Ultrafast lasers for metal colorization in the minting industry

加拿大皇家造币厂(RCM)是硬币制造和收藏业的领先者。今天，它为许多国家的金属货币盖章，并以其强大的研究和创新而闻名世界。为了保持铸币行业的领先地位，保持其竞争优势，并吸引其他国家在其金属货币上盖章，RCM现在正在研究新的防伪功能和在硬币上生产颜色设计的新方法。最近有研究表明，超快激光可以产生表面微纳米特征，可用于新的安全特征。由于一些经济体的造假成本高达总印花价值的3%，超快激光制造的结构将使造假变得更加困难，因为激光系统的成本很高，获得的机会有限，而且操作它所需的知识也很有限。超快激光产生的表面形貌也可以用来给金属着色。可以产生随视角变化的颜色和固定的颜色，并对RCM感兴趣。为了使伪造和着色技术在工业上可行，RCM对使用冲压大规模生产硬币上的特征感兴趣。在冲压过程中，首先用激光在钢模上雕刻特征，然后用钢模冲压硬币，并将特征和产生的颜色转移到硬币上。目前有几个方面阻止RCM使用超快激光在硬币上产生安全特征和颜色，这主要是由于缺乏关于超快激光与物质相互作用的知识。为了解决这些问题，RCM对渥太华大学在超高速激光加工方面的专业知识感兴趣。RCM和渥太华大学之间拟议的合作将在激光-物质相互作用、金属方面产生新的科学知识

The Royal Canadian Mint (RCM) is a leader in the coin making and coin collection business. Today it stamps metal currencies for numerous countries and is renowned worldwide for its strong research and innovation. To remain a leader in the minting industry, to keep its competitive edge and to attract other countries to stamp their metal currencies, RCM is now looking into new anti-counterfeiting features and new ways to produce color designs on coins. It was recently shown that ultrafast lasers can produce surface micro and nanofeatures which could be used for new security features. With counterfeiting costing some economies up to 3% of the overall stamped value, ultrafast laser produced structures would make counterfeiting much more difficult due to the high cost of the laser system, its limited access and the knowledge required to operate it. Surface morphologies produced by ultrafast laser can also be used to colorize metals. Color changing with viewing angle and fixed colors can be produced and are of interest to RCM. For counterfeiting and colorizing techniques to be industrially viable, RCM is interested in large scale production of features on coins using stamping. In the stamping process, features are first engraved with the laser on a steel die which is then used to stamp coins and transfer the features and resulting colors onto the coin. There are several aspects currently preventing RCM from using ultrafast laser for producing security features and colors on coins which mainly come from a lack of knowledge on ultrafast laser-mater interactions. To solve these problems, RCM is interested in the expertise in ultrafast laser machining available at the University of Ottawa. The proposed collaboration between RCM and the University of Ottawa will result in new scientific knowledge in terms of laser-mater interactions, metal