Solid-Solution-Formation by MM of the Ag-70at Cu alloy

摘要

The solid-solution-formation of the well known Ag-70Cu (at%) has been chosen to study efficiency, Fe- contamination and particle-morphology evolution in a Simoloyer CM01-21 high energy mill. Grinding media/powder ratio was varied at constant media load of 1500g. Samples for solid-solution and for morphology-evolution were taken out at different times. The media/powder ratio was compensated by discharging the corresponding load of balls for the extracted sample. Solid-solution-formation was obtained after 79.2, 43.2 and 18 ks for the 10:1, 20:1 and 50:1 ratio respectively. Fe-contamination was always lower than 1.0%. Solid-solution-formation mechanism for this ductile material under MM seems to be related to the flake - formation-mechanism occurring during the collision of grinding media. Additionally, Cycle Operation has been applied which resulted in rapid flaking with quasi-disappearing ductility followed by shear-stress to break the flaky structure repeatedly. Since a higher collision rate versus shear and friction effect is expected to cause less abrasive wear on the milling tools, the Fe-contamination was expected and found in low range. Material's characterization is given by SEM, XRD and TEM.