referred to as mass media finishing in which parts to be processed are buried in a vibrating or moving bed of large ceramic particles usually with a fluid added turbine blades having an alumina bond coat 30 40 microns thick and approximately 125 microns of 70 y stabilized zirconia applied by vapor deposition as an insulating coating were chemically stripped under different conditions stripping was performed in an autoclave pressurized only by the natural vapor pressure of the caustic solution the caustic solution was a 50 solution by weight of potassium hydroxide in water two temperatures and several treatment times were evaluated the results are presented in table iii while there is scatter in the data due to small sample sizes and probable bond coat variations some trends are clear at both temperatures short times were effective at ceramic removal with minimum bond coat attack the spike treatment less than about 10 minutes at temperature was effective at both temperatures table iii__________________________________________________________________________ qualitative max depth of aluminum area of tbctemp time attack u03bc depletion attack removal__________________________________________________________________________1 425 u00b0 f spike 2 5 slight isolated total2 34 1 hr 3 mild nearly cont 34 3 34 2 hr 6 3 moderate continuous 34 4 34 4 hr 10 moderate 34 34 5 34 6 hr 19 severe 34 34 6 34 8 hr 21 extremely severe 34 34 7 34 24 hr 24 34 34 34 8 34 48 hr 26 34 34 34 9 350 u00b0 f spike nil nil nil slight residue left10 34 1 hr 7 moderate continuous total11 34.