Surface defect elimination in microgrooving of electroless nickel phosphide plating layer by brittleness enhancement

Electroless nickel phosphide (Ni-P) plating is used to fabricate microgrooves for precision glass molding (PGM) due to its excellent mechanical properties as a mold material. To achieve a high-quality microgroove fabrication, the causes of the machining defect, like burrs on the mold surface during the microgrooving of amorphous nickel phosphide (a-Ni-P) by single-point diamond cutting, are investigated. We find that the burrs can be eliminated by increasing the brittleness of a-Ni-P, so the brittleness enhancement of the material is conducted by crystallization. Then, the machined surface and the chip morphology during cutting crystalline nickel phosphide (c-Ni-P) are analyzed and compared with that during a-Ni-P microgrooving. Through this innovation, the surface quality of the microgroove is improved with minimized burrs.