Ultrafast lasers for metal colorization in the minting industry

加拿大皇家造币厂（RCM）是硬币制造和硬币收集业务的领导者。今天，它为许多国家印制金属货币，并以其强大的研究和创新而闻名于世。为了保持在铸造行业的领先地位，保持竞争优势，并吸引其他国家印制他们的金属货币，RCM现在正在研究新的防伪功能和在硬币上生产彩色设计的新方法。最近的研究表明，超快激光可以产生表面微纳米特征，这些特征可以用于新的安全特征。由于一些经济体的仿冒成本高达整体冲压价值的3%，超快激光生产的结构将使仿冒更加困难，因为激光系统的高成本，其有限的访问和操作它所需的知识。超快激光产生的表面形貌也可用于金属着色。可以产生随视角变化的颜色和固定的颜色，这是RCM感兴趣的。为了使伪造和着色技术在工业上可行，RCM对使用冲压技术大规模生产硬币的特征感兴趣。在冲压过程中，首先用激光在钢模具上雕刻特征，然后用钢模具冲压硬币，并将特征和产生的颜色转移到硬币上。目前有几个方面阻碍了RCM使用超快激光在硬币上生产安全特征和颜色，这主要是由于缺乏对超快激光-物质相互作用的了解。为了解决这些问题，RCM对渥太华大学提供的超快激光加工专业知识感兴趣。RCM和渥太华大学之间拟议的合作将在激光物质相互作用、金属等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