Be,Li,and Na Redistribution Near a Porcelain/Ni Alloy Interface Shown by Ion Microprobe Mass Analysis

Abstract

During porcelainization the non-preoxidized alloy develops a Be-rich reaction zone in the interface which separates a Be-depleted alloy from a Li and (to a lesser extent Na) depleted region of the ceramic. Thus, Be diffuses to the interface through the alloy Be° → Be⁺⁺ + 2 e- occurs at the interface; some of the electrons are electronically conducted to the porcelain-air interface where they are consumed as 2 e-+ ½ O^o 2 → O⁼, and the resulting negatively charged porcelain surface attracts Li⁺ (and Na⁺).