The Effects of Acid Etching on the Morphology and Properties of Medical Grade Alumina and Zirconia Surfaces for Prosthetics

Abstract In this study we modify and functionalize the surface of alumina and zirconia ceramics for medical applications using chemical etching with mixtures of sulfuric, nitric, hydrofluoric acids and peroxide. After etching, the impact of processes on surface development, chemical composition, and topography is studied to select the most effective process of surface development. Medical grade alumina and zirconia ceramic powders have been chemically etched with selected three kinds of acidic solutions : 1.sulfuric and nitric acid, 2.sulfuric acid and peroxide, 3.fluoric acid various diluted aqueous solution during the selected time periods. Following heat treatment was performed and the samples characterization were undertaken: morphology and chemical composition , phase composition, functional group determination, and the specific surface area and porosity evaluation.. Comparing the results raised from acidic etching, it was noticed that the use of H2SO4:HNO3 solutions causes sulphur residues in ceramic in the form of sulphates. The application of HF negatively affects the structure of the material and cause agglomeration. The most advantageous modification of ceramic powders was application of piranha solution, the obtaining surface development was achieved, satisfactory degree of agglomeration and post-process pollution.