Metal-Graphite Couples Synthesized by Means of Mechanical Milling

2010 ◽  
Vol 1276 ◽  
Author(s):  
I. Estrada-Guel ◽  
C. Carreño-Gallardo ◽  
R. Pérez-Bustamante ◽  
J. M. Herrera-Ramírez ◽  
R. Martínez-Sánchez
Keyword(s):  
Mechanical Milling ◽  
Milling Time ◽  
Morphological Characteristics ◽  
High Energy ◽  
Inert Atmosphere ◽  
Milling Process ◽  
Pure Graphite ◽  
Metal Type ◽  
Crystallographic Characteristics ◽  
Metal Addition

AbstractThe aim of this work is the characterization of some graphite-metal couples prepared by mechanical milling (MM). The morphological and microstructural changes during MM of graphite processed with metallic powders of Cu, Ni and Ag (10 and 15 at. %) are studied. Milling is performed in a high-energy ball mill under an inert atmosphere during 1, 4 and 8 hours. The process is also repeated with a pure graphite sample in order to compare the role of metal type and concentration on the morphological characteristics of milled samples. The results show that increasing the concentration of metal particles accelerates the milling process as a result of faster work hardening and particle fracture. The results of X-ray diffraction analysis show that some crystallographic characteristics of the milled couples change as a function of milling time and metal addition. Also, SEM-EDS studies show an important effect of milling time on metal particle distribution in the prepared graphite couples.

DSC-TGA Hydrogen Evaluation during Mechanical Milling of AlFe Intermetallic

2013 ◽  
Vol 755 ◽  
pp. 105-110 ◽  
Author(s):  
E. García de León M. ◽  
O. Téllez-Vázquez ◽  
C. Patiño-Carachure ◽  
G. Rosas
Keyword(s):  
Mechanical Milling ◽  
Milling Time ◽  
Hydrogen Generation ◽  
Pure Aluminum ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

Fe40Al60 (at%) intermetallic alloy composition was obtained by conventional casting methods and subsequently subjected to high-energy mechanical milling under different conditions of humidity. All samples were characterized by X-ray diffraction patterns (XRD), transmission electron microcopy (TEM) and DSC-TGA thermogravimetric experiments. After the milling process, the amount of hydrogen generated was determined using thermogravimetric analysis and chemical reactions (stoichiometry). All techniques confirm the formation of bayerite phase which is attributed to the hydrogen embrittlement reaction between the intermetallic material and water to release hydrogen. It was observed that the hydrogen generation is increased as the ball milling time is increased. The quantity of hydrogen evaluated is similar to that obtained in previous reported experiments with pure aluminum and some of its alloys.

Modeling Mechanical Milling Process for Synthesis of Graphite Nanoparticles and their Characterization

2014 ◽  
Vol 922 ◽  
pp. 586-591 ◽  
Author(s):  
Himanshu Panjiar ◽  
R.P. Gakkhar ◽  
B.S.S. Daniel
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Mechanical Milling ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Graphite Nanoparticles

The synthesis of graphite nanoparticles at ambient temperature by high energy mechanical milling is modelled using ANN (Artificial Neural Network). The effect of milling time on the evolution of particle size, inclusion, microstructure and morphology were examined using XRD (X-Ray Diffraction), EDS (Energy Dispersive X-Ray Spectroscopy), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope). ANN was effectively used to predict the influence of milling time on particle size and to forecast the milling time for the formation of nanoparticles. XRD results of investigation revealed change in strain behaviour of graphite particles of different sizes when heat treated.

Evaluating the morphology and distribution uniformity of AZ91D-SiC composite powder produced from magnesium chips by mechanical milling and alloying method

2021 ◽  
pp. 095440542110406
Author(s):  
Vahid Pouyafar ◽  
Ramin Meshkabadi
Keyword(s):  
Mechanical Alloying ◽  
Mechanical Milling ◽  
Composite Powder ◽  
Milling Time ◽  
Particle Distribution ◽  
Weight Ratio ◽  
High Energy ◽  
Milling Process ◽  
Xrd Pattern ◽  
Distribution Uniformity

