EDX analysis of RE enriched phase on the working surface of mischmetal doped cemented carbide cutting insert

As is known that there are overlap phenomena of EDX spectral lines between Lβ1 of La and Lα of Pr, Lβ1 of Ce and Lα of Nd, LIIIab of La and Lβ1 of Pr, LIIIab of Ce and Lβ1 Nd. As a result, it is a common practice ignoring the existence of the elements Pr and Nd in the analysis of the rare earth (RE) containing phase in mischmetal doped alloy with La and Ce as the main composition. In the present paper, curve fitting method in the EDX analysis of the enriched RE phase on the working surface of La, Ce, Pr and Nd containing mischmetal doped cemented carbide cutting insert was introduced, and the directional migration behavior of La, Ce, Pr and Nd from the inside of the alloy to the working faces of the as-sintered insert during the turning process was investigated. It is shown that for the EDX analysis of the similar elements with overlapped spectral lines, the curve fitting method should be used in the identification of the existence of the similar elements. For the EDX analysis of RE phase in La, Ce, Pr and Nd containing mischmetal doped alloy, even if the Pr and Nd elements are ignored, the judgment of behavior on La and Ce will not be affected; nevertheless, the whole information on the behavior of La, Ce, Pr and Nd in the alloy will be missed. During the machining of C and S containing materials, La, Ce, Pr and Nd in the mischmetal doped WC-Co alloy can directionally migrate to the working surface of the cutting insert, however the migration is asynchronous. Ce, Pr and Nd atoms can move faster than La atoms.