(1) Physical surface treatment: sandblasting, wire drawing, shot blasting, polishing, rolling, brushing, spraying, painting,
powder spraying, silk screen printing, pad printing, water transfer printing, electrophoresis, etc. (2) Chemical surface treatment: bluish blackening, phosphating, pickling, electroless plating, TD treatment, QPQ treatment,
carburizing, nitriding, chemical oxidation, passivation, etc.
(3) Electrochemical surface treatment: anodic oxidation, hard anodic oxidation, electrolytic polishing, electroplating, etc.
(4) Modern surface treatment: chemical vapor deposition (CVD), physical vapor deposition (PVD), ion implantation, ion plating,laser surface treatment, etc.