Plasma-nitriding assisted micro-texturing into stainless steel molds

Micro-texturing has grown up to be one of the most promising proceduresThis related application required for large-area, fine micro-texturing onto the stainless steel mold materialsA new method other than laser-machining, micro-milling or micro-EDM was awaited for further advancement of this micro-texturingIn the present paper, a plasma nitriding assisted micro-texturing was developed to make various kinds of micro-patterns onto the martensitic stainless steelsFirst, original patterns were printed onto the surface of substrate by using the ink-jet printerThen, the masked substrate was subjected to high density plasma nitriding; the un-masked surfaces were nitrided to have higher hardnessThis nitrided substrate was further treated by sand-blasting to selectively dig the soft, masked surfacesFinally, the micro-patterned martensitic stainless steel substrate was fabricated as a mold to duplicate these micro-patterns onto the work materialsThe spatial resolution and depth profile controllability of this plasma nitriding assisted micro-texturing was investigated for variety of initial micro-patternsThe original size and dimension of initial micro-patterns were precisely compared with the three dimensional geometry of micro-textures after blasting treatmentThe plastic cover case for smart cellular phones was employed to demonstrate how useful this processing is in practice.