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

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.

2015 ◽  
Vol 1087 ◽  
pp. 479-483 ◽  
Author(s):  
Emee Marina Salleh ◽  
Sivakumar Ramakrishan ◽  
Zuhailawati Hussain

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.


2011 ◽  
Vol 493-494 ◽  
pp. 219-224
Author(s):  
Nicola Döbelin ◽  
Laëtitia Galea ◽  
Urs Eggenberger ◽  
José M.F. Ferreira ◽  
Marc Bohner

Phase-pure α-TCP powder was milled using a high-energy planetary mill to obtain a partially X-ray amorphous material. Calcination at temperatures between 350 and 600 °C was employed to recrystallize the powder. The phase composition as a function of calcination time and temperature was determinedin-situusing high-temperature XRD equipment. It was found that the amorphous fraction recrystallized mainly to α-TCP, with only small amounts of β-TCP formed. At low temperatures (≤ 450 °C), a stable composition with approximately 85 wt-% α-TCP was found once 100% crystallinity was reached. The time required to reach full crystallinity depended on the calcination temperature. For temperatures > 450 °C a slow transformation to β-TCP was observed. The transformation rate depended on the calcination temperature and on the milling intensity. A moderately milled powder recrystallized to α-TCP, followed by a slow transformation to β-TCP at 600 °C, whereas an intensely milled powder also recrystallized to α-TCP, followed by a fast transformation to β-TCP at the same temperature.


2013 ◽  
Vol 829 ◽  
pp. 572-576 ◽  
Author(s):  
G. Ali Bagheri ◽  
Parvin Abachi ◽  
Kazem Purazrang ◽  
Abbas Rostami

In this study, Cu-TiC nanocomposites were produced by high energy ball milling of elemental powders and in-situ formation of TiC in the copper matrix. Cu-40wt% Ti powder mixture were milled for 60 h, then graphite powder was added, subsequently milling was continued for further 10 h. Based on theoretical calculations, at this composite, the amount of TiC as reinforcement should be 60.25vol% (45.47wt%). The effect of milling time on solution progress of titanium in the copper lattice was studied by X-Ray diffraction analysis (XRD) with CuKα radiation. Considering XRD of Cu-40wt%TiC after 60 h milling data and Williamson-Hall relation, crystallite size and lattice strain of copper were determined 12nm and 1.04% respectively. To ensure the formation of titanium carbide, XRD analysis was performed after pressing at 300MPa and sintering at 900oC for an hour and heating rate of 2.5oC/min. XRD pattern was indicated the formation of TiC,CuTi3and TiO2phases in Cu matrix.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1225
Author(s):  
Cristina García-Garrido ◽  
Ranier Sepúlveda Sepúlveda Ferrer ◽  
Christopher Salvo ◽  
Lucía García-Domínguez ◽  
Luis Pérez-Pozo ◽  
...  

In this work, a blend of Ti, Nb, and Mn powders, with a nominal composition of 15 wt.% of Mn, and balanced Ti and Nb wt.%, was selected to be mechanically alloyed by the following two alternative high-energy milling devices: a vibratory 8000D mixer/mill® and a PM400 Retsch® planetary ball mill. Two ball-to-powder ratio (BPR) conditions (10:1 and 20:1) were applied, to study the evolution of the synthesized phases under each of the two mechanical alloying conditions. The main findings observed include the following: (1) the sequence conversion evolved from raw elements to a transitory bcc-TiNbMn alloy, and subsequently to an fcc-TiNb15Mn alloy, independent of the milling conditions; (2) the total full conversion to the fcc-TiNb15Mn alloy was only reached by the planetary mill at a minimum of 12 h of milling time, for either of the BPR employed; (3) the planetary mill produced a non-negligible Fe contamination from the milling media, when the highest BPR and milling time were applied; and (4) the final fcc-TiNb15Mn alloy synthesized presents a nanocrystalline nature and a partial degree of amorphization.


