Mechanical alloying alloys

L. Zaluski, A. Zaluska, P. Tessier, J.O. Strom-Olsen, R. Schulz, Hydrogen absorption in nanocrystalline Mg,Ni formed by mechanical alloying, . /. Alloys Compd. 217 (1995) 245-249. 

H. Yabe, T. Kuji, Thermal stability and hydrogen absorption/desorption properties of Mg1 Al12 produced by bulk mechanical alloying, . /. Alloys Compd. 433 (2007) 241-245. 

M. Khrussanova, E. Grigorova, I. Mitov, D. Radev, P. Peshev, Hydrogen sorption properties of an Mg-Ti-V-Fe nanocomposite obtained by mechanical alloying ,./. Alloys Compd. 327 (2001) 230-234. 

Traditionally, production of metallic glasses requites rapid heat removal from the material (Fig. 2) which normally involves a combination of a cooling process that has a high heat-transfer coefficient at the interface of the Hquid and quenching medium, and a thin cross section in at least one-dimension. Besides rapid cooling, a variety of techniques are available to produce metallic glasses. Processes not dependent on rapid solidification include plastic deformation (38), mechanical alloying (7,8), and diffusional transformations (10). 

Fig. 6. X-ray diffraction traces vs ball milling (mechanical alloying) for Alg5Ni5Fe2Gdg at A, 2 h B, 5 h C, 20 h and D, 80 h. After 80 hours of milling the...

Mechanical alloying is another method of producing dispersion-strengthened metals. In this process, the powdered constituents of the ahoy are treated in an attrition mih. A finely distributed layer of the dispersed phase is distributed on particles of the base metal. Subsequent pressing and sintering strengthens the dispersion (25). 

R. B. Schwarz and Y. He, Proc. International Symposium on Metastable, Mechanically Alloyed and Nanocrystalline Materials (ISMANAM-96), Rome, Italy, 20-24 May, 1996. 

Fig. 4 Stress-strain rate behavior of several mechanically alloyed materials, showing the increase of m values at temperatures corresponding to the incipient melting point for each alloys (data from Ref. [11]).

K. Higashi, T.G. Nieh, and J. Wadsworth, "Effect of Temperature on the Mechanical Properties of Mechanically-Alloyed Materials at High Strain Rates," Acta Metall. Mater., 43 3275 (1995). 

Gaffet, E., Tachikart, M., El Kedim, O., and Rahouadj, R., Nanostructural materials formation by mechanical alloying-morphologic analysis bases on transmission and scanning electron microscopic observations, Mater. Charact. 36, 185, 1996. 

According to the aggregation state of the component elements and the method selected for starting and performing their reaction, several preparative procedures can be considered, such as melting (direct reaction in the liquid state), solid-state synthesis (mechanical alloying), combustion synthesis, etc. 

A review of mechanical alloying processes has been published by Froes et al. (1995). 

Extended homogeneity ranges of intermetallic phases have been studied by Singh et al. (2003) in the Mg-Al system. Powders of the two metals (325 mesh size) were mixed and the mechanical alloying performed using a hardened steel vial and... 

SmCl3 resulted in the reduction only to SmC. From NdCl3 + Ca with the addition of Fe powder, the alloy Nd2Fei7 was obtained. In a discussion of the results it was observed that the products obtained at ambient temperature by mechanical alloying are the same which result from the conventional metallothermic reduction of the rare earth halides. However, the metallothermic reduction requires a temperature of 800-1000°C for the reduction of the chlorides and 1400-1600°C for the fluorides. The products of the mechanical process, on the other hand, are fine, amorphous or microcrystalline, highly reactive metal powders mixed with CaCl2. 

New Routes to Nanomaterials Mechanical Alloying and Mechanochemical Activation... 

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