Direct In Situ Analysis of Surface Flow Fields in Deformation Processing of Lightweight Structural Metals

铝、镁和钛的轻质结构合金在离散产品领域的应用中具有技术意义，包括汽车、航空航天、能源系统和生物医学应用。在制造过程中，通常使用诸如挤压、轧制、金属板加工和成形方法的变形工艺来使来自这些金属系统的部件成形。由工艺产生的部件的表面质量属性，例如缺陷、光洁度和强度，在很大程度上取决于表面处金属流动的性质。这种表面流动在控制成形界面处的摩擦和磨损方面也起着重要作用。由于这些原因，迫切需要研究变形加工中流动的基本性质，以便通过适当控制流动来提高部件和产品质量。该奖项将通过支持研究来满足这一需求，以推进关键工业领域最先进的制造工艺技术。补充研究是一个教育计划，涉及本科研究人员在创建一个视频画廊的流动，为行业，并适度侧重于培养创业精神的研究生学习。这项研究将研究一个模型过程系统-一个硬模（楔）对工件滑动-与三个协调的推力。 首先，变形科学倡议将利用现场观测技术对工件表面和接触处的流动进行高分辨率分析。流动现象（例如，层流、弯曲、不稳定性）、应变和应变率场，将作为可控工艺参数的函数进行分析。将探讨流动类型、摩擦和缺陷形成之间的相互作用。其次，工件表面质量将从微观结构、缺陷结构、机械性能和形貌方面进行检查。表面质量属性将与流场相关。第三，表面流将使用连续的方法，结合材料的异质性和颗粒级结构建模。通过整合分析结果，将创建一个加工图，根据关键材料和工艺参数划分流动和缺陷。该研究将专门针对铝、镁和钛的低密度结构合金模型进行，选择这些合金是因为它们的实验适用性和与离散产品部门的减重直接相关性。这些技术和发现将影响材料加工、摩擦学、塑性和地球物理折叠现象等不同领域。

Light-weight structural alloys of aluminum, magnesium and titanium are of technological interest for use in applications in the discrete products sector, encompassing automotive, aerospace, energy systems and biomedical applications. Deformation processes such as extrusion, rolling, sheet-metal working, and forming methods are typically used to shape components from these metallic systems during manufacturing. The surface quality attributes of components, such as defects, finish and strength, created by the processes is to a large extent determined by the nature of metal flow at the surface. This surface flow also plays a major role in controlling friction and wear at the forming interfaces. For these reasons, there is a critical need for studying the fundamental nature of the flow in deformation processing so that component and product quality can be enhanced by suitable control of the flow. This award will address this need by supporting research to advancing the state-of-the-art of manufacturing process technologies in key industrial sectors. Complementing the research is an education program involving undergraduate researchers in creating a video gallery of flows for industry, and a modest focus on fostering entrepreneurship in graduate study. The research will study a model process system - a hard die (wedge) sliding against a workpiece - with three coordinated thrusts. Firstly, a deformation science initiative will utilize in situ observational techniques for high-resolution analysis of flow at workpiece surfaces and contacts. Flow phenomena (e.g., laminar, sinuous, instabilities), strain and strain rate fields, at the surfaces will be analyzed as a function of controllable process parameters. The interplay between flow type, friction, and defect formation will be explored. Secondly, workpiece surface quality will be examined in terms of microstructure, defect structures, mechanical properties, and topography. The surface quality attributes will be correlated with the flow fields. Thirdly, surface flow will be modeled using continuum approaches that incorporate material heterogeneity and grain level structure. By integrating the analyses results, a processing map, that demarcates flows and defects in terms of key material and process parameters, will be created. The study will be conducted specifically on model low-density structural alloys of aluminum, magnesium and titanium, selected for their experimental suitability and direct relevance to weight reduction in the discrete products sector. The techniques and findings will impact areas as diverse as materials processing, tribology, plasticity, and geophysical folding phenomena.