In Situ Characterization of Effect of Rapid Thermal Cycling During Additive Manufacturing on Deformation-Induced Transformations and Micro-Mechanical Properties

增材制造过程中快速热循环对变形引起的转变和微机械性能影响的原位表征

• 批准号: 1402978
• 负责人: Allison Beese
• 金额: $ 30万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1402978&HistoricalAwards=false
• 关键词: Situ; Characterization; Effect; Rapid; Thermal

This award supports fundamental research on additive manufacturing of metallic materials, in which the primary goal is to uncover the relationships between thermal processing cycles, microstructure, and mechanical properties in parts made through additive manufacturing. In the laser-based additive manufacturing techniques studied here, a powder feedstock material is delivered to a desired location, and a laser locally melts the powder to fuse it to the material below, building up a component one layer at a time. The thermal cycles generated by the subsequent laser passes affect the microstructure of the underlying material, and therefore the mechanical properties (e.g., strength and ductility) of the component. Here, two materials systems will be examined: a titanium alloy that undergoes diffusion-based phase transformation upon cooling, and a stainless steel alloy that undergoes diffusionless deformation-induced phase transformation upon mechanical loading. This research aims to: elucidate the effect of thermal history on the local microstructure and mechanical properties in additive manufactured materials, and develop physically based plasticity models that take into account the effect of thermal history, resulting microstructure, and microstructural evolution on the local plasticity properties.Additive manufacturing has great potential to transform U.S. manufacturing, allowing for the production of custom-designed structural components for countless applications where the cost to develop tools for forging, casting, or forming of metal components is not warranted for the small number required (e.g., replacement parts for aging Department of Defense airplanes, ships, and submarines) in an economical procedure with less waste material than traditional subtractive manufacturing. Fundamental research will lead to the development of fully integrated computational models in which the processing parameters (e.g., laser power, path, and speed) are determined to produce an end net shape component with specified mechanical properties, providing the infrastructure for a design space with practically no limitations on geometries that can be fabricated.

该奖项支持有关金属材料添加剂制造的基本研究，其中主要目标是揭示通过增材制造制造的零件中的热处理周期，微结构和机械性能之间的关系。在此处研究的基于激光的添加剂制造技术中，将粉末原料材料交付到所需的位置，而激光局部将粉末融化，将其融合到下面的材料上，一次建立一个组件一层。随后的激光通过产生的热循环会影响基础材料的微观结构，因此会影响组件的机械性能（例如强度和延展性）。在这里，将检查两种材料系统：一种在冷却后经历基于扩散的相变的钛合金，以及一种不锈钢合金，可在机械载荷时经历无扩散变形诱导的相变。这项研究的目的是：阐明热历史对添加剂制造材料中当地微观结构和机械性能的影响，并开发基于物理的可塑性模型，这些模型考虑了热历史的影响，产生的微观结构以及微结构进化对当地可塑性的影响，可以使美国的生产范围造成巨大的生产工具，从而实现了巨大的构建工具，以实现定制的构建工具，以实现定制的构建工具，以实现定制的生产效果。对于所需的少量数量（例如，国防部飞机，船只和潜艇的替换零件），不保证金属组件的锻造，铸造或形成，而造成了较少的废物，而不是传统的减法制造业。 基本研究将导致开发完全集成的计算模型，在这些计算模型中，确定处理参数（例如，激光功率，路径和速度）具有具有指定机械性能的最终净形成分，从而为设计空间提供了基础架构，实际上没有对可以制造的地理位置的限制。