Plate
With plating process is known from the metal working and textile technology, in which a less noble material (metal or fabric) mechanically (not galvanically is) covered with another more noble material.
Another term for this process is derived from the connection doublé ( gold plating: gold mechanically applied to brass , not gold-plated ): doubling (also doubling ).
Plating in metalworking
In metalworking, plating is the name given to the application of one or more metal plating (s) on one or two sides to another base metal. A connection (" plaque ") that is as insoluble as possible should be created. The inseparable connection is achieved by pressure and / or temperature or subsequent heat treatment (e.g. diffusion annealing). Possible connections are e.g. B. Copper on steel and silver or gold on brass (doublé).
This is achieved through a wide variety of techniques, e.g. B. by rolling thin metal foils, welding on , casting ( ion plating ), dipping, explosive plating or by electroplating processes ( electroplating ). According to the current state of production technology (beginning of the 21st century), this is usually done using the method of roll weld cladding .
With the coating, corrosion protection, a higher surface hardness, better sliding properties or a more pleasing appearance can be achieved.
Roll weld cladding
One possibility is to wrap the base and plating material in thin button sheets, heat them and then roll them out. The button plates are removed by pickling. Another possibility is to wrap the plate with the cladding material, heat it and roll it out under high rolling pressure . It is common to roll clad aluminum alloys (base material) with pure aluminum (cladding material) and steel (base material) with stainless steel or copper or nickel or aluminum (cladding material). Containers in the chemical industry are lined with weld cladding (welding of the coating material).
Clad sheets
Clad sheets are composite materials that consist of a base material and at least one layer of another material . The cladding layers can be applied to the carrier material on one or both sides. Most of the time, the base material consists of “cheap” carbon steel , which has the strength required for use. Blasting and / or hot rolling can be used as the manufacturing process. Clad sheets offer an economical solution for applications where e.g. B. the statics requires thick-walled components, but a relatively thin cladding layer is sufficient.
Plating in textile technology
In textile technology , the term refers to a thread system that covers another, in knitting by a special type of loop formation and in spinning by spinning a cotton core thread with silk or wool yarn .
Doubling in painting restoration
Doubling is used as a prophylactic protection against painting destruction and can be traced back to the 17th century . The painting canvas is glued behind with elastic, textile material for stabilization. A painting is relined when the textile image carrier is no longer able to stabilize the layers of color in the image. Graphics made of paper can also be saved from deterioration in this way. This technique is used in restoration to stabilize an unstable canvas, to close cracks and holes and to obtain a smoother surface.
See also: marouflage