Lihvimise

Lihvimise (Estonian for polishing) refers to the process of smoothing a surface by abrasion to reduce irregularities, improve fit and appearance, and enhance functional properties such as reflectivity or corrosion resistance. The term covers a range of finishing operations applied to metals, glass, ceramics, plastics, wood and composites.

Basic methods include mechanical polishing, where abrasive grains are held in a pad or wheel and moved over the workpiece in wet or dry conditions. Common abrasives are silicon carbide, aluminum oxide, emery, and, for final finishes, diamond paste or diamond-impregnated tools. Chemical-mechanical polishing (CMP) combines polishing with a chemically active slurry to accelerate material removal on flat, delicate surfaces, while electro-polishing uses an electric current to remove material from metal surfaces.

Polishing is usually performed in stages, starting with coarse grains to remove defects, followed by progressively finer abrasives to achieve a smooth, specular finish. Surface roughness is specified in nanometres or micrometres of Ra, depending on material and application.

Typical applications include jewelry and metalwork finishing, optical component manufacturing, semiconductor wafer preparation, automotive and aerospace parts, and woodworking veneers. The choice of method and abrasive depends on material hardness, desired gloss, and dimensional tolerances.

Safety and environmental considerations include dust control, proper handling of chemical slurries, protective equipment, and waste disposal. The practice has evolved from abrasive polishing with natural stones to precision finishing using synthetic abrasives, lapping, and CMP in modern manufacturing.