The Synthesis of In Situ Cu-NbC-VC Nanocomposites by Mechanical Alloying

2014 ◽  
Vol 695 ◽  
pp. 151-154
Author(s):  
Wan Mohd Hilmi Hussein Wan Omar ◽  
Nurulhuda Bashirom ◽  
Zuhailawati Hussain ◽  
Indra Putra Almanar ◽  
Wan Abdul Rahman Assyahid Wan Ibrahim
Keyword(s):  
Mechanical Alloying ◽  
Microwave Sintering ◽  
Niobium Carbide ◽  
Milled Powder ◽  
Average Crystallite Size ◽  
Graphite Powder ◽  
Xrd Analysis ◽  
Phase Identification ◽  
Stoichiometric Ratio ◽  
Mechanically Alloyed

This paper presents a study on the synthesis of Niobium Carbide (NbC) and Vanadium Carbide (VC) in Copper (Cu) matrix by mechanical alloying (MA) technique. The elemental powders of Cu, Niobium (Nb), Vanadium (V) and synthetic graphite powder were mechanically alloyed for 30 hours at 400 rpm in a planetary ball mill Fritcsh “Pulverisette 6” according to the stoichiometric ratio of Cu-(10-x) vol%NbC-(0+x) vol%VC (x=1,3,5,7,9). The milling was performed under Argon atmosphere. The as-milled powder were compacted at 400 MPa and sintered using a microwave sintering furnace at 900°C with 1 hour soaking time. The phase identification was performed by using the X-ray Diffraction (XRD) analysis on the as-milled powders and sintered pellets. From the result, the NbC and VC phases were successfully formed after milling, and were precipitated after sintering. The average crystallite size and lattice strain of Cu, before and after sintering were 42.302 nm, 0.013%, and 71.294 nm, 0.004%, respectively.

Characterization of In Situ Cu-NbC-VC Nanocomposite by Mechanical Alloying and Microwave Sintering

2014 ◽  
Vol 695 ◽  
pp. 344-347
Author(s):  
Wan Mohd Hilmi Hussein Wan Omar ◽  
Nurulhuda Bashirom ◽  
Zuhailawati Hussain ◽  
Indra Putra Almanar ◽  
Wan Abdul Rahman Assyahid Wan Ibrahim
Keyword(s):  
Electrical Conductivity ◽  
Mechanical Alloying ◽  
Microwave Sintering ◽  
Niobium Carbide ◽  
Milled Powder ◽  
Graphite Powder ◽  
Xrd Analysis ◽  
Phase Identification ◽  
Stoichiometric Ratio

This paper presents a study on the characterization of physical and electrical properties of Niobium Carbide (NbC) and Vanadium Carbide (VC) in Copper (Cu) matrix by mechanical alloying (MA) technique. The elemental powders of Cu, Niobium (Nb), Vanadium (V) and synthetic graphite powder were mechanically alloyed for 30 hours at 400 rpm in a planetary ball mill according to the stoichiometric ratio of Cu-(10-x) vol%NbC-(0+x) vol%VC (x=0,1,3,5,7,9) under Argon atmosphere. The as-milled powder were compacted at 400 MPa and sintered using microwave sintering furnace at 900°C with 1 hour soaking time. The phase identification was made by using the X-ray Diffraction (XRD) analysis. The microhardness, relative density and apparent porosity of sintered pellets were measured using Vickers microhardness and Archimedes principle, respectively. Electrical conductivity was measured using 2 point probe technique. Density of composite increase with increasing NbC content, while electrical conductivity also increase when NbC was added. Microhardness showed that single phase carbide has higher hardness value then multicarbide.

