Next-Generation Sustainable Lightweight Fatigue-Critical Components Research

二十年来，运输车辆结构发生了革命性的变化，轻量化以满足更好的燃油经济性的需求。尽管在结构部件中引入铝合金取得了进展，但轻量化的尝试仍然无法满足严格的燃油效率目标。为了在车身结构中最大限度地使用轻质材料，最近出现了多材料轻质车辆架构的概念。这一概念要求在所使用的位置使用最轻的材料和最佳的性能。 * 镁合金比钢轻75%，比铝轻35%，表现出优异的疲劳性能，使其成为疲劳关键部件的可行替代品，疲劳强度是其关键性能指标的部件，如汽车中的发动机支架或飞机中的机翼-机身连接耳。与目前用于类似部件的A356或AA 6082等铝合金相比，ZK 60等镁合金的疲劳性能优于铝合金。然而，在当前的文献中，在解决镁合金的这种应用的可行性方面存在重大的科学差距。拟议研究的目标是开发知识库，并使镁合金应用于运输车辆的疲劳关键部件的技术，最终目标是设计下一代可持续的轻量化部件。* 由于其上级比强度，变形镁合金是承载部件的更佳候选材料。然而，除了由HCP微结构继承的屈服不对称性之外，它们还显示出由制造过程中涉及的严重塑性变形引起的方向各向异性。本研究将探讨新型变形镁合金在多轴疲劳载荷下不同方向的循环行为，并建立相应的设计模型。 * 拟议的研究是首次研究最轻的结构金属对下一代疲劳关键部件的适用性。从铸铁到钢冲压的过渡，以及从钢冲压到铝合金的过渡都需要近二十年的时间。预计从目前的铝合金到下一代轻质对应物的过渡也需要大约相同的时间。因此，拟议的研究是正确的时机，以开发下一代组件所需的知识和技术，这些组件预计将在未来十年内上市，以按时实现目标燃油效率。由于运输车辆制造业占加拿大贸易的30%，预计通过拟议研究开发的创新将确保加拿大在未来市场上保持竞争力。

There has been a two decade-long revolutionary changes in transportation vehicle structure light-weighting to address the need for better fuel economy. Despite the progress made by introducing aluminum alloys into structural components, light-weighting attempts still fall short to meet the drastic fuel efficiency targets. To maximize the use of lightweight materials in the vehicle body structure, a recent concept of multi-material lightweight vehicle architecture has emerged. This concept calls for the use of the lightest material with the best performance in the location used. ***Being 75% lighter than steel and 35% lighter than aluminum, magnesium alloys have shown an excellent fatigue performance that nominates them as a viable replacement for fatigue-critical components, components with fatigue strength as their key performance indicator like the engine cradle in a car, or the wing-fuselage attachment lugs in airplanes. When compared to aluminum alloys like A356 or AA6082 currently employed in similar components, magnesium alloys like ZK60 outperform aluminum fatigue behavior. However, there is a major scientific gap in the current literature in addressing the feasibility of such applications for magnesium alloys. The objective of the proposed research is to develop knowledge base, and enabling technologies for the application of magnesium alloys to fatigue-critical parts of transportation vehicles with the ultimate goal of designing next-generation sustainable lightweight components. ***Due to their superior specific strength, wrought magnesium alloys are better candidates for load-bearing components. However, beside the yield asymmetry inherited by HCP micro structure, they show directional anisotropy induced by the severe plastic deformation involved in their manufacturing process. The cyclic behavior of newly developed wrought magnesium alloys in different directions under multi-axial fatigue loading will be studied and the enabling design models will be developed in this research. ***The proposed research is a first of its kind in examining the suitability of the lightest structural metal for next-generation fatigue-critical components. The transition from cast iron to steel stamping; and steel stamping to aluminum alloys each required nearly two decades. It is expected that the transition from current aluminum alloys to next-generation lightweight counterparts will also require about the same time. Therefore, the proposed research is right in timing to develop the knowledge and enabling technologies required for the next-generation components that are expected to become market-ready in the next decade to address the targeted fuel efficiency on time. With transportation vehicle manufacturing accounting for 30% of Canada's trade it is expected that the innovation developed through the proposed research ensure that Canada remains competitive in the future market.