Coarsening Kinetics of Pb Phase in a Nanocomposite Alloy Produced by Mechanical Alloying in Immiscible Al-Pb System and the Influence of Cu Addition on It

Abstract

Coarsening kinetics of Pb phase in a nanocomposite alloy produced by mechanical alloying in immiscible Al-Pb system and the influence of Cu addition on it were studied by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Results show that when annealing at 573, 623, 673 and 723 K for different time, the relation of average particle size of Pb phase in Al-Pb nanocomposite alloys to time obeys the cube law even though the size of the constituent phase is in the nanometer range. The coarsening activation energy of Pb phase is 84.8 kJ/mol, close to the grain boundary self-diffusion activation energy of Al matrix. This indicates that the coarsening of Pb phase is controlled by grain boundary diffusion. Adding Cu decreases the coarsening rate of Pb phase, primarily by reducing the interfacial energy through Cu segregation at the Al/Pb interface. The coarsening activation energy of Pb phase is increased by the addition of Cu.

Morphogenesis mechanisms in the hydrothermal growth of lead-free BCZT nanostructured multipods

“…The resulted loose particles can be originated from the lattice mismatch or the crystallographic incompatibility between HZTO-NWs and CZTO and BCZT products. 45,52 A similar evolution was reported in ref. 9,14,45 These results indicate that BCZT 1D nanostructures cannot be obtained by using HZTO-NWs as templates in hydrothermal process at least under stagnant conditions.…”

Conductivity of Multicomponent Alloy under Solid Solution Short-Range Order Cluster Model

“…In engineering practice, multicomponent alloys are usually formed by adding an appropriate element solid solution to metallic simple substances (i.e., alloying method) for improving the physical properties of metals and by virtue of whose material development mode characterized by broadness (i.e., different solid solution strengthening components introduced in the same matrix will show different physical properties by forming different phases) and specificity (i.e., it will show the optimal physical property at a specific alloy composition ratio), numerous solid-solution-structure-based industrial alloys in multicomponent system have been formed, with the emphasis on improvement of comprehensive mechanical strength and electrical conductivity. , For example, the excellent electrochemical characteristics unique to both Bi and Si make Al–Bi–Si alloy , widely used as an electrical contact switch material; featured by regular fibrous structure, Cu–Pb–Al, Cu–Pb–Zn and other alloys still maintain unique lubrication characteristics of Pb, thus becoming good bearing materials. A general lack of knowledge about the traceability of composition formation of industrial alloys has directly led to a long-term massive empirical exploration for the components of high-quality alloys and a great waste of energy and financial resources in the researches on new alloys.…”