Development of efficient and scalable ultrasound-assisted solidification technologies for manufacturing advanced metallic alloys (Ultra-Cast)

本建议书是为响应2013年7月9日开幕的EPSRC制造研究员主导研究项目的未来号召而提出的。本建议书旨在解决金属材料和制造业迫切需要寻找和采用下一代阶跃变化技术，以制造机械性能和可靠性大大提高、能耗更低且对环境有负面影响的原生锭和/或成形部件，例如用于大众运输应用的铝和镁合金、消费产品、用于工业燃气轮机(IGT)的镍高温合金用于发电。目前，我们的经济竞争对手正在这一领域进行广泛的研究。通过采用更轻的合金，具有更好的机械性能和可靠性，大众运输系统可以减少能源消耗，减少对环境的不利影响，使替代燃料方案的更广泛应用成为可能。而随着材料性能的改善，IGT可以在更高的温度占空比下运行，以提高发电效率。铸造是这些和其他应用中应用最广泛和最多产的制造技术之一。超声波空化处理为传统和先进金属材料的熔融加工和铸造提供了可持续、经济和无污染的解决方案，并显著改善了所制造产品的机械性能和质量。虽然超声辅助铸造技术已经在实验室中得到了验证，但目前还没有得到广泛的工业应用，这主要是由于对导致宏观/微观组织改善的机制，特别是对凝固过程不同阶段促进形核和晶体增殖的机制缺乏深入的了解。该计划将研究金属合金在超声波作用下的凝固基本原理，并开发可用于工业开发的方法，以控制和优化在超声波影响下的凝固微结构。其目标是通过组织细化、提高化学和显微组织的均匀性以及减少原锭和成形铸件中的凝固缺陷，实现铸造产品中材料性能的显著改善。提出的研究是雄心勃勃和具有挑战性的，其目标不仅是研究金属合金凝固不同阶段的基本机制，而且建立实用的方法，利用超声波促进金属合金凝固不同阶段的晶粒形核和增殖。这项研究的新奇之处在于结合了最先进的现场超高速成像研究，以及对真实金属合金进行的先进的数值建模和放大实验。其成果将是新的知识和新的技术指南，并使用EPSRC液态金属工程创新制造中心(LIME)及其行业合作伙伴唐卡斯特集团有限公司的中试和工业规模设施生产的商业合金和铸件证明其有效性，为行业提供使用超声波技术控制铸件微观结构的知识、方法和工具。

This proposal is submitted in response to the EPSRC Manufacturing the Future Call for Investigator-led Research Projects open on 09 July 2013.This proposal addresses the urgent need of the metal materials and manufacture industry to search and adopt next-generation, step-change technologies for the manufacturing of primary ingots and/or shaped components with much improved mechanical properties and reliability, less energy consumption and negative environmental impact, e.g. Al and Mg alloys for mass transport applications, consumer products, Ni superalloy for industrial gas turbines (IGTs) for energy generation. At present, our economic competitors are conducting extensive research in this area. By adopting lighter alloys with better mechanical properties and reliability, mass transport systems can reduce energy consumption, adverse environmental impact, making wider application of alternative fuel schemes possible. While with improved materials performance, IGTs can be operated at a higher temperature duty cycle to increase the efficiency of energy generation. Casting is one of the most widely used and productive manufacturing technologies for these and other applications. Ultrasonic cavitation treatment offers sustainable, economical and pollution-free solutions to melt processing and casting of conventional and advanced metallic materials with significant improvement in mechanical properties and quality of the products manufactured. Although demonstrated on a laboratory scale, the ultrasound-assisted casting technique has not yet found widespread industrial application, mostly due to the lack of in-depth understanding of the mechanisms that lead to the macro/microstructure improvement, especially on the mechanisms of enhancing nucleation and crystal multiplication at different stages of solidification processes. The proposed programme will study the solidification fundamentals of metallic alloys under applied ultrasonic waves, and develop industrial exploitable methodologies to control and optimise the solidified microstructure under the influence of ultrasonic waves. The goal is to realise distinct materials performance improvements in cast products through microstructure refinement, increased chemical and microstructural homogeneity and the reduction of solidification defects in primary ingots and shaped castings. The proposed research is ambitious and challenging, aiming to study not only the fundamental mechanisms but also to establish practical methodologies of using ultrasound to promote grain nucleation and multiplication during different stages of solidification in metallic alloys. The novelty of the research is a combination of state-of-the-art in-situ ultra-high speed imaging studies plus advanced numerical modelling and scale-up experiments performed on real metallic alloys. The outcomes will be new knowledge and novel technological guidelines with their validity demonstrated using commercial alloys and castings produced in the pilot and industrial-scale facilities of the EPSRC Innovative Manufacturing Centre in Liquid Metal Engineering (LiME) and industry partner, Doncasters Group Ltd, providing industry with the knowledge, methodologies and tools to control microstructure of castings using ultrasound technology.