Phenomenological studies on solidification and casting of aluminum and magnesium alloys

铝镁合金凝固铸造唯象研究

• 批准号: RGPIN-2014-04852
• 负责人: Ravindran, Comondore
• 金额: $ 1.46万
• 依托单位: Ryerson University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=638176
• 关键词: Phenomenological; studies; solidification; casting; aluminum

Weight reduction, enhanced fuel efficiency (2025 CAFE: 65.4 MPG), energy conservation, reduced carbon emissions and recycling have become cornerstones for a prosperous global economy and high quality of life. Light alloys of aluminum (density: 2.70 g/cm3) and magnesium (density: 1.74 g/cm3) hold much hope, and provide scope for the development of novel manufacturing processes for the automotive sector. However, there are still some challenges impeding the increased use of these alloys, because they are particularly prone to forming casting defects (e.g., inclusions, porosity, hot tearing, misruns, distortion) during solidification. There is also a need to improve the high temperature performance of aluminum alloys used in engine systems (e.g., engine blocks, cylinder heads) with improved operating efficiency. For magnesium alloys, specific needs include the development of new grain refiners for enhanced strength and castability.This research program seeks to build upon extensive research experience, knowledge and success in castability and characterization of aluminum and magnesium alloys. It envisages a deeper understanding of solidification mechanisms, with a view to reducing the formation of casting defects and improving the mechanical properties of aluminum and magnesium alloys.A new methodology, based on neutron diffraction analysis, will be used to characterize the formation of defects in aluminum and magnesium alloys, specifically for relating the microstructure, strain/stress and hot tear formation. In-situ and ex-situ neutron diffraction will be used for dynamic monitoring of solid fractions of phases and for residual strain/stress mapping. Commercial software will be utilized for modeling heat transfer, hot spots, heat flow, fluid flow and hot tearing in conjunction with neutron analyses and microstructural characterization. The fundamental knowledge gained from both the modeling and the laboratory experiments will be used to explain and predict the formation of casting defects with a view to transferring the knowledge on an industrial scale for foundry and in-service automotive applications. For aluminum alloys, a systematic study relating solidification conditions, heat treatment procedures, mechanical properties and residual strain/stress will be carried out, with a view to eliminating distortions in castings. Novel magnesium grain refiners will be synthesized with appropriate ball milling and sintering for the development of high performance castings. The program will reinforce and enhance an excellent track record of HQP training.The impact of this research will be felt in the 3Es: Energy, environment and economy. Elimination of fuel leakage, increased operating efficiency and extension to new technologies (e.g. linerless engine blocks) will result in increased lightweighting, directly impacting conservation of energy and reducing greenhouse gas emissions. Overall, these advances will reduce recalls (via elimination of distortion) and significantly decreased scrap rate of castings (thru elimination of hot tearing) ensuring enhanced profitability for the Canadian automotive industry, contributing to the revival of the auto economy. As a consequence, they will significantly help in developing standards, policies and overall vision for automobile weights and related emission levels.

减轻体重、提高燃油效率(2025年CAFE：65.4MPG)、节能、减少碳排放和回收利用已成为全球经济繁荣和高生活质量的基石。铝(密度：2.70克/厘米~3)和镁(密度：1.74克/厘米~3)的轻合金很有希望，并为汽车行业开发新的制造工艺提供了空间。然而，由于这些合金在凝固过程中特别容易形成铸造缺陷(如夹杂物、气孔、热撕裂、脱模、变形)，因此仍有一些挑战阻碍了这些合金的广泛使用。还需要改善发动机系统(例如，发动机机体、气缸盖)中使用的铝合金的高温性能，以提高运行效率。对于镁合金，具体需求包括开发新的细化剂以增强强度和铸造性。该研究计划寻求建立在铝和镁合金的铸造性和表征方面的广泛研究经验、知识和成功的基础上。为了减少铸造缺陷的形成，提高铝镁合金的力学性能，将采用一种基于中子衍射分析的新方法来表征铝镁合金中缺陷的形成，特别是将微观组织、应变/应力和热裂形成联系起来。原位和非原位中子衍射将用于动态监测相的固相分数和残余应变/应力图。商业软件将用于模拟热传递、热点、热流、流体流动和热撕裂，并结合中子分析和微观结构表征。从建模和实验室实验中获得的基本知识将用于解释和预测铸造缺陷的形成，以期将这些知识转移到工业规模的铸造和在役汽车应用中。对于铝合金，将进行一项关于凝固条件、热处理程序、机械性能和残余应变/应力的系统研究，以期消除铸件中的变形。为开发高性能铸件，应通过适当的球磨和烧结工艺合成新型镁合金细化剂。该计划将加强和提高HQP培训的良好记录。这项研究的影响将在3E：能源、环境和经济中感受到。燃料泄漏的消除、运行效率的提高和新技术的推广(例如无衬里发动机机体)将导致更轻的重量，直接影响能源节约和减少温室气体排放。总体而言，这些进步将减少召回(通过消除变形)和显著降低铸件的废品率(通过消除热撕裂)，确保提高加拿大汽车行业的盈利能力，为汽车经济的复苏做出贡献。因此，它们将极大地帮助制定汽车重量和相关排放水平的标准、政策和总体愿景。