PISTON COATED DIAMOND LIKE CARBON THIN FILM AND METHOD OF MANUFACTURING THE SAME WITH SCM415 MATERIAL

摘要

PURPOSE: A piston coated with a diamond-like carbon thin film using SCM415 and a method for manufacturing the same are provided to improve productivity by carburizing cost effective SCM415 materials for 1-2 hours. CONSTITUTION: A piston coated with a diamond-like carbon thin film comprises a pre-treatment process(P1,P2,P3) for the piston; subsequently a charging process for the piston into a chamber; and a thin film forming process which consists of hydrogen etching(P4), argon washing(P5), intermediate layer deposition(P6), and diamond-like carbon thin film coating(P7). The pre-treatment process comprises carburizing, ultrasonic cleaning, and acid treatment. The carburizing charges the piston into a furnace; maintains the temperature between 930 and 950°C for 30-60 minutes and subsequently cools; maintains the internal temperature of the furnace between 750 and 800°C; and supplies 10-15ml/hr,m^3 of methane or ethane for 30-40 minutes into the furnace. The ultrasonic cleaning conducts a two-step cleaning composed of primary ultrasonic cleaning using trichloroethylene and secondary ultrasonic cleaning using ethyl alcohol. The acid treatment immerses the piston into a 5% nitric acid solution for 5-10 seconds. [Reference numerals] (AA) Pre-treatment process; (BB) Thin film forming process; (P1) Carburizing; (P2) Ultrasonic cleaning; (P3) Acid treatment; (P4) Hydrogen etching; (P5) Argon washing; (P6) Intermediate layer deposition; (P7) DLC thin film coating