Microstructural Evolution of Alloy Powder for Electronic Materials with Liquid Miscibility Gap

Abstract

The microstructure of powders that are applicable for electronic materials were studied for some systems in which there is a liquid miscibility gap. The characteristic morphologies of an egg-like core type and a uniform secondphase dispersion are shown in relation to the phase diagram, where thermodynamic calculations are a powerful tool for alloy design and the prediction of microstructure. Typical examples of microstructural evolution and properties of Pb-free solders and Ag-based micropowders with high electrical conductivity produced by a gas-atomizing method are presented.

Metastable monotectic phase separation in Co–Cu alloys

“…According to [14], the migration capability of particles is dependent on the cooling rate and miscibility gap temperature interval. However, in a ternary stable miscibility gap system, Ohnuma et al [16] observed that (Ni, Cu) -rich core was always surrounded by a Agrich shell even though the Agrich phase had the lower volume fraction.…”

The formation of Fe Cu composite based on bimetallic nanoparticles

“…They could be used in the manufacturing of microelectronic devices, wiring items, rocket jet nozzles, etc. [4][5][6][7][8].…”

Structural morphologies of Cu–Sn–Bi immiscible alloys with varied compositions

“…During containerless processing such as gas atomization and drop tube methods, the shell always consists of a phase with a lower melting point (termed LMP phase) although the morphology may change from two-layer to multiplylayer core-shell structures as seen in Al-Bi [11], Cu-Fe [1] Ag-CuNi [18] and Fe-Sn-Si [20] immiscible alloys. The reason for this is concluded that the LMP liquid phase generally possesses lower surface energy [1,12].…”