Impact of continuous lubricating roller-ball tool on forming characteristics in incremental sheet forming with heat-assistance

Heat-assisted incremental sheet forming (Ha-ISF) enhances formability and enables the creation of intricate structures. Major challenges in incremental sheet forming (ISF) are achieving a good surface finish, maintaining geometrical accuracy, minimizing tool wear, and optimal energy consumption. The present research investigates the performance of continuous lubrication with a roller-ball tool in ISF and Ha-ISF, comparing its effectiveness with a conventional tool. The work also examines the effect on pre-heat-treated sheets at 290 °C. The primary focus was on assessing the impact of continuous lubrication on formability, surface quality, and geometrical accuracy throughout the forming process. The continuous lubricating rolling-ball tip tool (RBT) guarantees a constant flow of lubricant throughout the forming process. Numerous factors, including material flow, forming forces, and tool wear, were examined experimentally for both types of tools. The results show that the continuous lubricating roller ball tool significantly enhances material flow, minimizes surface roughness, and decreases tool wear. About 80% improvement in surface roughness and a 34% decrease in forming forces are reported with RBT in the case of Ha-ISF. Additionally, the lower thickness variation is observed for Ha-ISF with RBT. The present analysis offers valuable insights into enhancing the process capabilities of Ha-ISF, emphasizing the importance of tool design and lubrication methods in achieving superior outcomes.