Preparing Amorphous/Nanocrystalline TiNbZrTaFe Powder by Mechanical Alloying

2015 ◽  
Vol 816 ◽  
pp. 671-675
Author(s):  
Li Ming Zou ◽  
Yi Xiang Cai
Keyword(s):  
Mechanical Alloying ◽  
Milled Powder ◽  
Nanocrystalline Structure ◽  
Alloy System ◽  
Amorphous Structure ◽  
Liquid Region ◽  
Matrix Composites ◽  
Fe Content ◽  
Glass Matrix Composites ◽  
Milled Powders

(Ti69.7Nb23.7Zr4.9Ta1.7)100-xFex(x=0, 2, 6, and 10) nanocrystalline, nanocomposite and amorphous powders were synthesized by mechanical alloying from blended element powder. The structural transition for the milled powders was confirmed by X-ray diffraction (XRD). Results shows with the increasing Fe content in alloy system, the glass forming ability become larger. Only forx=10, it can obtain nearly completely amorphous structure with wide super cooled liquid region (△Tx=122 K). Forx=2 and 6, residual nanocrystals of the β-Ti structure dispersed in the amorphous matrix. Forx=0, the milled powder has full nanocrystalline structure. These as-milled powders offer the potential to fabricating the bulk glass material or nanocrystal/glass matrix composites by powder metallurgy for biomedical use.

scholarly journals Synthesis, Characterization and Mechanical Behaviour of Al2O3, TiO2, and Cu Reinforced Al 7068 Nanocomposites

2020 ◽  
Vol 7 ◽  
Author(s):  
V. Sathiyarasu ◽  
D. Jeyasimman ◽  
L. Chandra Sekaran
Keyword(s):  
Mechanical Alloying ◽  
Gas Flow ◽  
Research Work ◽  
Exothermic Reaction ◽  
Milled Powder ◽  
Hardness Test ◽  
Matrix Composites ◽  
Weight Percentage ◽  
Transmission Electron ◽  
Nanocomposite Powders

This present research work aims at fabrication of AA7068 metal matrix composite reinforced with a different weight percentage of Al2O3, TiO2 and Cu (0 wt.%, 2 wt.%, and 4 wt.%) nanopowders through mechanical alloying of 30 hrs which is produced using powder metallurgy route. The consolidation pressure of 500 MPa was applied for compaction of the composite and sintered at a temperature of 600°C for two hrs in the presence of argon gas flow. An XRD result reveals that there are no intermetallic compounds formed in the milled powder after 30 hr of mechanical alloying. The reinforcement particles were well embedded and uniformly distributed in matrix composites was confirmed by bright-field emission transmission electron microscopy (FETEM) image and selected area diffraction (SAD) ring pattern. From the DSC curve of AA 7068–2.0 wt. % Al2O3, TiO2 and Cu nanocomposite powders after 30 hrs of mechanical alloying., the endothermic peak at 536.85°C corresponds to the melting of aluminium which was followed by a steady-state exothermic reaction at 579.51°C was obtained. The green density and sintered density of prepared nanocomposites were calculated and compared. Brinell hardness test has been conducted and the maximum value of 192 BHN was obtained by adding a weight percentage of 2 wt. % of Al2O3, TiO2 and Cu particles.

scholarly journals Glass formation in a (Ti, Zr, Hf)–(Cu, Ni, Ag)–Al high-order alloy system by mechanical alloying

2003 ◽  
Vol 18 (9) ◽  
pp. 2141-2149 ◽  
Author(s):  
L. C. Zhang ◽  
Z. Q. Shen ◽  
J. Xu
Keyword(s):  
Glass Transition ◽  
Mechanical Alloying ◽  
Glass Formation ◽  
Melt Spinning ◽  
Glassy Alloy ◽  
Alloy System ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
High Order ◽  
Liquid Region

