-group) are milled together. Complete milling results in a Gaussian distribution and narrow particle size range of the milled powder which promote the homogeneity and improve the properties of sintered composites. Cobalt, conventional metal employed in cemented carbides, possesses good comminution characteristics with WC powder. However, its toxicity and fluctuating price pushes researchers to find suitable alternatives and Fe-based alloys have shown most promising results. Cemented carbides with the Fe-Cr system as metal binder phase have potential to perform better than regular WC-Co composites in corrosive and oxidative environments. The goal of this paper was to prepare uniform cemented carbides powders with relatively high fraction of stainless Fe-Cr steel. To achieve a uniform powder mixture is a challenge at high ductile steel fraction. High energy milling (HEM) is a powerful technique for achieving (ultra) fine powder mixtures with narrow powder size range. HEM was carried out in a novel high energy ball mill RETSCH Emax. Milling in tumbling ball mill, which is the most widely used method, was employed for reference. Prepared powder mixtures were characterised in terms of particle size, size distribution and shape. In addition, powder mixtures were consolidated via spark plasma sintering to evaluate the effect of the milling method and the duration on the microstructure of final cemented carbide.

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Changes in Particle Size and Crystallinity in Ground Nickel Powder

Materials Science Forum ◽

10.4028/www.scientific.net/msf.587-588.468 ◽

2008 ◽

Vol 587-588 ◽

pp. 468-472

Author(s):

J.M. González ◽

José A. Rodríguez ◽

Enrique J. Herrera

Keyword(s):

Particle Size ◽

Specific Surface ◽

Crystallite Size ◽

Surface Area ◽

Specific Surface Area ◽

Nickel Powder ◽

Milling Time ◽

High Energy ◽

Published Data ◽

Average Particle

Nickel powder was dry-milled using a high-energy disc-oscillating mill. The average particle size increases and the specific surface area diminishes with milling time. Crystallite size decreases and microstrains increase, under the same conditions, as shown by X-ray analysis. At 120 min milling time, the crystallite size has a value of 17 nm, i.e., a nanostructured powder, with a perturbed lattice, is obtained. The above results have been compared with published data about the effects of milling on a ceramic powder. There is, in both cases, a general agreement concerning the changes produced in crystallite size. Nevertheless, opposite results are reached regarding particle size and specific surface area.

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PEMANFAATAN TEKNIK HEM UNTUK PENUMBUHAN CNT DARI GRAFIT MENGGUNAKAN Ni SEBAGAI KATALIS = UTILIZATION OF HEM TECHNIQUE FOR GROWTH OF CNT FROM GRAPHITE POWDERS BY USING Ni AS CATALYST

Majalah ilmiah Pengkajian Industri ◽

10.29122/mipi.v10i1.101 ◽

2016 ◽

Vol 10 (1) ◽

pp. 35-40

Author(s):

Yunasfi . ◽

P. Purwanto ◽

Mashadi .

Keyword(s):

