The kinetics of composite particle formation during mechanical alloying
Document Type
Article
Publication Date
3-1993
Department
Department of Materials Science and Engineering
Abstract
The kinetics of composite particle formation during attritor milling of insoluble binary elemental powders have been examined. The effects of processing conditions (i.e., mill power, temperature, and charge ratio) on these kinetics were studied. Particle size distributions and fractions of elemental and composite particles were determined as functions of milling time and processing conditions. This allowed the deduction of phenomenological rate constants describing the propensity for fracture and welding during processing. For the mill-operating conditions investigated, the number of particles in the mill generally decreased with milling time, indicating a greater tendency for particle welding than fracture. Moreover, a bimodal size distribution is often obtained as a result of preferential welding. Copper and chromium "alloy" primarily by encapsulation of Cr particles within Cu. This form of alloying also occurs in Cu-Nb alloys processed at low mill power and/or for short milling times. For other conditions, however, Cu-Nb alloys develop a lamellar morphology characteristic of mechanically alloyed two-phase ductile metals. Increasing mill power or charge (ball-to-powder weight) ratio (CR) increases the rate of composite particle formation.
Publication Title
Metallurgical Transactions A
Recommended Citation
Aikin, B.,
&
Courtney, T.
(1993).
The kinetics of composite particle formation during mechanical alloying.
Metallurgical Transactions A,
24(3), 647-657.
http://doi.org/10.1007/BF02656633
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/4451