In this work, glass formation under high-energy ball milling was investigated for a (Ti0.33Zr0.33Hf0.33)50(Ni0.33Cu0.33Ag0.33)40Al10 high-order alloy system with equiatomic substitution for early and late transition-metal contents. For comparison, an amorphous alloy ribbon with the same composition was prepared using the melt-spinning method as well. Structural features of the samples were characterized using x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. Mechanical alloying resulted in a glassy alloy similar to that obtained by melt spinning. However, the glass formation was incomplete, and a small amount of unreacted crystallites smaller than 30 nm in size still remained in the final ball-milled product. Like the melt-spun glass, the ball-milled glassy alloy also exhibited a distinct glass transition and a wide supercooled liquid region of about 80 K. Crystallization of this high-order glassy alloy proceeded through two main stages. After the primary nanocrystallization was completed, the remaining amorphous phase also behaved as a glass, showing a detectable glass transition and a large supercooled liquid region of about 100 K.

Manufacture of CNTs-Al Powder Precursors for Casting of CNTs-Al Matrix Composites

2013 ◽  
Vol 765 ◽  
pp. 353-357 ◽  
Author(s):  
Seh Yun Ko ◽  
Bo Young Kim ◽  
Yong In Kim ◽  
Taeh Yeong Kim ◽  
Ki Tae Kim ◽  
...  
Keyword(s):  
Milled Powder ◽  
Casting Process ◽  
Matrix Composites ◽  
Aluminium Powder ◽  
Powder Precursor ◽  
Al Powder ◽  
Al Matrix Composites ◽  
Electroless Ni ◽  
Al Matrix ◽  
Milled Powders

CNTs-Al matrix composites are considered to be promising heat dissipating materials because thermal conductivity can potentially be improved whilst their density is reduced. Although casting has many advantages in the fabrication of large, complex components, this process cannot be easily employed when manufacturing CNTs-Al composites. In order to produce CNTs-Al matrix composites by casting a CNTs-Al powder precursor was manufactured using mechanical milling and electroless plating processes. Aluminium powder with CNTs of 10 wt.% and 20 wt.% were mixed and ball milled using a horizontal mill. After milling for 3 hrs., the milled powder exhibits a flattened morphology with a band-type distribution of CNT clusters observed within the aluminium particles. Prolonged milling of up to 24 hrs. introduces an equiaxed particle shape for the milled powders with a uniform distribution of CNTs within the aluminium particles. However, as milling time increases, the CNTs become fractured by ball-to-ball collisions. There was no reaction evident between the aluminium and the CNTs at milling times up to 24 hrs. In order to improve the wettability between the CNTs-Al powder precursor and Al melt during the casting process, electroless Ni plating was performed. The processing time for the Ni-plating affects the uniformity of the coating layer. For a uniform coating condition, the average thickness of the coating was ~1.87 μm, with no evidence of gaps between the milled powders and coatings observed.

Production of Cu-Hf-Ti Bulk Glassy Composites by Mechanical Alloying and Spark-Plasma Sintering

2006 ◽  
Vol 118 ◽  
pp. 655-660 ◽  
Author(s):  
Pyuck Pa Choi ◽  
Ji Soon Kim ◽  
Hyeong Suk Choi ◽  
Dae Hwan Kwon ◽  
Young Soon Kwon
Keyword(s):  
Mechanical Alloying ◽  
Spark Plasma Sintering ◽  
High Energy ◽  
Amorphous Structure ◽  
Liquid Region ◽  
Scanning Calorimetry ◽  
Plasma Sintering ◽  
Stage Crystallization ◽  
Spark Plasma ◽  
Dsc Analyses

