Solid State Amorphization of a Ni-B Alloy by Mechanical Alloying

1990 ◽  
Vol 205 ◽  
Author(s):  
T. Nasu ◽  
C.C. Koch ◽  
K. Nagaoka ◽  
M. Sakurai ◽  
K. Suzuki

AbstractThe main purpose of this work was to investigate the possibility of solid state amorphization of Ni-B crystal powder. A Ni-B alloy powder was obtained by mechanical alloying of Ni and B powder using a conventional ball milling machine. X-ray diffraction and EXAFS measurements were made for the mechanically alloyed samples as a function of milling time. An amorphization reaction was observed in Ni64B36 at 400 h of milling time. The long range order of the crystalline Ni phase diminished with an increase of solution of B into the Ni matrix. This suggests that the solution of B atoms into the Ni crystalline phase, forced by mechanical alloying, plays an important role in the crystalamorphous transformation.

2005 ◽  
Vol 04 (05n06) ◽  
pp. 1025-1028
Author(s):  
I. MANNA ◽  
P. NANDI ◽  
B. BANDYOPADHYAY ◽  
P. M. G. NAMBISSAN ◽  
K. GHOSHRAY ◽  
...  

The microstructural evolution at different stages of milling of a ternary powder blend of Al 50 Ti 40 Si 10 composition was monitored by X-ray diffraction, high-resolution transmission electron microscopy, positron annihilation spectroscopy and 27 Al nuclear magnetic resonance. Ball-milling leads to alloying, nanocrystallization and partial solid state amorphization, either followed or accompanied by strain-induced nucleation of nanocrystalline intermetallic phases from an amorphous solid solution.


2004 ◽  
Vol 449-452 ◽  
pp. 249-252 ◽  
Author(s):  
Jung Il Lee ◽  
Tae Whan Hong ◽  
Il Ho Kim ◽  
Soon Chul Ur ◽  
Young Geun Lee ◽  
...  

High silicon Al-Si alloy powders having nanocrystalline structures have been produced by mechanical alloying process. Microstructures in mechanically alloyed Al-Si powders were investigated by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses were also carried out to characterize lattice constant, crystallite size and misfit strain. Effective milling time for the formation of nanocrystalline microstructure was thought to be approximately 12 hours, and the sizes of Al and Si crystallites in mechanically alloyed powders after longer than 12 hours of milling were reduced to about 30nm and 70nm respectively, in Al-70 mass% Si alloy system. The misfit strains increased with milling time up to 240 hours, and saturated to 5.73×10-3 and 4.39×10-3 for Al and Si crystallites, respectively.


Author(s):  
Mahmoud Chemingui ◽  
Chahida Mnasri ◽  
Christelle Nivot ◽  
Arnaud Tricoteaux ◽  
Yannick Lorgouilloux ◽  
...  

Abstract A new nanocrystalline Fe71B23Nb6 alloy powder was prepared by mechanical alloying. The phase transformation and morphological and microstructural properties of the as-prepared alloy were investigated by scanning electron microscopy, laser granulometry, and X-ray diffraction with respect to the milling time (0- 200 h). During the milling process, it was observed that the dissolution of Nb and B atoms into the Fe matrix formed solid solutions of Fe (Nb), Fe (B), Fe23B6, Fe2B, and Fe (Nb, B). Moreover, the insertion of B atoms into the Nb network generated the Nb (B) phase. Furthermore, the minimum crystallite size was measured as approximately 1 nanometer. In addition, the dislocation density gradually increased with the extension of the milling time, and the crystallization of the partially amorphous phase occurred after 200 h of milling.


2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.


2012 ◽  
Vol 496 ◽  
pp. 379-382
Author(s):  
Rui Song Yang ◽  
Ming Tian Li ◽  
Chun Hai Liu ◽  
Xue Jun Cui ◽  
Yong Zhong Jin

The Cu0.81Ni0.19 has been synthesized directly from elemental powder of nickel and copper by mechanical alloying. The alloyed Cu0.81Ni0.19 alloy powders are prepared by milling of 8h. The grain size calculated by Scherrer equation of the NiCu alloy decreased with the increasing of milling time. The end-product was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM)


2020 ◽  
Vol 1002 ◽  
pp. 12-20
Author(s):  
Tarik T. Issa ◽  
Sadeer M. Majeed ◽  
Duha S. Ahmed

Elements of high purity (99.999) ,were used to prepare the alloy , Bi ,Sn,Zn and Cu .Two types alloy Bi – Sn – Zn and Bi – Sn – Cu were prepared by mechanical alloying technique (MA) .Annealing at 100 °Cfor 8 hours was applied for the resulting alloys . X-ray diffraction and differential scanning colorimetriy were tested for the two types of alloy before and after annealing. The best results was noticed in the ternary alloythat prepared at 4 hours milling time ,and annelid at 100 °C, for 8 hours ,under static air.


