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 A New Method to Recycle Stainless–Steel Duplex UNS S31803 Chips

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 546 ◽  
Author(s):  
Mendonça Claudiney ◽  
Oliveira Adhimar ◽  
Sachs Daniela ◽  
Capellato Patricia ◽  
Ribeiro Vander ◽  
...  
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Mechanical Milling ◽  
Vanadium Carbide ◽  
Initial Density ◽  
High Energy ◽  
Industrial Sector ◽  
Milling Process ◽  
New Method

Due to the increased consumption of raw materials, energy, and the waste it generates, recycling has become very important and fundamental for the environment and the industrial sector. The production of duplex stainless–steel powders with the addition of vanadium carbide in the high energy mechanical milling process is a new method for recycling materials for the manufacture of components in the industrial sector. This study aims to reuse the chips from the duplex stainless–steel UNS S31803 by powder metallurgy with the addition of Vanadium carbide (VC). The mechanical milling was performed using a planetary ball mill for 50 h at a milling speed of 350 rpm and a ball-to-powder weight ratio of 20:1, and the addition of 3 wt % of VC. The material submitted to milling with an addition of carbide has a particle size of less than 140 μm. After milling, the sample went through a stress relief treatment performed at 1050 °C for 1 h and the isostatic compaction process loaded with 300 MPa. The sintered powders and material was characterized by scanning electron microscopy, X-ray diffraction, and micro-hardness tests. The milling process with an addition of 3% VC produced a particle size smaller than the initial chip size. The measurement of micrometric sizes obtained was between 26 and 132 μm. The sintered material had a measurement of porosity evaluated at 15%. The obtained density of the material was 84% compared to the initial density of the material as stainless–steel duplex UNS S31803. The value of the microhardness measurement was 232 HV. The material submitted for grinding presented the formation of a martensitic structure and after the thermal treatment, the presence of ferrite and austenite phases was observed. Thus, in conclusion, this study demonstrates the efficacy in the production of a metal-ceramic composite using a new method to recycle stainless–steel duplex UNS S31803 chips.

Effect of Milling Time on the Synthesis of In-situ Cu-25 Vol. % WC Nanocomposite by Mechanical Alloying

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Nurulhuda Bashirom ◽  
Hazni Fazliana Kassim
Keyword(s):  
Stainless Steel ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Weight Ratio ◽  
Copper Matrix ◽  
High Energy ◽  
Milling Process ◽  
Nominal Composition ◽  
Peak Broadening

This paper presents a study on the effect of milling time on the synthesis of Cu-WC nanocomposites by mechanical alloying (MA). The Cu-WC nanocomposite with a nominal composition of 25 vol.% of WC was produced in-situ via MA from elemental powders of copper (Cu), tungsten (W), and graphite (C). These powders were milled in the high-energy “Pulverisette 6” planetary ball mill according to the composition Cu-34.90 wt.% W-2.28 wt.% C. The powders were milled in the different milling times; 16 hours, 32 hours, and 48 hours at rotational speed of 600 rpm. The milling process was conducted under argon atmosphere by using a stainless steel vial and 10 mm diameter of stainless steel balls, with ball-to-powder weight ratio (BPR) 10:1. The as-milled powders were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD result indicated the formation of WC after milling for 32 hours, and the peak broadening was observed at higher milling time. From SEM observations, the particle size of Cu-25 vol.% WC composites was gradually refined with increasing milling time until the homogenous microstructure was obtained at 48 hours of milling, even though there were still some unreacted W particles existed in the matrix. Increasing milling time resulted in smaller crystallite size and higher lattice strain of Cu. The overall result demonstrates that the longer milling time can be used to achieve WC reinforced copper matrix nanocomposite.

Effect of Milling Speed on the Synthesis of In-Situ Cu-25 Vol. % WC Nanocomposite by Mechanical Alloying

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Nurulhuda Bashirom ◽  
Nurzatil Ismah Mohd Arif
Keyword(s):  
Stainless Steel ◽  
Mechanical Alloying ◽  
Weight Ratio ◽  
High Energy ◽  
Milling Process ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
The Matrix ◽  
Steel Balls

This paper presents a study on the effect of milling speed on the synthesis of Cu-WC nanocomposites by mechanical alloying (MA). The Cu-WC nanocomposite with nominal composition of 25 vol.% of WC was produced in-situ via MA from elemental powders of copper (Cu), tungsten (W), and graphite (C). These powders were milled in the high-energy “Pulverisette 6” planetary ball mill according to composition Cu-34.90 wt% W-2.28 wt% C. The powders were milled in different milling speed; 400 rpm, 500 rpm, and 600 rpm. The milling process was conducted under argon atmosphere by using a stainless steel vial and 10 mm diameter of stainless steel balls, with ball-to-powder weight ratio (BPR) 10:1. The as-milled powders were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD result showed the formation of W2C phase after milling for 400 rpm and as the speed increased, the peak was broadened. No WC phase was detected after milling. Increasing the milling speed resulted in smaller crystallite size of Cu and proven to be in nanosized. Based on SEM result, higher milling speed leads to the refinement of hard W particles in the Cu matrix. Up to the 600 rpm, the unreacted W particles still existed in the matrix showing 20 hours milling time was not sufficient to completely dissolve the W.

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.  