This work reports on the production of Cu-Hf-Ti bulk glassy composites through a powder metallurgical route, i.e. by mechanical alloying and subsequent spark-plasma sintering. Powders of Cu60Hf30Cu10 and Cu60Hf25Ti15 composition were prepared using a high-energy planetary ball-mill. Both alloys nearly showed a fully amorphous structure with only a small fraction of residual HCP Hf grains left after 50 h of milling. Differential scanning calorimetry (DSC) analyses of the milled glassy powder revealed a two-stage crystallization process for both compositions. However, the released crystallization enthalpy was substantially larger for the Cu60Hf25Ti15 alloy than for the Cu60Hf30Ti10 alloy, suggesting that the former comprises a higher fraction of the amorphous phase than the latter. Both powders showed distinct glass-transition with a large super-cooled liquid region. Consolidation of Cu60Hf25Ti15 powder was carried out by means of spark-plasma sintering at applied pressures of 200 and 500 MPa, choosing a sintering temperature within the super-cooled liquid region (T = 753 K). The sintered compacts exhibited some pores and interparticle boundaries.

scholarly journals Microstructural Investigations of Rapidly Solidified Al-Co-Y Alloys

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
B. Avar ◽  
M. Gogebakan ◽  
M. Tarakci ◽  
Y. Gencer ◽  
S. Kerli
Keyword(s):  
Melt Spinning ◽  
Alloy System ◽  
Supercooled Liquid ◽  
Amorphous Structure ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Glass Forming ◽  
Rapidly Solidified

The alloys with different compositions in the Al-rich corner of the Al-Co-Y ternary system were prepared by conventional casting and further processed by melt-spinning technique. The microstructure and the thermal behavior of the alloys were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). It was found that only rapidly solidified Al85Co7Y8alloy exhibited the best glass forming ability (GFA) and a fully amorphous structure. Besides, Al85Co13Y2and Al85Co2Y13alloy ribbons were fully crystalline, whereas Al85Co10Y5and Al85Co5Y10alloy ribbons consisted of some crystalline phases within an amorphous matrix. The SEM results showed the same trend that the crystalline phase fraction decreases with the approaching into best glass former. From DSC results, only Al85Co7Y8amorphous alloy exhibited a glass transition temperature (Tg) at 569 K, and its supercooled liquid region (ΔTx=Tx−Tg) was found to be 17 K. Moreover, other calculated GFA parameters for this alloy system were also discussed.

Thermal and Phase Evolutions of As-Milled Powders Fabricated by Mechanical Alloying in the TiH2-C System

2006 ◽  
Vol 510-511 ◽  
pp. 366-369 ◽  
Author(s):  
Sung Yeal Bae ◽  
In Sup Ahn ◽  
Tek Kyung Sung ◽  
Dong Kyu Park
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Mechanical Alloying ◽  
Milled Powder ◽  
Hydrogen Gas ◽  
Carbon Powder ◽  
Unstable Phase ◽  
Particle Size Analyzer ◽  
Vacuum Atmosphere ◽  
Milled Powders

Nano-TiC powders were fabricated for mechanical alloying (MA) by shaker mill using the TiH2 powders mixed carbon powder. For mechanical alloying, titanium hydride was easily breaking alloy and easily decomposed titanium particles and hydrogen gas. The decomposition titanium powders in TiH2 powders were very fine particle size and unstable phase. And it easily reacted to carbon ;(TiH2 + C 􀃆 TiC + H2). The effects of mechanical allyoing, morphology, phase and particle size were evaluated with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), TG/DTA and particle size analyzer. As-milled powders for 10 hours were successfully synthesized powders of TiC phase, mean particle 300nm size. And as-milled powder for 1 hour was included unstable phase, was annealed for 1 hour at 400°C-1300°C in 1x10-3torr vacuum atmosphere. Unstable phase was changed to recrystallize phase by heat treatment. After heat treatment for 1hour using as-milled powders, it was included many types of titanium oxide at temperature below 1000°C, was formed single phase of TiC at temperature over 1000°C.

scholarly journals Optimization of milling speed and time in mechanical alloying of ferritic ODS steel through taguchi technique

