Innovations in repair and fabrication of cutting tools using automated laser cladding

自2004年以来，钨的价格上涨了约300%(《经济学人》，2005年4月14日)。由于发展中国家的巨大需求(仅中国一人就使用了世界钨产量的30%以上)，以及世界上缺乏大量新的露天矿山发现，预计这种价格上涨将继续下去。高质量的WC刀具通常用于400次切割任务，然后才需要重新磨削。重磨步骤的数量取决于刀具的特性，对于为加工大批量零件而制造的特殊刀具来说，重磨步骤的数量非常有限。经过最大次数的重磨后，刀具将被报废，尽管其长度增加几毫米可以节省价值300-400美元的刀具。在许多情况下，刀具会因为制造上的小错误或小芯片的存在而报废。在这个项目中，激光熔覆被用来开发一种修复WC刀具的新技术。此外，还将研究在合金钢等非WC基材上熔覆碳化钨，以开发新型低成本WC刃口钢刀具。此外，还将研究使用激光熔覆制造金刚石和金属陶瓷工具。申请者将在该项目中使用最先进的实验室设施，包括1000W的Nd：YAG激光器、送粉器、4轴定位工作台和用于监测和控制熔覆层的视觉系统。申请的资金将主要用于支持研究生和一名博士后研究员。

The price of tungsten has gone up by about 300% since 2004 (The Economist, April 14th 2005). This increase in price is expected to continue due to a huge demand from developing countries (China alone uses more than 30% of world tungsten production) and the lack of  new opencast mines discoveries in the world. Good quality WC tools are usually used for 400 cutting tasks before they need to be resharpened. The number of resharpening steps depends on the features of the tools and it is very limited for special tools built for machining of high volume parts. After the maximum number of resharpening, the tool is scrapped although a few millimeters addition to its length can save $300-$400 worth of tool. In many cases a cutting tool is scrapped because of small manufacturing errors or the presence of small chips.   In this project, laser cladding is used to develop a new technique to repair WC cutting tools. In addition, cladding of tungsten-carbide on non-WC substrates such as alloy steel will be studied to develop new low-cost steel tools with WC cutting edges. Furthermore, fabrication of diamond and cermet tools using laser cladding will be investigated. The applicants state of the art lab facilities which include a 1000 W ND:YAG laser, powder feeders, 4-axis positioning table, and vision system for monitoring and control of  the clad will be utilized in the project. The requested funding will primarily be used to support graduate students and one post-doctoral fellow.