Electrode potentials in fused systems X. Measurement of cation concentration in molten salts using glass membrane electrodes

Abstract

A potentiometric method utilizin g gla ss me mbrane refere nce e lec trod es in a co nce ntration ce ll for the continuous measure me nt in s itu of molte n sa lt co mpos iti on is presented . Re leva nt da ta for th e AgCI-NaCI, AgBr-NaBr, and Ag,SO,-Na2S04 sys tems are give n. Us ing ce ll s of the type M\ IM\A(all), M2 A(a,;)lgla ssI M\A(a,). M,A(aJ IM\where the a' s a re ac tiviti es, the unkn ow n mole fraction X, ca n be ca lc ulated from the eq uation2.303(RT/F)I, -log x;;-wh e re t' is a conce ntra ti on-ind epen de nt cons tant of th e sys te m a nd XII is the conce ntration of M \A in th e referen ce e lec trode. The me th od is capa bl e of measuring X, in molte n salt with an accuracy of better than 5 percent over a co nce ntration range of 10 4App li cation of th e method to ca tions othe r than s ilve r is di sc ussed.

Fatigue and creep damage resistance of a thermal barrier coated superalloy for combustor liners in aero turbines

“…The ceramic layer had ~ 15 % porosity which is normally desired [5,6] and the bond coat also has pores which offer attractive sinks for crack blunting. The bond coated specimens also had an ~100 mm thick Ni 22Co17Cr12.5Al0.6Y layer which contained pores [23]. The substrate (Superni C-263 alloy) in its aged condition shows carbides precipitates in the grains and on the grain boundaries ( Fig.1).…”

“…This is because oxidation is known to reduce the creep life time of bare metals as compared to [20,21,23] or unexposed metals [24] when tested in air/ oxidizing environment. The phase precipitation and phase stability [25] and conventional creep behaviour of the substrate alloy are reported and discussed elsewhere [24,[26][27][28][29].…”

“…It was established that under conditions simulating jet engine applications [7,8], one significant contributor to such spalling is oxidation of the bond coat. Many studies have concentrated on the time to spalling as a function of heat flux [9][10][11][12][21][22][23] and as a function of surface stresses and crack tip opening [12]. Recently it was reported by Ray and Das [1] that a thermal barrier coated (TBC) Superni C263 (Ni20Cr-20Co-6Mo-3Ti-0.5Al-0.6C; wt.…”

Glass-Molten Salt Interactions

“…More recently concentration cells with glass membranes using AgCl-alkali chloride electrodes have been reinvestigated, particularly with applications to reference electrodes in mind (54,81,84,85).…”

“…Glass membrane electrodes in concentration cells appear to be particularly convenient for measuring composition of molten salts. In order to apply Eq 23 for this purpose it was found convenient (84) to rewrite Eq 23 in terms of the mole fractions…”