Preparation of Dispersion-Strengthened Coppers with Niobium Carbide and Niobium Boride by Mechanical Alloying

2006 ◽  
Vol 514-516 ◽  
pp. 707-711 ◽  
Author(s):  
Vanessa Livramento ◽  
M.T. Marques ◽  
Jose Brito Correia ◽  
Amélia Almeida ◽  
Rui Vilar
Keyword(s):  
Mechanical Alloying ◽  
Niobium Carbide ◽  
Graphite Powder ◽  
Copper Matrix ◽  
Nominal Composition ◽  
Transition Elements ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
Crystalline Boron

The present study examines nanocomposites prepared by mechanical alloying of copper with other transition elements, which will produce a dispersion of stable boride and carbides reinforcement particles within a nanostructured copper matrix, at room temperature. Copper, niobium, boron and graphite powder mixtures were mechanically alloyed for several hours in a planetary ball-mill, in argon atmosphere and using a stainless steel container. The powder mixtures were produced with nominal composition of 10-30 vol.% NbC and 7-10 vol.% NbB2, using powders of pure elemental Cu, Nb, synthetic graphite and crystalline boron. The microstructural changes during milling of these powder mixtures were studied using X-ray diffraction, optical microscopy, scanning electron microscopy and microhardness measurements.

Characterization of Binary Mg-Mn Alloy Synthesized through Mechanical Alloying: Effects of Milling Speed

2015 ◽  
Vol 1087 ◽  
pp. 479-483 ◽  
Author(s):  
Emee Marina Salleh ◽  
Sivakumar Ramakrishan ◽  
Zuhailawati Hussain
Keyword(s):  
Mechanical Alloying ◽  
Milled Powder ◽  
High Energy ◽  
Milling Process ◽  
Planetary Mill ◽  
Argon Atmosphere ◽  
Solid Solution Phase ◽  
Mechanically Alloyed ◽  
Bulk Properties ◽  
Solid State Route

In this work, the effect of the milling speed on the properties of biodegradable Mg-1Mn alloy prepared by mechanical alloying was investigated. The magnesium-based alloy was prepared in solid state route using a high energy planetary mill. A mixture of pure magnesium and manganese powder was mechanically alloyed for 5 hours in argon atmosphere. Milling process was performed at various rotational speeds in order to investigate milling speed effect (i.e., 100, 200, 300 and 400 rpm) on phase formation and bulk properties. The as-milled powder was uniaxially compacted by cold pressing under 400 MPa at room temperature and sintered in argon atmosphere at 500 °C for an hour. X-ray diffraction analysis indicated that a single α-Mg phase was formed in magnesium matrix after sintering process. An increase in milling speed up to 300 rpm resulted in an increase in density and hardness of the binary alloy. The changes of bulk properties of the Mg-Mn alloys were correlated to the formation of solid solution phase and a reduction of porosity which led to an increasing in densification.

scholarly journals New Method of Fabrication of Fe80Cr20 Alloy: Effect of its Technique on Crystallite Size and Thermal Stability

2020 ◽  
Vol 1 (1) ◽  
pp. 26-31
Author(s):  
Dafit Feriyanto ◽  
Supaat Zakaria
Keyword(s):  
Thermal Stability ◽  
Mechanical Alloying ◽  
Crystallite Size ◽  
Combination Treatment ◽  
Alloy Powder ◽  
Xrd Analysis ◽  
New Method ◽  
Ultrasonic Technique ◽  
Mechanically Alloyed ◽  
Thermal Stability Of

This paper focuses on the effect of the new method on the crystallite size and thermal stability of Fe80Cr20 alloy powder. Generally, the ball milling sample and ultrasonic technique sample have dissatisfaction result when applied at high temperature. In addition, the combination of both techniques not yet carried out. Therefore, this study aim to investigate an appropriate technique to produce smallest crystallite size in order to improve the thermal stability. The new method of mechanical alloying (mill) and ultrasonic technique (UT) were applied in order to reduce the crystallite size and improve thermal stability. The new method is called as combination treatment. This condition allows the enhancement of thermal stability of Fe80Cr20 alloy powder. In this study, mechanical alloying process was carried out by milling time of 60 hours. Then, the ultrasonic technique was performed at frequency of 35 kHz at 3, 3.5, 4, 4.5, and 5 hours. From XRD analysis, it was found that the broader peaks indicated the smaller crystallite size. It shows that the combination treatment (milled and UT) reduce the crystallite size up to 2.171 nm when mechanically alloyed for 60 hours (milled 60 h) and followed by ultrasonic treatment for 4.5 hours (UT 4.5 h). Smallest crystallite size enhance the thermal stability up to 12.7 mg which shown by TGA analysis during 1100 0C temperature operation. The combination treatment is method which is effective to fabricate Fe80Cr20 alloy powder.

