Grinding Characteristics of Ejection Powder for Mechanical Plating

The grinding characteristics of Z-irons seem to be closely related to the deposit density in mechanical plating. In this study, ground products were sized, magnetically separated and chemically analyzed. It was found that: (1) The initial rate of dust formation of ZZ-48H was larger than that of ZZ-48. On further pulverization, dust formation decreased slightly for ZZ-48 but continued at the same rate for ZZ-48H. (2) Although the quantiy of dust collected during pulverization differed for ZZ-48H and ZZ-48, the size distribution of the coarse fractions separated from the dusts was similar. (3) The chemical composition of the dust formed during pulverization and that of the non-magnetics of the -60mesh fraction were almost the same for both ZZ-48 and ZZ-48H. (4) The zinc content of the dust formed during pulverization was greater for ZZ-48H than for ZZ-48, indicates more homogeneous alloying of ZZ-48H by thermal treatment. (5) There is a linear relation between deposit density and Zn content for ZZ-48 and its derivatives.