2014 ◽  
Vol 1024 ◽  
pp. 239-242
Author(s):  
Zuhailawati Hussain ◽  
Emee Marina Salleh ◽  
Tran Bao Trung ◽  
Zainal Arifin Ahmad

In this study, WC-stainless steel AISI 347 hardmetal system was produced to replace WC-Co hardmetal which uses the expensive, toxic and depleted resource Co. WC, stainless steel AISI 347 and graphite powder mixture were milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Carbon was added in amounts ranging from 0 wt% until 4 wt% into the composition to avoid unwanted η (Fe3W3C) phase. As-milled powder was compacted at 300 MPa and sintered in a tube furnace at 1350°C. ɳ phase was detected in compositions with 0 and 1 wt% C addition. For 2 wt% C addition, no η (Fe3W3C) phase formation was identified. However, the η phase was detected for compositions containing 3 and 4 wt% C. Maximum hardness was achieved due to the absence of η phase.


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

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.


2007 ◽  
Vol 72 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Viseslava Rajkovic ◽  
Dusan Bozic ◽  
Aleksandar Devecerski

The microstructural and morphological changes of inert gas atomized pre-alloyed Cu-1 wt.% Al powders subjected to hith-energy milling were studied. The microhardness of hot-pressed compacts was measured as a function of milling time. The thermal stability during exposure at 800 ?C and the electrical conductivity of compacts were also examined. During the high-energy milling, severe deformation led to refinement of the powder particle grain size (from 550 nm to about 55 nm) and a decrease in the lattice parameter (0.10 %), indicating precipitation of aluminium from the copper matrix. The microhardness of compacts obtained from 5 h-milled powders was 2160 MPa. After exposure at 800?C for 5 h, these compacts still exhibited a high microhardness value (1325 MPa), indicating good thermal stability. The increase of microhardness and good thermal stability is attributed to the small grain size (270 and 390 nm before and after high temperature exposure, respectively). The room temperature electrical conductivity of compacts processed from 5 h-milled powder was 79% IACS. .


2006 ◽  
Vol 510-511 ◽  
pp. 346-349 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Khoa Xuan Huynh ◽  
Thuy Dang Nguyen ◽  
Pyuck Pa Choi ◽  
Myung-Gyu Chang ◽  
...  

Cu-TiB2 nanocomposite powders were in situ synthesized by combining high-energy ball milling of Cu-Ti-B elemental powder mixtures as precursors and subsequent self-propagating high temperature synthesis (SHS). Cu-40wt.% TiB2 was produced after SHS reaction and then diluted by copper to obtain desired homogeneous composites with 2.5, 5 and 10wt.%TiB2. Spark plasma sintering (SPS) was used to inhibit grain growth and thereby obtain fully Cu-TiB2 sintered bodies with nanocomposite structure. After SHS reaction, only Cu and TiB2 phases were detected in the SHS-product. Spheroidal TiB2 particles smaller than 250nm were formed in the copper matrix after SHS-reaction. Mechanical and electrical properties were investigated after SPS at 650°C for 30min under 50MPa. The electrical conductivity decreased from 75 to 54% IACS with increasing of TiB2 contents from 2.5 to 10wt.%. However, hardness increased from 56 to 97HRB. In addition, the tensile strength increased with increasing the TiB2 content.


2014 ◽  
Vol 592-594 ◽  
pp. 963-967
Author(s):  
Pravir Polly ◽  
K. Chandra Sekhar ◽  
Balasubramanian Ravisankar ◽  
S. Kumaran

In the present work, Al-5083-5wt% nanoyttria powders were milled for 10, 20, 30 and 35 hrs in a high energy ball milling under optimised process parameters. The milled powders were characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Milled powders exhibit nanocrystalline single phase after 10hrs of milling. Consolidation of 35 hrs milled powder was done by equal channel angular pressing (ECAP) through 90odie channel angle using route A upto three passes with and without back pressure and sintered under controlled environment. Density of ECAPed samples was measured using Archimedes principle. The density is 96% for the sample consolidated with backpressure after two passes after sintering.


2015 ◽  
Vol 787 ◽  
pp. 593-597 ◽  
Author(s):  
S. Harish ◽  
R. Keshavamurthy

Copper based TiC reinforced in-situ metal matrix composite was synthesized by melting copper, hexaflurotitanate and graphite powder in appropriate proportion at a temperature of 1100 °C using stir casting technique. Both copper matrix and copper-TiC composite were subjected to microstructure studies, x-ray diffraction analysis, hardness and tensile test. Optical micrograph shows fine and uniform distribution of TiC particles throughout the matrix. X-ray diffraction analysis confirms the formation of Titanium carbide particles. Developed composite exhibit a significant improvement in hardness and ultimate tensile strength compared with unreinforced copper.


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