2021 ◽  
Vol 12 ◽  
pp. 25
Author(s):  
Ganesan Dharmalingam ◽  
Murali Arun Prasad ◽  
Sachin Salunkhe
Keyword(s):  
Mechanical Alloying ◽  
Mechanical Milling ◽  
Milling Time ◽  
Influencing Factor ◽  
Oxide Dispersion Strengthened ◽  
Amorphous Structure ◽  
Ods Steel ◽  
High Impurity ◽  
Selection Of ◽  
Milled Powders

The oxide dispersion strengthened (ODS) ferritic steels are one of the most important in fuel cladding materials for 4th Generation nuclear reactors because of their excellent mechanical properties such as irradiation resistance, swelling resistance, and elevated temperature tensile/compressive strength. Mechanical alloying (MA) is one of the most promising routes for developing nanocrystalline ferritic ODS steel materials. For the production of nanocrystalline ferritic ODS steel powders, the most influencing factor is the milling speed and milling time during the mechanical alloying process. With the improper selection of milling time and speed, the final milled powders become an amorphous structure consisting of high impurity inclusions in the microstructure, and strength was also affected. In order to overcome these drawbacks, the present investigation was taken into account for the selection of appropriate mechanical milling speed and time, which was optimized through Taguchi analysis followed by the MA process. The optimized mechanical milling speed and time of milled powders were characterized through X-Ray Diffraction Analysis (XRD) and Scanning Electron Microscope (SEM).

New Fe-B-P-Cu Nanocrystalline Soft Magnetic Alloys with High Js Combined with Low Coercivity Hc

2012 ◽  
Vol 508 ◽  
pp. 99-105
Author(s):  
Ze Qiang Zhang ◽  
Parmanand Sharma ◽  
Akihiro Makino
Keyword(s):  
Raw Materials ◽  
Nanocrystalline Structure ◽  
Nanocrystalline Alloy ◽  
Amorphous Structure ◽  
Magnetic Alloy ◽  
Soft Magnetic ◽  
Soft Magnetic Alloy ◽  
Air Atmosphere ◽  
Fe Content ◽  
Magnetic Softness

Fe-Si-B Amorphous Alloys with Less than 80 at% Fe Are now in Practical Use due to their Excellent Magnetic Softness (Low Coercivity Hc) Combined with Rather High Saturation Magnetic Polarization (Js) which Basically Owing to the Lack of Intrinsic Magnetic Anisotropy and the High Fe Content, Respectively. In Order to Obtain High Js, High Fe Content Is Required. However, Alloys with High Fe Content Exceeding the Limit Usually Have the as-Quenched Structure Consisting of Coarse α-Fe Grains in the Amorphous Matrix, which Results in Inferior Magnetic Softness. We Have Developed a New Fe85.2B10P4Cu0.8 Nanocrystalline Soft Magnetic Alloy Ribbon (with 5 mm in Width and about 20 µm in Thickness) Made from Industrial Raw Materials in Air Atmosphere. The as-Quenched Structure of Fe85.2B10P4Cu0.8 Alloy Has Heterogeneous Amorphous Structure (a Large Amount of Extremely Small α-Fe Clusters in Addition to Amorphous Phase). Homogeneous Nanocrystalline Structure Composed of α-Fe Grains with a Size ~19 nm Was Realized by Crystallizing the Hetero-Amorphous Alloy. The Nanocrystalline Alloy Exhibit High Js ~ 1.83 T (Comparable to the Commercial Fe-3.5 Mass% Si Steel) and Extremely Low Hc ~ 6.0 A/m. Additionally the Alloy Has a Large Economical and Industrial Advantage of Lower Material Cost and Good Reproductivity, which Has a High Potential for the Power Applications.

Tensile softening of metallic-glass-matrix composites in the supercooled liquid region

2012 ◽  
Vol 100 (12) ◽  
pp. 121902 ◽  
Author(s):  
J. W. Qiao ◽  
Y. Zhang ◽  
H. L. Jia ◽  
H. J. Yang ◽  
P. K. Liaw ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Glass Matrix ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Matrix Composites ◽  
Glass Matrix Composites ◽  
Tensile Softening
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