Particle Size ◽

Raman Spectroscopy ◽

Electron Microscope ◽

Carbon Nanotube ◽

Surface Area ◽

Transmission Electron Microscope ◽

Milling Time ◽

High Energy ◽

Milling Process ◽

Transmission Electron

Utilization of HEM (high energy milling) technique for growth of CNT (carbon nanotube) from graphite powders by using Ni as catalyst was carried out. Milling process performed on a mixture of graphite powder and nickel powder (Ni-C powders) with the ratio of weight percent of 98%: 2%, with a variation of milling time between 25 up to 75 hours. Characterization using PSA (Powder Size Analyzer), SAA (Surface Area Analyzer), TEM (Transmission Electron Microscope) and Raman Spectroscopy performed to obtain information about particle size, surface area, morphology and the structure bonding of the milled powder respectively. The analysis results of Ni-C powders using PSA and SAA showed the smallest particle size and biggest surface area obtained after milling process for 50 hours, i.e. 80 nm and 705 m2/g, respectively. TEM observations revealed formation of flat fibers which quantity increased with increasing milling time. This flattened fiber behave as an initiator for the growth of CNTs. Ni-C powder milling for 50 hours results more clearly show the growth of CNTs. Analysis by Raman Spectroscopy showed two bands at 1582 cmâˆ’1 as a peak of G band and at 1350 cm-1 as a peak of D band. These spectra are typical for sp2 structure. The position of G band peak is close to 1600 cm-1 as the evidence of a change to nano-crystalline graphite. The highest intensity of D band shown in the milling process for 50 hours, which indicates that this milling time produces more graphite-like structure compared to other conditions, and is predicted good for growing CNTs.Â AbstrakPemanfaatan teknik HEM (High Energy Milling) untuk penumbuhan CNT (carbon nanotube) dari serbuk grafit dengan menggunakan Ni sebagai katalis. Proses milling dilakukan terhadap campuran serbuk grafit dan serbuk nikel (serbuk Ni-C) dengan perbandingan berat 98% : 2%, dengan variasi waktu milling antara 25-75 jam. Karakterisasi menggunakan fasilitas PSA (Particle Size Analyzer), SAA (Surface Area Analyzer), dan TEM (Transmission Electron Microscope) serta Raman Spektroscopy yang masing-masingnya untuk mendapatkan informasi tentang ukuran partikel, luas permukaan dan morfologi serta struktur ikatan serbuk hasil milling. Hasil analisis serbuk Ni-C dengan PSA dan SAA menunjukkan ukuran partikel paling kecil dan luas permukaan paling besar diperoleh setelah proses milling selama 50 jam, masing-masing 80 nm dan 705 m2/g. Pengamatan TEM menunjukkan serbuk-serbuk berbentuk serat pipih dengan kuantitas yang meningkat dengan bertambahnya waktu milling. Serat pipih ini perupakan cikal bakal penumbuhan CNT. Serbuk Ni-C hasil milling menunjukkan penumbuhan CNT terlihat lebih jelas setelah milling selama 50 jam. Hasil analisis dengan Raman Spectroscopy memperlihatkan puncak G band pada bilangan gelombang 1582 cmâˆ’1 yang merupakan spektrum untuk struktur sp2 dari grafit dan puncak D band pada bilangan gelombang 1350 cm-1 yang mungkin merupakan deformasi struktur grafit. Posisi puncak G band mendekati 1600 cm-1 menjadi bukti perubahan ke grafit nano kristal. Intensitas D band tertinggi ditunjukkan oleh sistem komposit Ni-C hasil proses milling selama 50 jam dan hal ini sebagai indikasi bahwa proses milling selama 50 jam terhadap sistem komposit Ni-C lebih berstruktur mirip grafit (graphitic-like material) dibanding kondisi lainnya dan diprediksi bagus untuk menumbuhkan CNT. Dengan demikian, waktu milling yang optimal untuk penumbuhan CNT dari serbuk grafit dengan menggunakan Ni sebagai katalis adalah adalah 50 jam.Â Â

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Influence of High Energy Milling Time on the Ti-50Ta Biomedical Alloy Structure

Acta Physica Polonica A ◽

10.12693/aphyspola.130.1033 ◽

2016 ◽

Vol 130 (4) ◽

pp. 1033-1036 ◽

Cited By ~ 3

Author(s):

I. Matuła ◽

G. Dercz ◽

M. Zubko ◽

K. Prusik ◽

L. Pająk

Keyword(s):

Milling Time ◽

High Energy ◽

Alloy Structure ◽

High Energy Milling ◽

Biomedical Alloy

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Recycling Chips of Stainless Steel Using a Full Factorial Design

Metals ◽

10.3390/met9080842 ◽

2019 ◽

Vol 9 (8) ◽

pp. 842

Author(s):

Claudiney Mendonça ◽

Patricia Capellato ◽

Emin Bayraktar ◽

Fábio Gatamorta ◽

José Gomes ◽

...

Keyword(s):

Particle Size ◽

Stainless Steel ◽

Duplex Stainless Steel ◽

Vanadium Carbide ◽

Milling Time ◽

Rotation Speed ◽

Weight Ratio ◽

High Energy ◽

Milling Process ◽

Full Factorial

The aim of this study was to provide an experimental investigation on the novel method for recycling chips of duplex stainless steel, with the addition of vanadium carbide, in order to produce metal/carbide composites from a high-energy mechanical milling process. Powders of duplex stainless steel with the addition of vanadium carbide were prepared by high-energy mechanical ball milling utilizing a planetary ball mill. For this proposal, experiments following a full factorial design with two replicates were planned, performed, and then analyzed. The four factors investigated in this study were rotation speed, milling time, powder to ball weight ratio and carbide percentage. For each factor, the experiments were conducted into two levels so that the internal behavior among them could be statistically estimated: 250 to 350 rpm for rotation speed, 10 to 50 h for milling time, 10:1 to 22:1 for powder to ball weight ratio, and 0 to 3% carbide percentage. In order to measure and characterize particle size, we utilized the analysis of particle size and a scanning electron microscopy. The results showed with the addition of carbide in the milling process cause an average of reduction in particle size when compared with the material without carbide added. All the four factors investigated in this study presented significant influence on the milling process of duplex stainless steel chips and the reduction of particle size. The statistical analysis showed that the addition of carbide in the process is the most influential factor, followed by the milling time, rotation speed and powder to ball weight ratio. Significant interaction effects among these factors were also identified.

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