Advances in metal cutting tool materials

The dominant tool material for metal cutting with tooling using indexable inserts is the coated cemented carbide. There is currently a strong development in coating technology for carbide inserts and most modern metal cutting grades are manufactured with multi-layer coatings to give optimum wear reduction in the intended application area of each grade. The development of new coating processes has led to new requirements on the underlying carbide in order to utilize the full potential of the coating. As a result, there is also a strong development in cemented carbide technology for metal cutting applications, frequently including the formation of surface gradient structures. In modern metal cutting grades, the coating and substrate have been tailored to each other and carefully optimized for the intended application area together with insert macro-and micro-geometry. Using this type of application-oriented approach, it is possible to further improve the performance of modern tool materials in machining. In spite of the significantly improved performance of the modern coated carbide grades, there is still a strong growth in other high-performance tool materials such as cermets, ceramics, cubic boron nitride and diamond. Coating development has also become important for these materials and new cermet and ceramic grades with coatings have been successfully introduced during the last 5 years. In addition, 2 completely new tool material concepts, diamond coating by a plasma CVD process and multi-corner inserts technology for cBN inserts, have recently been introduced on the market. However, further developments in tool materials will be required to meet the future needs of the manufacturing industry, including demanding applications such as hard part machining, high productivity machining, dry machining, superfinishing and new difficult-to-machine work materials.