Norihisa Mori

EPMA Analysis of Corroded Hot-Dip Galvanized Carbon Steel using the “Phase Map Maker” Software

A test piece of hot-dip galvanized steel was treated with a salt spray test. This treatment, according to JIS Z 2371, is a neutral 5% aqueous sodium chloride solution sprayed 1008 hours at 35°C. The test pieces from before and after the salt spray test were cut and made into polished cross sections. These samples were analysed and confirmed to have a η layer (Zn), a ζ layer (FeZn13) and a δ1 layer (FeZn7), which is the general structure of hot-dip galvanized steel [1]. A scatter diagram analysis was applied to element maps from the two test pieces.

Development of an Automated Phase Analysis Procedure for Multi-Component Samples in EPMA

EPMA systems, with their high analytical accuracy, are ideal for the identification of intermetallic compounds, minerals, and other phases. In the past, phases were differentiated using a scatter diagram analysis on elemental map data. An intermetallic compound or a mineral can be recognizable as a cluster of compositional data points in the corresponding scatter diagram. The phase analysis program, previously used by EPMA, produced a phase map by plotting each pixel on the map, using a specific color for each cluster.

The Present State of Chemical State Analysis in EPMA and WD-SXES

Chemical state analysis in EPMA examines changes in the characteristic X-ray spectrum reflecting the electronic structure of a specific element in a material. Waveforms of characteristic X-rays reflecting low energy electronic structures often change according to the chemical bonding state. Chemical state analysis in EPMA focuses on these changes in the waveform. This analysis determines the composition of the chemical state identifies the chemical state by comparing the waveforms of an unknown material and a reference material.