Preparation of La0.7Sr0.3Co0.2Fe0.8O3-δ (LSCF 7328) by Combination of Mechanochemical and Solid State Reaction

2017 ◽  
Vol 744 ◽  
pp. 399-403 ◽  
Author(s):  
Silvana Dwi Nurherdiana ◽  
Nikmatin Sholichah ◽  
Rendy Muhamad Iqbal ◽  
Mutya Sandei Sahasrikirana ◽  
Wahyu Prasetyo Utomo ◽  
...  
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Perovskite Oxide ◽  
Combination Method ◽  
Structure Evolution ◽  
Preparation Methods ◽  
Grinding Method

Structure evolution and morphology of La0.7Sr0.3Co0.8Fe0.2O3-δ (LSCF 7328) were investigated during two different preparation methods namely mechanochemical and combination of mechanochemical-solid state. The result shows that no characteristic peak of perovskite oxide was found on the diffractogram of the product of sole mechanochemical method at 600 rpm and up to 12 h of high energy milling process. On the other hand, the manual grinding method that was followed by solid state calcination produces irregular particle size. Due to the result, the combination of both methods was proposed to obtain the fine structure formation and particle size distribution. Rietveld refinement was used to investigate the lattice distortion. It was found that unit cell remains unchanged at increasing milling time. Moreover, the combination method produces regular particle size at milling time of 0.5 h. At longer milling time, the more regular particle size is formed which comes from highly energy transfer of milling.

Research of the Milling Time Influence on Ag-Cu Powder Particles Size Processed by Mechanical Alloying Route

2012 ◽  
Vol 188 ◽  
pp. 382-387 ◽  
Author(s):  
Oana Gîngu ◽  
Claudiu Nicolicescu ◽  
Gabriela Sima
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Mechanical Alloying ◽  
Size Distribution ◽  
Powder Mixture ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Future Research ◽  
Powder Particles

This research focuses on Ag-Cu powder particles processing by mechanical alloying (MA) route. The powder mixture is representative for the eutectic composition, respectively 72%wt. Ag + 28% wt. Cu. The milling process is developed in high energy ball mill Pulverisette 6, using different size for the milling balls, in wet conditions for 80 hours. One of the most important parameter studied in this research is the particle size distribution of the processed powder mixture. Thus, it changes along the milling time, from 10…75 µm at the beginning of MA process up to (60 – 80) nm at 80 h. The milling parameters will be optimized in future research depending on the particle size distribution related with thermophysical and thermodynamic properties focused on electrical and optical properties improvement.

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 Parametric optimization of NiFe2O4 nanoparticles synthesized by mechanical alloying

2014 ◽  
Vol 32 (2) ◽  
pp. 281-291 ◽  
Author(s):  
A. Hajalilou ◽  
M. Hashim ◽  
R. Ebrahimi-Kahrizsangi ◽  
H. Mohamed Kamari ◽  
S. Kanagesan
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
Robust Design ◽  
Milling Time ◽  
Rotation Speed ◽  
Weight Ratio ◽  
System Optimization ◽  
Average Particle ◽  
Nife2o4 Nanoparticles ◽  
Taguchi Robust Design

AbstractIn this study, the Taguchi robust design method is used for optimizing ball milling parameters including milling time, rotation speed and ball to powder weight ratio in the planetary ball milling of nanostructured nickel ferrite powder. In fact, the current work deals with NiFe2O4 nanoparticles mechanochemically synthesized from NiO and Fe2O3 powders. The Taguchi robust design technique of system optimization with the L9 orthogonal array is performed to verify the best experimental levels and contribution percentages (% ρ) of each parameter. Particle size measurement using SEM gives the average particle size value in the range of 59–67 nm. X-ray diffraction using Cu Kα radiation is also carried out to identify the formation of NiFe2O4 single phase. The XRD results suggest that NiFe2O4 with a crystallite size of about 12 nm is present in 30 h activated specimens. Furthermore, based on the results of the Taguchi approach the greatest effect on particle size (42.10 %) is found to be due to rotation speed followed by milling time (37.08 %) while ball to powder weight ratio exhibits the least influence.

Recycling Chips of Stainless Steel by High Energy Ball Milling

2018 ◽  
Vol 930 ◽  
pp. 454-459
Author(s):  
Claudiney de Sales Pereira Mendonça ◽  
Vander Alkmin dos Santos Ribeiro ◽  
Mateus Morais Junqueira ◽  
Daniela Sachs ◽  
Leonardo Albergaria Oliveira ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ball Milling ◽  
Weight Ratio ◽  
Steel Powder ◽  
High Energy ◽  
Milling Process ◽  
High Energy Ball Milling ◽  
Austenitic Phase ◽  
Energy Ball ◽  
Vanadium Carbides

Stainless steel components produced by powder metallurgy constitute an important and growing segment of the industry. The high energy ball milling process can be an alternative for the recycling of the stainless steel chips. A major advantage of stainless steel is its ability to be recyclable. The reuse of recyclable materials has as main objectives to minimize the environmental impacts and to rationalize the use of the energy chains. This work aims at the production of stainless steel, starting from machining chips pure, and with the addition of vanadium carbides by high energy planetary milling with ball to powder weight ratio 20:1, and mill speed of 350 rpm milled in argon atmosphere for 50h. The compaction of stainless steel samples with vanadium carbide was made in a cylindrical matrix at a pressure of 700 Mpa. The sintering process was performed in a vacuum atmosphere furnace at a temperature of 1200 ° C for 1h. Through the milling process with the addition of carbide it was possible to produce stainless steel powder with a mean particle size of 49 μm. By X-ray diffraction was observed the appearance of the ferritic, austenitic phase and the martensitic phase induced by deformation phase that remained even after the sintering. The density of the sintered material is around 77% of the melt, and the obtained porosity was low.

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