Mikroroughness

Mikroroughness, or micro roughness, refers to the fine-scale irregularities present on a surface at the microscopic level. It describes texture features that lie below the macro-scale roughness and typically span nanometers to micrometers. Micro roughness influences a range of material behaviors and is a consideration in tribology, optics, and coating applications because it governs the real area of contact, light scattering, and adhesion.

Measurement and characterization of mikroroughness rely on specialized instruments such as profilometers, optical interferometers, atomic force microscopes, and scanning electron microscopes. Common roughness metrics include Ra (arithmetical mean roughness), Rq (root-mean-square roughness), and Rz (average peak-to-valley height). For three-dimensional areal roughness, ISO 25178 defines parameters such as Sa and Sq. Measurements depend on the sampling length and the instrument’s resolution, so comparisons require consistent conditions.

The properties and applications of mikroroughness are broad. It affects friction, wear, and sealing because the real contact area is governed by micro-scale asperities. It influences coating adhesion, wettability, and heat or mass transfer. In optics, excessive micro roughness increases light scattering and reduces transmittance; in semiconductor and thin-film processes, nanometer- to micrometer-scale smoothness is often essential for uniform deposition and device performance.

Production and control are achieved through machining, grinding, polishing, chemical etching, and deposition processes. Finishing steps may reduce or tailor micro roughness to meet specifications, while deliberate texturing can introduce controlled micro-roughness to enhance bonding or catalytic activity.