Alumina as polishing agent for materialographic applications

A successful materialographic preparation is based on the synergy of a professional approach and absolutely reliable machines as well as working materials and auxiliary means. Alumina is a tried and tested versatile polishing agent in materialographic practice. From a chemical point of view, alumina is aluminium oxide (Al2O3). Since the invention of diamond polishes, alumina lost some of its importance and receded into the background. However, it is still used as a reliable polishing agent for softer metals. As opposed to natural polishing materials, polishing agents containing alumina have the advantage of consistent physical and chemical properties. Alumina's hardness ranges below that of silicon carbide and diamond. It is often used to perform the final polish on a softer sample. For alumina polishing, various powders and suspensions containing Al2O3 are available. Before use, alumina powders have to be mixed with distilled water, whereas suspensions can immediately be applied. Such as for grinding, the removal rate of the polishing process depends of different factors: grain size and hardness of the used polishing agent play a role just as the contact pressure applied to the sample.

Polishing with SCAN-DIA Alumina

Choosing the right polishing agent is of major importance for a successful polishing process. SCAN-DIA Alumina has long proven its worth as polishing agent. It is used in a number of laboratories as a reliable polishing agent. SCAN-DIA offers the tried and tested polishing agent alumina (aluminium oxide) in the form of a suspension. Suspensions offer easier and more reliable handling than powders. The ready-mixed suspension is easily dosed for a needs-based use. SCAN-DIA Alumina Suspensions benefit from an excellent homogeneity. During the use of alumina suspensions, the working temperature can be flexibly chosen; moreover, the polishing agent is highly resistant against thermal shocks. SCAN-DIA Alumina is available in 1 litre bottles and in three different grit sizes: 1 µ, 0.75 µ and 0.25 µ. One bottle contains 200 g dry substance dissolved in 1 litre water.