Zinc Phosphate (Z-type)
Color: Light gray-dark gray
(As the amount of carbon in the metal to be treated increases, the particle size decreases and the color becomes darker.)
■ Treatment method: ① Spray type: 1-10 g/㎡ film weight possible
② Sedimentation type: 1.5-49 g/㎡ film weight possible
■ Characteristics: ① High corrosion resistance, hygroscopicity, and adhesion
② In Korea, more than 90% are used
■ Use: For undercoat, cold forming, abrasion resistance, corrosion resistance
Manganese phosphate (M type)
Color: blackish brown
(According to the amount of MnO2 in the film, the brown color becomes darker. Normally, it is used by adsorbing oil, so the oil reinforces the black color and becomes black.)
■ Treatment method: Only precipitation type is possible, and the weight of the film is 5-30 g/㎡.
■ Characteristics: ① A film made of fine particles is required.
② Mn-based coatings have a higher processing cost than Zn-based coatings, but thicker coatings are possible.
■ Use: Improve abrasion resistance