PREPARATION AND CHEMICAL-ANALYSIS OF HIGH-PURITY IRON-ZINC ALLOYS

We have produced and chemically analyzed a series of high purity iron-zinc alloys with iron concentrations in the range 4-27 wt. %. The technique involved slow diffusion of high purity zinc with small particle iron powder. We produced alloys within the four main iron-zinc phases, Zeta, Delta, Gamma-1, and Gamma to aid in the identification of the intermetallic phases formed in commercially produced galvanneal steel coatings. The diffusion technique produces iron-zinc alloys which are suitable as instrument calibration standards for galvanneal producers and users. A chemical titration technique which measures iron concentration to within 0.5 wt. % was also refined. In determining the bulk iron concentrations of the samples, we have compared the accuracy of the wet chemical technique with Induction Coupled Plasma spectroscopy. Homogeneity was measured using an electron microprobe and a scanning transmission electron microscope. The data show that samples are homogeneous to greater than 98% of the mean iron concentration.