Exploring the Effectiveness of a Complex Coating Technique for Use the Smallest Parts of Advanced Powertrain Fuel System

Abstract

The objective is to develop the complex coating technique with high quality and homogeneity of coating for spherical parts with diameter of 2 ∼ 4 mm and stable mass production shall be secured with consideration of coating material, process and jig design. Silicon oxide-diamond like carbon (SiO-DLC) complex coating chemistry is expected to enhance the high temperature stability as opposed to DLC. Currently, the spherical part is first welded and then assembled with other parts, finally they are coated with DLC. However in this manner, the maximum charging in one coating batch is limited due to the very big size of the whole component which increases cost. Therefore the spherical part is to be coated before welding. Overall, reactive sputtering with high precision fixturing and masking technique resulted in the best overall properties for modern powertrain fuel system. The jig design was optimized with consideration of coating properties (height, width, thickness, inserting distance) and spherical parts were fixed at the jig with magnet plate. Coating material and process were determined with several trials. In conclusion the PVD+PACVD coated parts is developed and coatings with high quality, homogeneity and 30,000 inserting amount are secured. Coated parts are minimum 100 % more durable than non-coated parts.