Topographic surface analysis by microscopy with focus variation

What is it?

 All surfaces have deviations from the nominal surface whether by means of manufacturing procedures or inherent to the interface between media. These alterations and deviations are responsible for surface texture.
Topographic surface analysis is a technique where roughness is evaluated as a way of controlling the surface finish. Roughness is also considered as a quality requirement that must be fulfilled in manufacture. Roughness affects the final appearance and functionality.

What is it used for?

This technique allows surface textures to be measured according to the parameters defined by the ISO 4287 e ISO 4288. It also enables specific properties of surfaces to be studied through the methodologies defined by the user. The equipment shows characteristic curves, profile diagrams, registrations of parameter measurements and can also perform statistical evaluation using several types of results filtering and measurement conditions.

Equipment and working conditions

A 3D profilometer of Alicona, InfiniteFocus G4, is used to perform this test. This equipment allows the determination of several parameters of roughness of the parts. The method used is based on the acquisition of the surface topography of the sample through the optical microscopy technique, using light as a measuring way, avoiding any contact with the surfaces to be analyzed. This technique involves a surface capable of reflecting incident light. This method allows the topographic evaluation of micro areas with difficult location and format, using specific software of analysis, which in an evaluation by a traditional linear profile with 2D method would not be possible.

Example of use

• Surface finishing of polymeric parts and comparison with standard references;
• Control of finished metallic parts to guarantee efficiency of use under lubricated conditions;
• Evaluation of geometrical characteristics of micro details on surfaces.