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First, mechanical surface treatment: polishing, sandblasting, spraying, drawing, batching, knurling. . . . . .

Second, chemical surface treatment: pickling, over-alkali, blue-blackening, chemical oxidation. . . . . .

Third, electrochemical surface treatment: anodizing, electroplating. . . . . .

Fourth, modern surface treatment: laser laser engraving, ion plating. . . . . .