Effects of tribological behavior of DLC film on micro-deep drawing processes

To decrease the size effects of friction in microforming, three kinds of surface coatings, such as diamond-like carbon (DLC), TiN and MoS2, were deposited on surfaces of dies with plasma based ion implantation and deposition (PBII & D) method and magnetron sputtering technique, respectively. The tribological behavior of surface coatings was analyzed considering plastic deformation of specimen at contact interface. The analyses indicate that there is a lower coefficient of friction (COF) and a high wear resistance under the condition of large strain/stress when using the DLC film. The graphitization of DLC film occurs after 100 times of tests. The mechanism of graphitization was analyzed considering energy induced by friction work. The effects of DLC film properties on qualities of micro-deep drawn parts were investigated by analyzing the reduction of wall thickness, etc. The results indicate that DLC film is very helpful for improving the qualities of the micro-parts.