Correlation between milling parameters and microstructure characteristics of nanocrystalline copper powder prepared via a high energy planetary ball mill

Structural evolution in nanocrystalline Cu obtained by high-energy mechanical milling: Phases formation of copper oxides

“…Besides that, the lattice strain value shows a logarithmic increase being under 0.86% for Cu 10 h sample. The D min of the as-milled Cu powder in the literature was reported to be 35 nm [9] and it has been shown that the change of microstructure versus the ball milling conditions (under constant time of the ball milling) depend on only some energy parameters of the milling, for example, average size of crystallite is uniquely defined by energy of the shock, whereas the portion of edge and screw components of dislocation structures depend on a ratio between normal and tangential components of shock [9,10]. On the other hand, the reduction of the grain size was also explained with the balance between dislocation accumulation, and dynamic recovery through formation of subgrain boundary and new grains [31].…”

“…Mechanical milling of elemental powders has been thoroughly investigated in various conditions of energy transfer to prepare non equilibrium materials, such as amorphous [1,2], nanocrystals [3,4], supersaturated solid solutions [5,6] and other metastable phases [7] and to identify the mechanism by which the materials deform to produce nanometer-sized grains [8][9][10]. The deformation structures of materials under mechanical milling were rarely reported, and such are very important for one to get a better understanding of the mechanisms governing the mechanical milling process, since it is still not well understood.…”

On the conditions for the synthesis of bulk metallic glasses by mechanical alloying

“…Murty et al [17] and Joardar et al [18] have shown that amorphisation and formation of intermetallics during MA is decided by the total energy imparted during milling and not the impact energy of the individual balls. Mio et al [19] and Boytsov et al [20] have also shown, for different materials, that total energy input is the important parameter for transformation. Abdellaoui and Gaffet [21] have also shown that neither the impact energy nor the frequency of impacts govern the amorphisation process in a planetary ball mill if taken separately but the power (which is the product of impact energy and the frequency of impacts) only is responsible for ball milled final product, which is supported also by Magini et al [22].…”

Anomalous grain refinement trends during mechanical milling of Bi2Te3

“…The literature trend for Fe has been observed by other authors [34,37,38] in other metals such as Ag, Co, Cu, Ti, Zr [37], Nb [68], the compound NiTi [26], and metalloid Si [37] and well as various ceramic materials [69]. A few other studies have claimed a similar energy trend [70,71] but are more ambiguous since the total energy dose was also varied. By comparison, we are only aware of a single prior report of a positive correlation between dss and E, for the compound FeAl; a study by Kuhrt et al [60] showed this trend in a planetary ball mill (Fritsch Pulverisette 5), although a separate study by Pochet et al [28] using a lower energy vibrating mill (Fritsch Pulverisette-0) indicated the reverse trend with milling intensity.…”