•The copper coordination agent of CN− was replaced by HEDP.•The electrodeposition mechanism of the copper plating system with HEDP was studied.•The coordinate compounds CuL26− and Cu(OH)2L28− formed at different PH.•The copper nucleation in the HEDP system follows diffusion-limited growth mechanism.The specific forms of the coordination compounds were calculated and the specific process of copper reduction was investigated in non-cyanide alkaline baths with 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP, or H4L) complexing agent. The results indicate that Cu2+ coordinated with HEDP molecules to form CuL26− coordination compound, and OH− would coordinate with CuL26− to form more stable Cu(OH)2L28− complex as pH increased. The electrochemical reduction of Cu2+ on glassy carbon electrode is composed of individual reduction processes of the above-mentioned two coordination complexes. The reduction processes are irreversible and controlled by diffusion. As the overpotential increased, the low-coordinate compound CuL26− was reduced to copper first, following by the reduction of high-coordinate compound Cu(OH)2L28−. The copper electrodeposition involves nucleation process, and the electrocrystallization is consistent with progressive nucleation in three dimensions.Download high-res image (73KB)Download full-size image

Powder injection molding (PIM) opens new possibilities to process complex Sr-ferrite components for magnetic applications. In the present study, new binder system with the addition of microcrystalline wax (MW) was used for the Sr-ferrite powder injection molding. The optimum binder composition was determined based on rheological measurement, mircrostructure observation by SEM, thermal change by DSC and debinding process. The results indicated that MW with 10 vol.% addition in the binder system containing high density polyethylene (HDPE), paraffin wax (PW) and stearic acid (SA) decreases the defects of the green parts after solvent debinding because the distribution of the binder system between the Sr-ferrite particles becomes more homogeneous. Using the proper binder system containing MW, the defect-free and dense Sr-ferrite ceramics can be prepared after solvent and thermal debinding and sintering. Based on the experimental results, the effects of MW microcrystalline wax on the solvent debinding of the Sr-ferrite ceramics were detailed discussed.