Maskless electrochemical surface texturing for cylindrical components: new developments

The tribological performance of many cylindrical components can be improved when an array of micro-cavities, often dimples, is produced on their surface, known as surface texturing. However, the production of textured surfaces on large areas at low cost and suitable texturing time remains a challenge, which is essential for industrial application and large-scale production. Maskless electrochemical texturing (MECT) draws attention as a very promising way to produce textured surfaces for journal bearings and cylinder liners of combustion engines. In this study, we propose a new configuration for the texturing chamber used in classical MECT. A new apparatus configuration is developed, where the electrolyte flows parallel to the textured region, in order to reduce the costs involved, improve the electrolyte flow and thus the efficiency of the process. Furthermore, the use of an adhesive patterned mask is investigated as a way to create the required insulation, eliminating the need for the tool perforation process. A voltage of 12 V, with texturing times of 1, 3 and 5 min, and an inter-electrode gap of 400 μm, enabled the production of dimples for a range of 650–1000 μm in diameter and 5–25 μm in depth in low carbon steel cylindrical surfaces with good reproducibility. Preferential dissolution of the ferrite was observed, probably due to its anodic nature in relation to the cementite.