Raymond Machinery Co.,Ltd as s supplier of casting parts, not only can do further processing as per customers’ requirement, but also can do different kinds of surface treatment. As you know, before or after further processing, surface treatment of casting blank is necessary. Today, engineer is going to share some common surface treatment methods.
1, Shot Blasting: Small abrasive particles such as steel shot or grit are propelled at high speed onto the casting surface using compressed air or a mechanical wheel.
2, Grinding and Polishing: Grinding uses abrasive wheels to remove material from the casting surface. The abrasive grains on the wheel cut into the surface, reducing its roughness.
Polishing follows grinding and uses finer abrasives, often in a paste or liquid form, along with a soft polishing wheel. The polishing wheel rotates at a high speed, and the abrasive material smoothens the surface to a mirror – like finish.
3, Pickling: The casting is immersed in an acid solution, usually hydrochloric acid, sulfuric acid, or a mixture of acids. The acid reacts with the surface oxides and other impurities, dissolving them and leaving a clean surface.
4, Passivation: For stainless – steel castings, passivation involves immersing the part in a nitric acid or citric acid solution. This causes the formation of a thin, passive oxide layer on the surface of the stainless steel.
5, Electroplating: The casting is made the cathode in an electrolytic cell, and a metal salt solution of the plating metal (such as nickel, chromium, or zinc) is used as the electrolyte. When an electric current is passed through the cell, metal ions from the electrolyte are deposited onto the casting surface.
6, Anodizing: Primarily used for aluminum castings. The casting is made the anode in an electrolytic cell with an acid electrolyte (such as sulfuric acid). An oxide layer is formed on the aluminum surface through an electrochemical reaction.
7, Painting: Paint is applied to the casting surface using methods such as spraying, dipping, or brushing. The paint can be solvent – based or water – based and contains pigments, binders, and other additives.
8, Powder Coating: The powder coating material, which is a dry, free – flowing powder (usually a polymer resin with pigments and other additives), is electrostatically attracted to the grounded casting surface. The coated part is then cured in an oven at a specific temperature, causing the powder to melt and form a continuous, durable coating.
9, Ceramic Coating: Ceramic coatings can be applied through methods like plasma spraying or chemical vapor deposition. In plasma spraying, a ceramic powder is fed into a plasma jet, where it is melted and propelled onto the casting surface. In chemical vapor deposition, a gaseous precursor reacts on the surface to form a ceramic layer.