GOALI/Collaborative Research: Thixotropic Metal Processing and 3D Printing of Zinc-Magnesium Bio-Alloys for Biomedical Implant Applications

GOALI/合作研究：用于生物医学植入应用的锌镁生物合金的触变金属加工和 3D 打印

基本信息

批准号：
2027823
负责人：
Jack Zhou
金额：
$ 33.25万
依托单位：
Drexel University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-15 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2027823&HistoricalAwards=false
关键词：
GOALI Collaborative Research Thixotropic Metal

项目摘要

This Grant Opportunity for Academic Liaison with Industry (GOALI) award supports fundamental research to explore a novel manufacturing system that is capable of 3D printing zinc-magnesium bio-alloys. These alloys are highly desirable in implanted medical devices for their biodegradability and high strength. However, powder fusion 3D printing of these bio-alloys is very difficult to control because of vaporization and oxidization under high power laser. Not having a direct printing process for zinc-magnesium bio-alloys makes it nearly impossible to manufacture custom devices. To overcome this hurdle, a new thixotropic 3D printing methodology in which the viscosity is controlled, could allow zinc-magnesium bio-alloys to be directly printed via an extrusion process into accurate, customized 3D shapes. The new technology is expected to benefit skeletal and soft tissue fixation tools, vascular inflation stents, and bone tissue scaffolds. This would lead to improvements in orthopedic, spinal and vascular surgery by providing patient-tailored medical devices that are strong and biodegradable/absorbable in the body. The new process may also be adapted to the fabrication of aluminum-based alloys for other industrial applications. The project will be used in educational outreach activities, especially to middle/high school and underrepresented minority students, to showcase high-tech bio-fabrication, biomaterials, and their surgical engineering applications.Molten alloys have low viscosity but high surface tension, making stable 3D printing nearly impossible. It is hypothesized that a two-phase micro-slurry with a fine globular morphology can be created for zinc-magnesium bio-alloys by thixotropic processing, and this can effectively make the slurry suitable for 3D printing by extrusion. Three research tasks will be performed to test this hypothesis and establish the technical feasibility of the method: 1) Conduct basic research on alloy design, morphological formation, relation between thixotropy and printability, and relation of processing, structure and property in thixotropic extrusion and printing; 2) Study the process dynamics and develop modeling capability for thixotropic 3D printing; 3) Establish a laboratory setup for freeform fabrication of zinc-magnesium bio-alloys. Researchers will obtain fundamental understanding of the unique processing-structure-property relationships of the new thixotropic metal forming and 3D printing methods and the new zinc-magnesium bio-alloy. New scientific knowledge is particularly anticipated in the following areas: a) mechanisms of promoting thixotropy of alloys in semi-solid metal processing; b) fluid mechanics and rheology in high-stress mixing of alloys; c) fundamental relationships between thixotropy and printability in semi-solid-state deposition; and d) fundamental relationships of processing, structure and property regarding biodegradability and performance of a new zinc-magnesium bio-alloy.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.

这项与行业联络的赠款机会（Goari）奖支持了基础研究，以探索能够具有3D印刷锌量生物合金的新型制造系统。这些合金在植入的医疗设备中非常需要其生物降解性和高强度。但是，由于高功率激光器下的蒸发和氧化，这些生物合金的粉末融合3D打印很难控制。没有直接打印过程的锌生物合金工艺，因此几乎不可能制造自定义设备。为了克服这一障碍，一种控制粘度的新触变3D打印方法可以使锌 - 含量生物合金通过挤出过程直接打印成准确的，定制的3D形状。预计这项新技术将使骨骼和软组织固定工具，血管通胀支架和骨组织支架有益于骨骼和软组织固定工具。这将通过提供体内强，可生物降解/可吸收的患者量化的医疗设备，从而改善骨科，脊柱和血管手术。新工艺也可以适应用于其他工业应用的铝合金制造。该项目将用于教育外展活动，尤其是中/高中和代表性不足的少数族裔学生，以展示高科技生物制造，生物材料及其外科工程应用程序。Molten合金粘度低，但表面张力高，使稳定的3D打印几乎不可能。假设可以通过触变的处理为锌 - 镁合金创建具有细球形态的两阶段微型乳状，这可以有效地使浆液适用于通过挤出来适合3D打印。将执行三项研究任务以检验这一假设并确定该方法的技术可行性：1）对合金设计，形态形成，触变性和可打印性之间的关系以及触变挤出和印刷中的加工，结构和财产的关系进行基础研究； 2）研究过程动力学并开发触变3D打印的建模能力； 3）建立一个实验室设置，用于自由形成锌 - 镁合金的锌。研究人员将获得对新的触变金属形成和3D打印方法以及新的锌 - 含量生物合金的独特加工结构 - 陶艺关系的基本理解。在以下领域中尤其预期新的科学知识：a）在半固体金属加工中促进合金的机制； b）合金高压混合中的流体力学和流变学； c）半固定状态沉积中触变的基本关系； d）关于新的锌 - 磁金合金的生物降解性和性能的基本关系，结构和财产的基本关系。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的审查标准通过评估来通过评估来支持的。