pinnoitusten

Pinnoitukset are processes that apply a thin layer of material onto a substrate to modify surface properties. They can produce metallic, ceramic, or polymer coatings and are used to improve wear resistance, corrosion protection, hardness, reduce friction, or alter appearance, electrical, or thermal properties.

Common methods include electroplating, where a metal coating is deposited from an electrolytic bath using electric current; electroless plating, which relies on chemical reduction without external current; and physical vapor deposition (PVD) or chemical vapor deposition (CVD). Thermal spraying, powder coating, and traditional paint or varnish coatings are also widely used. Chemical conversion coatings, such as chromate or phosphate treatments, create protective layers through surface reactions rather than a separate coating material.

Materials used in pinnoitukset include metals like nickel, chromium, zinc, copper and their alloys; aluminum and tin; ceramics such as nitrides and carbides; polymer-based coatings; and advanced coatings like diamond-like carbon. Multilayer systems combine different materials to balance properties such as hardness, corrosion resistance, and aesthetics.

Coating thickness ranges from a few nanometers in PVD/CVD to tens of micrometers for electroplated or powder-coated finishes. Important properties include adhesion, hardness, corrosion and wear resistance, coefficient of friction, and appearance.

Applications span automotive, aerospace, machinery, electronics, medical devices, and consumer goods. Coatings serve decorative purposes as well as functional roles such as protection against corrosion or wear, and sometimes thermal management.

Environmental and safety considerations are central to modern pinnoitus. Some coatings involve hazardous substances, driving regulatory pressure and shifts toward safer alternatives. Regulations such as REACH and RoHS influence material choice, waste treatment, and process emissions.