2011 ◽  
Vol 672 ◽  
pp. 157-160
Author(s):  
Ionel Chicinaş ◽  
Viorel Pop ◽  
Florin Popa ◽  
Virgiliu Călin Prică ◽  
Traian Florin Marinca ◽  
...  

The formation of quaternary 76Ni17Fe5Cu2Cr (wt. %) alloy by mechanical alloying is investigated. The elemental powders of Ni, Fe, Cu and Cr where milled in argon atmosphere in a planetary ball mill for time up to 20 h. Formation of the alloy was checked by X-ray diffraction studies. It is found that the rapid formation of the alloy lead to the rapid establishment of an equilibrium between the welding and fracture process during milling, leading to a constant particle size distribution over a big range of milling time. The morphology of the powders, studied by scanning electron microscopy (SEM) confirms the rapid increase in size. The particle size distribution and the flowability of the powders are also analyzed as a function of milling time. Enhanced magnetization was found for the milled samples, compared to a cast alloy.


2013 ◽  
Vol 873 ◽  
pp. 217-220
Author(s):  
Min Xu ◽  
Qun Jiao Wang

The paper has described the formation of nanocrystalline Mn80Bi20powders by mechanical alloying and studied the changes of structure and magnetic properties of the powders during the process of ball milling by using X-ray diffraction and saturation magnetization σsmeasurements. The solid solubility of bismuth in manganese increases with milling time and tends to a stable value after 80h milling. The σsof Mn80Bi20increases abruptly with milling time at the early stage and begins to decrease after 15h. At the time of 15h, the σsreaches a maximum, which is about 7Am2/kg. The result shows an interesting information that the antiferromagnetic Mn and the diamagnetic Bi produce ferromagnetic Mn80Bi20in process of mechanical alloying.


2005 ◽  
Vol 896 ◽  
Author(s):  
Xiaoying Zhu ◽  
Mirko Schoenitz ◽  
Vern K. Hoffmann ◽  
Edward L. Dreizin

AbstractMechanically alloyed powders with the composition Al0.7Li0.3 are synthesized. Materials milled for different times are studied using electron microscopy, x-ray diffraction, and thermal analysis. A solid solution of Li in Al (α-phase) is formed with as much as 10 at % of dissolved Li. The LiAl intermetallic δ-phase is readily produced by mechanical alloying but disappears after extended milling times. The final product of milling for 102 hours consists of an x-ray amorphous phase. Mechanically alloyed powders heated in inert environment exhibit several weak exothermic reactions between 420 and 700 K, and two endothermic reactions, around 810 and 870 K. All the observed relaxation processes become less pronounced and eventually become undetectable as the milling time increases and an amorphous material is produced. Ignition experiments performed for the powders coated on an electrically heated filament showed that the powders ignited in the vicinity of 1250 K. An experimental setup for studying combustion of reactive mechanically alloyed powders is developed and initial experimental results are described.


2012 ◽  
Vol 531-532 ◽  
pp. 437-441 ◽  
Author(s):  
Qi He ◽  
Tao Liu ◽  
Jian Liang Xie

Fe-Ni-Cr alloy powders with the different components were prepared by Mechanical Alloying (MA). The phase structure, grain size, micro-strain and lattice distortion were determined with X-ray diffraction. The morphology and particle size of the powders were observed and analyzed using a field emission scanning electron microscopy. The results showed that the Fe-Ni-Cr nanocrystalline powders could be obtained by MA. The ball milling time could be reduced with increasing amount of Cr, resulting the formation of Fe-Ni-Cr powders. With the increasing amount of Cr, the speed of Ni diffusion to Fe lattice approaching saturation became more rapid. The particle size got smaller as the ball milling went further; the extent of micro-strain and distortion of lattice intensified; the solid solubility of Ni and Cr in Fe was increased. Finally the super-saturated solid solution of Fe was obtained.


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