Collaborative Research: Multi-Scale Experiments and Modeling of Nanocrystalline Diamond Coatings for Dry Machining

这项合作研究奖的目标是可靠地增长和了解纳米晶体金刚石涂层的行为，使干加工经济的切削工具。 将研究传统尺寸的工具和新颖的微尺度工具，小到人类头发的宽度。研究方法包括生长极薄的金刚石涂层，测量其摩擦性能，预测其对切削温度的影响，并在干加工工业相关铝合金时对其进行评估。 金刚石生长过程将被定制为可重复地产生均匀的金刚石膜，厚度小于一微米，具有纳米尺寸的晶粒，并且与碳化钨工具材料具有强粘附力。 金刚石薄膜的摩擦，磨损和结构特性将研究从纳米到宏观尺度，使用原子力显微镜，环境控制的摩擦，空间分辨表面光谱，和正交加工实验。 这将决定生长参数和所得涂层性质之间的关系。 将模拟由纳米晶体金刚石的低摩擦系数提供的切削工具温度降低。 涂层刀具的干加工性能将被评估用于钻削和微端铣削的铸造铝合金具有高硅含量，广泛用于运输行业。 这项研究将通过解决金属加工液的主要未解决的工业问题而造福社会。 减少或消除金属加工液在软质、耐磨金属的干式加工中的使用，将同时减少制造业的环境影响和能源消耗，从而提高经济竞争力。 纳米晶金刚石涂层是非常有前途的，因为它们的高硬度，低摩擦系数，和低附着力的工件材料，从而减少磨损，发热，和芯片堵塞，分别。 进一步的社会影响将来自于培养工程专业的学生，从代表性不足的群体中招募和留住学生，并指导他们攻读研究生课程。 这包括一名来自历史上代表性不足的群体的学生，他们将得到这个项目的支持。 将开发公共外联演示文稿，以培养初中和高中学生对科学和工程的兴趣。 大学，工业和政府实验室之间的密切合作将加强技术转让，并使学生获得更多样化的教育体验。

The objectives of this collaborative research award are to reliably grow and understand the behavior of nano-crystalline diamond coatings for cutting tools that will make dry machining economical. Tools of conventional sizes and novel micro-scale tools, as small as the width of a human hair, will be studied. The research approach involves growing extremely thin diamond coatings, measuring their friction properties, predicting their impact on cutting temperature, and evaluating them when dry machining an industrially-relevant aluminum alloy. The diamond growth process will be tailored to repeatably produce uniform diamond films, less than one-micrometer thick, with nanometer size grains, and strong adhesion to the tungsten carbide tool material. The friction, wear, and structural properties of the diamond films will be studied at from the nano- to macro-scale using atomic force microscopy, environmentally-controlled tribometry, spatially-resolved surface spectroscopy, and orthogonal machining experiments. This will determine the relationship between growth parameters and resulting coating properties. The cutting tool temperature reduction afforded by the low friction coefficient of the nano-crystalline diamond will be modeled. Dry machining performance of coated tools will be evaluated for drilling and micro end milling of a cast aluminum alloy with high silicon content that is used extensively in the transportation industry. This research will benefit society by addressing the major, unsolved industrial problem of metalworking fluids. Reducing or eliminating the use of metalworking fluids in dry machining of soft, abrasive metals, will simultaneously reduce the environmental impact and energy consumption of the manufacturing industry, resulting in improved economic competitiveness. Nano-crystalline diamond coatings are extremely promising because of their high hardness, low coefficient of friction, and low adhesion to workpiece material thus reducing wear, heat generation, and chip clogging, respectively. Further societal impact will result from training engineering students, recruiting and retaining students from underrepresented groups, and guiding them to graduate programs. This includes one student from a historically underrepresented group who will be supported by this project. Public outreach presentations will be developed to foster an interest in science and engineering among middle and high school students. The close collaboration between the universities, industry, and government lab will enhance technology transfer and expose the students to a more diverse educational experience.