Investigation the Structural and Magnetic Properties of FINEMET Type Alloy Produced by Mechanical Alloying

2014 ◽  
Vol 970 ◽  
pp. 252-255 ◽  
Author(s):  
Tayebeh Gheiratmand ◽  
Saeed Mohammadi Siyani ◽  
Hamid Reza Madaah Hosseini ◽  
Parviz Davami
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Mechanical Alloying ◽  
Milled Powder ◽  
Main Peak ◽  
X Ray Diffraction ◽  
Type Alloy ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron

In this research, FINEMET alloy with composition of Fe73.5Si13.5B9Nb3Cu1was produced by mechanical alloying from elemental powders. The effect of milling time on the magnetic and structural properties of alloy has been investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometery. The results showed that milling for 53 hr leads to the formation of Fe supersaturated solid solution which includes Si, B and Nb atoms with mean crystallite size of ~30 nm. The shift of the main peak of Fe to the higher angles indicated that Si and B atoms dissolve in the Fe solid solution, at primary stage of mechanical alloying, up to the 42 hr while Nb atoms dissolve at final stages. The magnetization of milled powder for 53 hr was 173.7 emu/g, almost the same as that of the melt-spun ribbon. In addition; the coercivity reached to 15.5 Oe after 53 hr of milling. The higher value of coercivity in mechanically alloyed samples is attributed to strains induce to the structure during milling and the lack of amorphous phase and exchange interaction between nanograins.

Nanostructured Hydroxyapatite by Microwave Sintering

2008 ◽  
Vol 8 (2) ◽  
pp. 944-948 ◽  
Author(s):  
Dong Seok Seo ◽  
Kyu Hong Hwang ◽  
Jong Kook Lee
Keyword(s):  
Grain Size ◽  
Microwave Sintering ◽  
Milled Powder ◽  
Xrd Analysis ◽  
Molar Ratio ◽  
Sintering Process ◽  
Dense Microstructure ◽  
Uniform Microstructure ◽  
Nanocrystalline Particles ◽  
Conventional Sintering

In this work, nanostructured HA ceramics with dense microstructure were prepared by microwave sintering process and their microstructures were compared with the case of conventional sintering. Commercially obtained HA powder with Ca/P molar ratio of 1.67 was used as a starting material. The powder of granular type consists of nanocrystalline particles of 20–30 nm in size. The as-received HA powder or the powder calcined at 800 °C, followed by ball-milling was used for the preparation of HA disks. Microwave sintering was conducted at 1200 °C for 5 min with a heating rate of 50 °C/min. HA ceramics with the sintered densities of approximately 96–97% of the theoretical were obtained. XRD analysis showed that all detectable peaks are identical to pure hydroxyapatite. The HA sintered body made of calcined and ball-milled powder showed uniform microstructure with grain size of 300–400 nm and with finer sub-grains of 30–40 nm.

Characterization of Tantalum Carbide Reinforced Copper Composite Developed Using Mechanical Alloying

2011 ◽  
Vol 471-472 ◽  
pp. 798-803 ◽  
Author(s):  
Emee Marina Salleh ◽  
Zuhailawati Hussain
Keyword(s):  
Milled Powder ◽  
Graphite Powder ◽  
Copper Matrix ◽  
High Energy ◽  
Planetary Mill ◽  
Tantalum Carbide ◽  
Mechanically Alloyed ◽  
Consolidation Pressure ◽  
Copper Composite

The effects of the consolidation pressure on the properties of novel Cu-15vol% TaC composite was investigated. The copper-based composite has been prepared using a high energy planetary mill via in-situ route. A mixture of copper, tantalum and graphite powder was mechanically alloyed for milling time of 8 hours at speed of 400 rpm. The as-milled powder was consolidated by cold pressing under various pressure (i.e. 100, 200, 300 and 400 MPa) at room temperature and sintered in argon atmosphere at 900 °C for an hour. TaC phase was formed in copper matrix after sintering process. An increase in consolidation pressure resulted in an increase in hardness, electrical conductivity and density of the composites. The changes of bulk properties of the in-situ Cu-TaC composite were correlated to the formation of TaC phase and a reduction of porosity which led to an increasing in densification.

