Functional Tool Surfaces with Smooth Diamond-Based Tool Coatings for the Wear-Free Forming of Aluminum Sheets

This paper addresses the unique challenges in processing aluminum materials within metal forming technology, specifically focusing on complex wear conditions involving abrasion and adhesion. A promising research approach to avoid abrasive and adhesive tool wear and reduce the friction coefficient towards aluminum alloys is the use of sufficiently smooth CVD diamond coatings. To achieve this, two approaches are considered. First, wear resistance is enhanced by using tool inserts made of carbide or a tungsten alloy, directly coated with CVD diamond. Second, the friction coefficient is selectively influenced or reduced by refining the polished CVD diamond coating through laser ablation. The study investigates the impact of these surface treatments on friction coefficients during both dry and lubricated forming processes involving the aluminum alloy EN AW-5182. Comparative analyses of various surface treatments are conducted against reference tests using diamond-like carbon (DLC)-coated tools. Through application-oriented strip drawing tests, the paper systematically examines how different surface smoothing techniques affect the coefficient of friction. This research provides valuable insights into optimizing metal forming processes for aluminum alloys through tailored surface treatments, advancing our understanding of friction dynamics in these specific manufacturing conditions.