CAREER: Hierarchical Structure Integrity of Magnesium Alloys via Asynchronous Laser and Additive Processing

职业：通过异步激光和增材加工实现镁合金的层次结构完整性

• 批准号: 1846478
• 负责人: Michael Sealy
• 金额: $ 50万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1846478&HistoricalAwards=false
• 关键词: CAREER; Hierarchical; Structure; Integrity; Magnesium

Current commercially available metallic orthopedic implants are permanent and often result in complications that require costly secondary removal or repair surgeries. A potential solution is dissolvable, biodegradable magnesium alloy implants that maintain sufficient mechanical integrity long enough for the factored bone to heal, and then dissolve thus eliminating the need for any further surgical intervention. The fundamental challenge in achieving this is to slow down and control the dissolution rate of magnesium alloys within the body. This Faculty Early Career Development (CAREER) Program award seeks to address this by applying laser peening, a local deformation process that induces favorable compressive stresses and reduces corrosion rates, to the entire material volume and not just its surface as conventionally undertaken. This will be done by implementing laser peening at intermediate stages during additive manufacturing, a process that builds parts in a layer by layer manner. If successful this project will result in new manufacturing knowledge on printing defined mechanical properties in metallic materials that is extendable beyond magnesium alloys, and thus can provide the US manufacturing base with new capabilities to strengthen their competitiveness. Educational components of the award that will increase future workforce preparedness include: (1) encouraging U.S. students' pursuit of advanced degrees in manufacturing, especially from underrepresented groups in STEM; (2) promoting entrepreneurship training and commercialization of fundamental additive manufacturing research through an engineering startup competition and participation in the NSF I-Corps Program; and (3) provide a pathway to employment for credentialed students through academic apprenticeships in additive manufacturing. Further, leveraging this project with the University's established outreach program with Navajo Technical University will better position Dine students to pursue research-oriented careers and start businesses that remain on tribal lands.The technical goal of this project is isolate how strengthening mechanisms and residual stress caused by interspersing peened layers (i.e., barrier layers) inhibit dislocation motion and affect stress-corrosion behavior. The approach applies laser peening on multiple layers during printing to form an aggregate surface integrity throughout the entire build volume as opposed to a traditional external surface modification. Central to this goal is to understand how thermal inputs (from depositing the next layer of material), and mechanical inputs (from later peening stages) affect the favorable compressive stress profile induced by earlier peening steps. This will be achieved by 1) quantification of dislocation densities resulting from work hardening, grain refinement, and residual stresses, 2) verification of magnesium alloy strength and ductility resulting from varied spatial treatment frequencies, and 3) verification of increased stress-corrosion resistance. This will result in a new mathematical model to predict how frequently to asynchronously print and peen a magnesium target to mitigate thermal and mechanical cancellation of previous peening steps.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

当前的市售金属骨科植入物是永久性的，通常会导致需要昂贵的次要去除或修复手术的并发症。潜在的溶液是可溶解的，可生物降解的镁合金植入物，它们保持足够的机械完整性足够长，足以使骨骼愈合然后溶解，从而消除了对任何进一步的手术干预的需求。 实现这一目标的基本挑战是减慢并控制体内镁合金的溶解速率。这项教师早期职业发展（职业）计划奖通过应用激光佩宁（激光佩宁）来解决这一问题，这是一个局部变形过程，可诱导有利的压缩应力并降低腐蚀率，从而降低整个材料量，而不仅仅是其经常进行的表面。这将通过在添加剂制造过程中的中间阶段在中间阶段实现激光剥离来完成，该过程以一层方式构建零件。如果成功，该项目将导致有关金属材料中定义的机械性能的新制造知识，这些知识可扩展到镁合金之外，从而为美国制造基地提供新的功能，以增强其竞争力。 该奖项的教育组成部分将增加未来的劳动力准备，包括：（1）鼓励美国学生追求制造业高级学位，尤其是来自STEM中代表性不足的团体； （2）通过工程创业竞赛和参与NSF I-Corps计划促进基本增材制造研究的创业培训和商业化； （3）通过添加剂制造业的学徒制为有资格的学生提供就业的途径。此外，通过大学与纳瓦霍技术大学的既定外展计划来利用该项目，将更好地定位用餐学生从事以研究为导向的职业，并创办保留在部落土地上的业务。该项目的技术目标是隔离如何造成增强机制和残留压力通过散布剥离层（即屏障层）抑制脱位运动并影响应力腐败行为。该方法在打印过程中应用激光涂在多层上，以在整个构建体积中形成骨料表面完整性，而不是传统的外表面修饰。该目标的核心是了解热输入（从沉积下一层材料）如何以及机械输入（来自后期的pe阶段）会影响较早的Peening步骤引起的有利的压缩应力曲线。这将通过1）量化工作硬化，细化和残留应力导致的脱位密度，2）验证镁合金强度和延性频率不同，而空间处理频率各异，以及3）验证应力腐蚀耐药性的增加。 这将导致一种新的数学模型，以预测异步打印和划分镁目标的频率以减轻先前的佩宁步骤的热和机械取消。这项奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子进行评估的值得支持的优点和更广泛的影响审查标准。

项目成果

Use of energy consumption during milling to fill a measurement gap in hybrid additive manufacturing

• DOI: 10.1016/j.addma.2021.102167
• 发表时间: 2021-10
• 期刊: Additive manufacturing
• 影响因子: 11
• 作者: K. Avegnon;P. Noll;M. Uddin;G. Madireddy;Robert E. Williams;A. Achuthan;M. Sealy

Areal surface texture and tool wear analysis from machining during powder bed fusion

粉末床熔融加工过程中的面表面纹理和刀具磨损分析

• DOI: 10.1016/j.procir.2022.03.109
• 发表时间: 2022
• 期刊: Procedia CIRP
• 作者: Avegnon, Kossi Loic;Schmitter, David C.;Meisman, Sandra;Hadidi, Haitham;Vieille, Benoit;Sealy, Michael P.
• 通讯作者: Sealy, Michael P.

Distortion mitigation in additive manufacturing of AlSi10Mg by multilayer laser peening

• DOI: 10.1016/j.procir.2020.01.179
• 发表时间: 2020
• 期刊: Procedia CIRP
• 作者: G. Madireddy;J. F. Liu;M. Sealy

Applications of Hybrid Manufacturing during COVID-19 Pandemic: Pathway to Convergent Manufacturing

COVID-19 大流行期间混合制造的应用：融合制造之路

• DOI: 10.1520/ssms20210022
• 发表时间: 2022
• 期刊: Smart and Sustainable Manufacturing Systems
• 影响因子: 1
• 作者: Bapat, Salil;Sealy, Michael P.;Rajurkar, Kamlakar P.;Houle, Tom;Sablon, Kimberly;Malshe, Ajay P.
• 通讯作者: Malshe, Ajay P.

Convergent Manufacturing: A Future of Additive, Subtractive, and Transformative Manufacturing: Proceedings of a Workshop

融合制造：增材、减材和变革制造的未来：研讨会论文集

• DOI: 10.17226/26524
• 发表时间: 2022
• 期刊: Washington D.C.
• 作者: National Academies of Sciences, Engineering