finishers for metals Flashcards
what type of finishes for metals are there electroplating
polymer dip coating
galvanising
poeder coating
anodising
what is electroplating
coat one metal with a different type of metal
what is the benefit of electroplating
improve aesthetic
what is the common base metal of electroplating
can be copper, silver and other metals
what is the common coat metal for electroplating
chromium
silver
gold
what is steel commonly plated with
tin
nickel
chronium
cadmium
why do we plated steel
improve corrision wear resistent
what can polymer dip coating be
liquid / powder form
what form is the plastic in polymer dip coating
liquid form of pvc known as plastisol
what happens to be the metal parts in polymer dip coating
pre-heated before being dipped
what happens when powder is used in polymer dip coating
it is in a fluidised tank
air is blown into the bottom of the tank which makes the powedered plastic appear to bubble
what is the process of galvanising q
steel is immersed into a molten bath of zinc
this creates a metalkirgical bond between the zinc and the steel making a verry effectve…..
what metal is used in galvanising
steel
what liquid is used in galvalising
zinc
what does powder coating involve
involves the use of electrostatic charge
what happens in powder coating
the powder is positively charged. the object to be coated in negatively charged
the charge is sprayed onto the surface. the electrostatic charge means that it sticks evenly
it is then put into an oven, where the coating melts and forms a smooth, hardwearing surface
what does anodising use
electrolysis
what is anodising used on
aluminium and titanium - not steel
what does the process create in anodising
creates an oxide layer that makes the surface smooth and protects from corrosion
how does anodising work
the product is placed in a solution of sulphuric acid, sodium sulpate and water
the oxide layer is also to accept dyes of a variety of colours