The AZ91D-SiC composite powder was produced from machining chips using the mechanical milling and alloying processes as an effective recycling method. The mechanical milling and alloying were conducted in a high-energy planetary ball mill. The effects of milling time and ball-to-powder weight ratio (BPR) on the morphology, distribution uniformity, and powder yield were evaluated. In the mechanical milling process, the four stages of chip milling were investigated. The optimum conditions of the milling were equal to milling for 10 h and a BPR of 25:1. The powder yield was at its maximum value and did not change much by changing the milling conditions. In the mechanical alloying, a higher BPR had a more significant effect on the uniform distribution of the particles compared to a higher milling time. The uniformity of the particle distribution is higher for 5 h alloying and a BPR of 20:1. A new peak in the XRD pattern of the composite powder obtained did not appear during the mechanical alloying process. It was observed that the amount of reinforcement phase has little effect on the particle size of the composite powder, while the particle distribution was improved by reducing it up to 40%.

scholarly journals The Structural Evolution of Al86Ni9La5 Glassy Ribbons during Milling at Room and Cryogenic Temperatures

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1956
Author(s):  
Zhicheng Yan ◽  
Yan Liu ◽  
Shaopeng Pan ◽  
Yihua Hu ◽  
Jing Pang ◽  
...  
Keyword(s):  
Milling Time ◽  
Shear Bands ◽  
Structural Evolution ◽  
High Energy ◽  
Milling Process ◽  
Cryogenic Temperatures ◽  
Dynamic Simulations ◽  
Tricapped Trigonal Prism ◽  
Medium Range ◽  
Energy Ball

Melt-spun metallic Al86Ni9La5 glassy ribbons solidified at different circumferential speeds (Sc) were subjected to high-energy ball milling at room and cryogenic temperatures. Crystallization induced by milling was found in the Al86Ni9La5 solidified at lower circumferential speed (Sc = 14.7 m/s), while the Al86Ni9La5 with Sc = 36.6 m/s kept amorphous. Besides, a trend of structural rejuvenation during milling process was observed, as the onset temperatures (Tx1, Tx2) and the crystallization enthalpies (ΔH1, ΔH2) first decreased and then increased along with the milling time. We explored the structural origin of crystallization by ab initio molecular dynamic simulations and found that the tricapped trigonal prism (TTP) Ni-centered clusters with a higher frequency in samples solidified at a lower cooling rate, which tend to link into medium-range orders (MROs), may promote crystallization by initiating the shear bands during milling. Based on the deformation mechanism and crush of metallic glasses, we presented a qualitative model to explain the structural rejuvenation during milling.

Characterization of Ni-CNTs Nanocomposites Produced by Mechanical Alloying

2013 ◽  
Vol 829 ◽  
pp. 515-519 ◽  
Author(s):  
Shaghayegh Gharegozloo ◽  
Hossein Abdizadeh ◽  
Abolghasem Ataie
Keyword(s):  
Mechanical Milling ◽  
Milling Time ◽  
High Energy ◽  
X Ray Diffraction ◽  
Metal Matrix Nanocomposites ◽  
X Ray ◽  
Milling Method ◽  
Particle Refinement ◽  
Matrix Nanocomposites

The interest in using CNTs as the reinforcement of metal matrix nanocomposites has been growing considerably due to their enhanced properties. In the present work, nickel was reinforced by carbon nanotubes (CNTs) via high energy mechanical milling method. The effects of various amounts of CNTs (5%, 10%, 20% and 30%) and different milling times (1, 5, 10 and 15 hours) were investigated. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) analysis were used for evaluation of phase composition, morphology and magnetic properties of the samples, respectively. The results showed a homogeneous dispersion of CNTs into the nickel matrix phase by mechanical milling. It was observed that the increase in the milling time, for a particular amount of CNTs, caused a decrease of mean crystallite size from 56 nm to 35 nm. The increase of CNTs amount also resulted in the powder particle refinement. VSM analysis showed that with the increase of CNTs from 0% to 30%, the magnetization of the samples decreases from 52.36 to 30.74 emu/g, and the coercivity of the nanocomposites increases from 61.45 to 114 Oe.

