Fundamental Research on a Novel Double-Pulse Laser Micro Sintering Technology

新型双脉冲激光微烧结技术基础研究

基本信息

批准号：
1728481
负责人：
Benxin Wu
金额：
$ 29.97万
依托单位：
Purdue University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2022-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1728481&HistoricalAwards=false
关键词：
Fundamental Research Novel Double Pulse

项目摘要

Selective laser sintering (SLS) is an additive manufacturing process capable of rapidly and flexibly producing complex metallic parts. An SLS process, which is set up to manufacture micron sized components or components with micron scale features, can be called 'laser micro sintering' (LMS). One challenge associated with LMS is that fully dense metallic components are difficult to achieve. Through this award a novel double-pulse laser micro sintering process (DP-LMS) will be investigated. This new process has the potential to enhance the densification (reduce internal voids), and hence improve the mechanical properties of parts produced by LMS. The research focuses on understanding the material's transient responses during the DP-LMS process, and subsequently establishing the relevant process-structure-property relationships. The knowledge gained is also potentially relevant to other material processing and synthesis processes involving metal powder sintering. Successful implementation of the DP-LMS process has great potential to positively impact applications that may benefit from rapid and flexible fabrication of complex components with micron scale aspects such as MEMS, or micro medical devices. It is expected that both graduate and undergraduate students will be involved in the research, and that process principles and/or new findings will be incorporated directly into a current manufacturing classes and a video that will be made available to the public. The specific research objectives are: (1) to test the hypothesis that during DP-LMS, suitably sending the two pulses can effectively help material densification with little increase of its surface roughness; (2) fundamentally understand the heat transfer, phase change, melt flow, and densification process in the target material during DP-LMS; and (3) establish the process-structure-property relationships for the DP-LMS process. The research tasks include: (1) in-situ study of the DP-LMS process using fast pyrometry, fast imaging, and emission spectroscopy to measure target temperatures, surface morphology variations, and plasma properties. (2) Development of a continuum-mechanics based model to understand the thermal and fluid transport and phase changes in the target material during the DP-LMS process. The model will be validated by the experimental measurements in task 1. And (3), characterization of the sintered material microstructures and mechanical properties through optical and electron microscopy, X-ray diffraction and hardness testing.

选择性激光烧结（SLS）是一种增材制造工艺，能够快速、灵活地生产复杂的金属零件。 SLS 工艺用于制造微米尺寸的部件或具有微米级特征的部件，可称为“激光微烧结”(LMS)。与 LMS 相关的一项挑战是难以实现完全致密的金属部件。通过该奖项，我们将研究一种新型双脉冲激光微烧结工艺（DP-LMS）。这种新工艺有可能增强致密化（减少内部空隙），从而提高 LMS 生产的零件的机械性能。研究重点是了解材料在 DP-LMS 过程中的瞬态响应，并随后建立相关的过程-结构-性能关系。获得的知识还可能与涉及金属粉末烧结的其他材料加工和合成过程相关。 DP-LMS 工艺的成功实施具有巨大的潜力，可以对应用产生积极影响，这些应用可能受益于微米级复杂组件（例如 MEMS 或微型医疗设备）的快速灵活制造。预计研究生和本科生都将参与这项研究，并且该工艺原理和/或新发现将直接纳入当前的制造课程和向公众提供的视频中。具体研究目标是：（1）验证DP-LMS过程中，适当发送两个脉冲可以有效帮助材料致密化，而表面粗糙度几乎没有增加；（2）从根本上了解DP-LMS过程中目标材料中的传热、相变、熔体流动和致密化过程； (3)建立DP-LMS过程的过程-结构-属性关系。研究任务包括：（1）利用快速高温测量、快速成像和发射光谱对DP-LMS过程进行原位研究，以测量目标温度、表面形态变化和等离子体特性。 (2) 开发基于连续介质力学的模型，以了解 DP-LMS 过程中目标材料的热和流体传输以及相变。该模型将通过任务 1 和 (3) 中的实验测量进行验证，通过光学和电子显微镜、X 射线衍射和硬度测试表征烧结材料的微观结构和机械性能。