Determination of Silicon in Aluminum and Aluminum Alloys

Abstract

A REVIEW of the literature shows that analytical chemists have been more or less dissatisfied with the status of procedures for the determination of silicon in aluminum and aluminum alloys. The main basis of uncer-

Rapid Gravimetric Determination of Silicon in Aluminum Alloys

“…Many papers have been published on the use of acid mixtures (S, IS, 14,15,18,19) for attacking aluminum alloys in an attempt to speed up the analysis. In general these procedures tend to give low results which have been attributed to two factors-the incomplete oxidation of silicon in the metal to silica and loss of volatile silicon compounds, such as silicon hydride, incurred during acid decomposition (4,5,17), indicating that the proper combination of acids had not been attained. Fuchshuber, however, proposed a method (6) using a mixture of phosphoric, nitric, and sulfuric acids which, besides effectively dissolving the alloy without any apparent loss of silicon by volatilization, oxidized all the silicon present directly to silicic acid upon evaporation of the solution.…”