A New Strategy for the Design of Wear Resistant Nitride Coatings for Dry Machining

该奖项的研究目标是研究切削刀具涂层的新概念，该概念将使钢和其他难以切削的金属合金的干式高速加工成为可能。该方法是设计耐高温氧化和扩散磨损机制的涂层。目前最先进的涂料主要基于其抗氧化性而得到推广。使用在待加工工件中具有有限溶解度的大型金属氮化物化合物来抵抗基于扩散的磨损机制。由于高速加工过程会受到氧化和扩散磨损的影响，因此将研究由大型金属氮化物和抗氧化氮化物交替层构成的多层涂层。将这些涂层作为纳米级多层沉积也将提高涂层的硬度和抗断裂性能。溅射沉积和沉积涂层的全面化学和机械特性也将进行。研究将评估这些涂层在高速车削钢时的性能。该研究的社会效益将通过推广干式加工来代替润滑加工来实现。使用切削液的加工操作引起了环境和健康问题。切削液的处理变得更加规范，因此对金属切削工业来说成本更高。在本研究中测试的涂层的成功将大大减少润滑剂的使用量，在某些情况下，在切割过程中完全消除切削液。

The research objective of this award is to investigate a new concept in coatings for cutting tools that will enable dry, high-speed machining of steels and other hard-to-cut metal alloys. The approach is to design coatings that are resistant to both high-temperature oxidation and diffusion-based wear mechanisms. Current state-of-the art coatings have been promoted based primarily on their oxidation resistance. Resistance to diffusion-based wear mechanisms will be achieved using large-metal nitride compounds that have a limited solubility within the work piece to be machined. Since high-speed machining operations are subject to both oxidative and diffusion wear, multilayer coatings that are structured as alternating layers of large-metal nitrides with oxidation-resistant nitrides will be investigated. Depositing these coatings as nano-scale multilayers will also enhance the hardness and fracture resistance of the coatings. Sputter deposition and full chemical and mechanical characterization of the deposited coatings also will be carried out. Research will be conducted to evaluate the performance of these coatings during high-speed turning of steel. The societal benefits of the research will be realized through the promotion of dry machining in place of lubricated machining. Both environmental and health concerns have been raised for machining operations that use cutting fluids. The disposal of cutting fluids has become more regulated and therefore more costly for the metal cutting industry. The success of the coatings to be examined in this study will enable a substantial reduction in the quantity of lubricant used, and in some cases complete elimination of cutting fluids during cutting.