Analysis of depth of the microporosity in a nickel-chromium system alloy - effects of electrolytic, chemical and sandblasting etching

summary The present study was designed to analyse the average depth of the microporosity of a nickel–chromium (Ni–Cr) system alloy (Verabond II). The metal surface was subject to one of the following surface treatment: (i) Electrolytic etching in nitric acid 0·5 N at a current density of 250 mA cm−2; (ii) chemical etching with CG‐Etch etchant; and (iii) Sandblasting with alumina particles 50 μm. Half of the samples were polished before the surface treatments. The depth of porosity was measured through photomicrographs (500×) with a profilometer, and the data were statistically analysed using an analysis of variance (anova) followed by Tukey's test. The conclusions were (i) Differents surface treatment of the Ni–Cr system alloy lead to different depths of microporosity; (ii) The greatest depth of porosity was observed in non‐polished alloy; (iii) The greatest and identical depth of microporosity was observed following electrolytic etching and chemical etching; (iv) The least and identical depth of microporosity was observed with chemical etching and sandblasting with alumina particles 50 μm, and (v) Chemical etching showed an intermediary depth.