Wear behaviour of TiAlN/DLC coating in milling of AMPCOLOY®83

With the development of new manufacturing technologies and the consequent exponential growth of the machining industry, there was a need for improvements in cutting tools, especially when it comes to improving their performance in the process. Thus, it is possible to verify the development of thin coatings that allow extending the life of cutting tools. The DLC - Diamond-like carbon system is one type of thin coating that promotes low friction and solid lubrication. In addition, TiAlN coatings promote good oxidation resistance and high machining speed. Thus, this work aims to evaluate the wear behavior of a multilayer coating (TiAlN/DLC) during the milling of a Copper-Beryllium alloy commercially designated as AMPCOLOY®83. The quality of the machined surface was evaluated, and the wear of the cutting tool was studied. The results were compared with uncoated tools. The coating was characterized by its thickness, structure, chemical composition, morphology, mechanical properties, and adhesion to the substrate. Machining tests were performed by varying the cutting length. The reference cutting parameters were chosen according to the manufacturer’s instructions. It was found that the coated tools presented better performance than the uncoated tools, both in machined surface roughness and wear resistance. Regarding the main wear mechanisms of the uncoated cutting tools, adhesion, crater formation, and cutting-edge breakage were observed. Regarding the coated tools, the main mechanism observed was coating delamination, however, adhesion and cutting-edge breakage were also identified.