Improved lithium insertion/extraction properties of single-walled carbon nanotubes by high-energy ball milling

2008 ◽  
Vol 23 (9) ◽  
pp. 2458-2466 ◽  
Author(s):  
JiYong Eom ◽  
HyukSang Kwon
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Single Walled Carbon Nanotubes ◽  
High Energy ◽  
Milling Process ◽  
Extraction Properties ◽  
Energy Ball ◽  
Insertion Sites ◽  
Walled Carbon Nanotubes ◽  
Ball Milling Time

The effects of ball milling on lithium (Li) insertion/extraction properties into/from single-walled carbon nanotubes (SWNTs) were investigated. The SWNTs were synthesized on supported catalysts by thermal chemical-vapor deposition method, purified, and mechanically ball-milled by high-energy ball milling. The purified SWNTs and the ball-milled SWNTs were electrochemically inserted/extracted with Li. The structural and chemical modifications in the ball-milled SWNTs change the insertion/extraction properties of Li ions into/from the ball-milled SWNTs. The reversible capacity (Crev) increases with increase in the ball milling time, from 616 mAh/g (Li1.7C6) for the purified SWNTs to 988 mAh/g (Li2.7C6) for the ball-milled SWNTs. The undesirable irreversible capacity (Cirr) decreases continuously with increase in the ball milling time, from 1573 mAh/g (Li4.2C6) for the purified SWNTs to 845 mAh/g (Li2.3C6) for the ball-milled SWNTs. The enhancedCrevof the ball-milled SWNTs is presumably due to a continuous decrease in theCirrbecause the SWNTs develop a densely packed structure on the ball milling process. The insertion of Li ions into the ball-milled SWNTs is facilitated by various Li insertion sites formed during the ball milling process in spite of small surface area than the purified SWNTs. Lithium ions inserted into various insertion sites enhance theCrevin the ball-milled SWNTs with the large voltage hysteresis by hindrance of the extraction of Li ions from the ball-milled SWNTs. In addition, the ball-milled samples exhibit more stable cycle capacities than the purified samples during the charge/discharge cycling.

scholarly journals 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

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 cm−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. 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 cm−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.  

scholarly journals Microstructure and mechanical behavior of Al-xMg/5Al2O3 nanostructured composites

2022 ◽  
Author(s):  
Mehdi Delshad Chermahini ◽  
Ghorbanali Rafiei Chermahini ◽  
Jamal Safari
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Solid Solution Hardening ◽  
Solution Hardening ◽  
Nanostructured Composite ◽  
Powder Particles ◽  
Mg Content

Abstract The effect of Mg content and milling time were investigated on the microstructure and microhardness values of Al-xMg/5Al2O3 (x = 0, 4, 8 and 12 wt %) nanostructured composite prepared via high energy milling technique. XRD results showed an acceleration of alloying process and formation of Al (Mg) ss by enhancing percentage of Mg element. Also, by increase in Mg percentage the grain size reduction was more considerable during milling treatment. Additionally, increment of the Mg content up to 12 wt%, causes the increase in micro-strain of the samples (from 0.31 to 0.82%). Increase in Mg concentration accelerates the mechanical milling process. According to SEM results a coaxial and circular morphology with a uniform distribution of powder particles has been formed. Up to 12 wt% (for each milling time), significant increase in microhardness (215 HV) was carried out due to solid solution hardening and crystallite refinement. From 10 to 15 h, a slight increase in microhardness up to 218 HV can be observed.

scholarly journals Recycling Chips of Stainless Steel Using a Full Factorial Design

Metals ◽  
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.

scholarly journals Effect Of Different Mechanical Milling Processes On Morphology And Microstructural Changes Of Nano And Micron Al-Powders

2015 ◽  
Vol 60 (2) ◽  
pp. 1235-1239 ◽  
Author(s):  
H.-S. Kim ◽  
B. Madavali ◽  
T.-J. Eom ◽  
C.-M. Kim ◽  
J.-M. Koo ◽  
...  
Keyword(s):  
Ball Milling ◽  
Mechanical Milling ◽  
Structural Changes ◽  
Structural Evolution ◽  
High Energy ◽  
Milling Process ◽  
High Energy Ball Milling ◽  
Microstructural Changes ◽  
Al Nanoparticles ◽  
Energy Ball

Abstract In this research, effect of the various mechanical milling process on morphology and microstructural changes of nano and micron Al-powders was studied. The milling of Al-powders was performed by both high energy and low energy ball milling process. The influence of milling (pulverizing) energy on the structural changes of Al-powders was studied. Al-nanoparticles were agglomerated during the MA and its size was increased with increasing milling while micron Al-powder gets flattened shape during high energy ball milling due to severe plastic deformation. Meanwhile, structural evolution during high energy ball milling of the nano powder occurred faster than that of the micron powder. A slight shift in the position of X-ray diffraction peaks was observed in nano Al-powders but it was un-altered in macro Al-powders. The variation in lattice parameters was observed only for nano Al powders during the high energy ball milling due to lattice distortion.

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