Chemical Redistribution and Microstructural Evolution of ODS Fe-Cr Powders During Mechanical Alloying

2018 ◽  
Vol 69 (2) ◽  
pp. 495-498
Author(s):  
Madalina Stanciulescu ◽  
Marioara Abrudeanu ◽  
Catalin Ducu ◽  
Adriana Gabriela Plaiasu
Keyword(s):  
Mechanical Alloying ◽  
Oxide Dispersion Strengthened ◽  
Xrd Analysis ◽  
Alloy Formation ◽  
Oxide Dispersion ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Solid Solution Formation ◽  
X Ray ◽  
Solution Formation

The oxide dispersion strengthened ferritic steel powders with chemical composition of Fe-14Cr-3W-0.3Y2O3 were mechanically alloyed from elemental powders in a planetary ball mill. Microstructural and chemical changes at different milling times were investigated by electron microscopy (SEM-EDS) and X-ray diffraction analysis (XRD). It was observed that morphology and structure of powders have experienced many stages during milling, and a quantitative mechanism was proposed. The initiation and evolution of the alloy formation started somewhere around 32 h of mechanical alloying (MA). According to microscopy and XRD analysis, in the first MA stages, milling chiefly has resulted in severe plastic deformation and grain refinement of powders, while in the later stages, alloying was progressed. It seems that 32 hours of milling are necessary to initiate the alloying process of Fe with Cr, but 78 h are not sufficient for completely dissolving W into �-Fe matrix retarding the Fe-Cr-W solid solution formation.

Structural Characterization of Mechanically Alloyed AlMg-CeO2 Composite

2015 ◽  
Vol 641 ◽  
pp. 10-16
Author(s):  
Tomasz Skrzekut ◽  
Anna Kula ◽  
Ludwik Blaz ◽  
Grzegorz Wloch ◽  
Makoto Sugamata
Keyword(s):  
Thermal Analysis ◽  
Mechanical Alloying ◽  
Structural Characterization ◽  
Hot Extrusion ◽  
Xrd Analysis ◽  
Structural Features ◽  
Structural Components ◽  
Mechanically Alloyed ◽  
Extrusion Method

A mechanical alloying and hot extrusion method was used to manufacture an AlMg-based composite reinforced by ~9 wt.% addition of CeO2. Structural features of as-extruded and re-melted samples were characterized by SEM/TEM observations and XRD analysis. Highly refined structure with uniform distribution of structural components has been received. It was found that during mechanical alloying and following hot pressing and extrusion of the material the decomposition of CeO2 oxides has been initiated. As result, formation of intermetallic grains of Al4Ce type was observed. Thermal analysis experiments combined with structural characterization allowed to determine the equilibrium state of the AlMg-CeO2 composite structure.

Microstructure of mechanically alloyed and hot-pressed Al5CuZr2

1990 ◽  
Vol 48 (4) ◽  
pp. 970-971
Author(s):  
T. E. Mitchell ◽  
P. B. Desch ◽  
R. B. Schwarz
Keyword(s):  
Mechanical Alloying ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Rapid Quenching ◽  
Hardened Steel ◽  
Alloyed Powder ◽  
Ion Milling ◽  
Mechanical Grinding ◽  
Mechanically Alloyed ◽  
Steel Container

Al3Zr has the highest melting temperature (1580°C) among the tri-aluminide intermetal1ics. When prepared by casting, Al3Zr forms in the tetragonal DO23 structure but by rapid quenching or by mechanical alloying (MA) it can also be prepared in the metastable cubic L12 structure. The L12 structure can be stabilized to at least 1300°C by the addition of copper and other elements. We report a TEM study of the microstructure of bulk Al5CuZr2 prepared by hot pressing mechanically alloyed powder.MA was performed in a Spex 800 mixer using a hardened steel container and balls and adding hexane as a surfactant. Between 1.4 and 2.4 wt.% of the hexane decomposed during MA and was incorporated into the alloy. The mechanically alloyed powders were degassed in vacuum at 900°C. They were compacted in a ram press at 900°C into fully dense samples having Vickers hardness of 1025. TEM specimens were prepared by mechanical grinding followed by ion milling at 120 K. TEM was performed on a Philips CM30 at 300kV.

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