Laser micro/nano remelting and redistribution for surface quality improvement and functionalization

激光微/纳米重熔和再分布，用于表面质量改善和功能化

• 批准号: RGPIN-2019-05126
• 负责人: Bordatchev, Evgueni
• 金额: $ 1.95万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=681749
• 关键词: Laser; micro; nano; remelting; redistribution

Surface finish is one of the most important quality characteristics of fabricated components. It becomes even more critical with introduction of additive manufacturing (AM) technologies for producing functional parts and components with complex free-form geometries. However, current AM processes result in poor surface roughness (typically from 5 to 15 um Sa), stair-step structured surfaces, droplets, adverse residual stresses, and low dimensional precision and accuracy. Therefore, AMed components critically require finishing operation to meet required surface characteristics. Still, the manual polishing requires advanced technical skills and is performed at slow processing rates resulting in high production costs. Finishing by milling always produces scallops, ridges, and valleys and exhibits a degree of form error, waviness and surface roughness.***Laser polishing (LP) is one of the advanced manufacturing surface finishing techniques that has been recently developed and successfully employed for improving surface quality without deteriorating the overall structural form through surface smoothing by melting and redistributing a thin layer of molten material. Our team was able to achieve 72 nm Sa from original 1.2 um Sa. LP opens new avenues in cost effective manufacturing of value-added parts, components and tooling significantly reducing overall tooling cost (up to 40%) and manufacturing time (up to 30%).*** The main objective of the proposed research program is to advance further fundamental knowledge, thorough understanding, and engineering foundations of the LP technology while focusing novelty on improving surface quality of AMed parts and their surface functionalization. The emphasis will be on studies how micro/nano-scale surface features enabling new and/or enhancing existing surface functionalities can be produced by laser material remelting and redistribution. This will require understanding and development of engineering/scientific fundamentals, process planning and optimization, where thermodynamic processes in the laser-material interaction zone will be studied as a micro/nano-scale. Three research topics will be investigated: a) thermodynamic modelling and experimental verification of the micro/nano remelting and redistribution process, b) process modelling, practical implementation and experimental verification of the functional surface geometry formation, and c) process parameter optimization, system identification and process planning to achieve reproducible surfaces with desired quality/functionality.*** Undertaking this synergetic groundbreaking research will pursue new scientific and technological ideas with expected influential significance in the development of an original and strategic technology that will enhance competitive advantage of Canadian companies through the development of innovative, knowledge-based, cost-efficient advanced manufacturing technologies for fabrication of the high-value components and products.

表面光洁度是制造部件最重要的质量特性之一。随着增材制造（AM）技术的引入，生产具有复杂自由几何形状的功能零件和组件变得更加关键。然而，目前的AM工艺导致差的表面粗糙度（通常为5至15 μ m Sa）、阶梯结构化表面、液滴、不利的残余应力以及低的尺寸精度和准确度。因此，AM部件迫切需要精加工操作以满足所需的表面特性。然而，手工抛光需要先进的技术技能，并且以缓慢的处理速率进行，导致高生产成本。通过铣削进行精加工总是会产生扇形、脊和谷，并表现出一定程度的形状误差、波纹度和表面粗糙度。*激光抛光（LP）是一种先进的制造表面精加工技术，其最近被开发并成功地用于通过熔化和重新分布熔融材料的薄层而使表面平滑来改善表面质量而不劣化整体结构形式。我们的团队能够从原来的1.2 μ m Sa达到72 nm Sa。LP为高附加值零件、组件和模具的成本效益制造开辟了新的途径，显著降低了整体模具成本（高达40%）和制造时间（高达30%）。* 拟议的研究计划的主要目标是进一步推进LP技术的基础知识，深入理解和工程基础，同时将新奇集中在提高AM部件的表面质量及其表面功能化上。重点将是研究如何使新的和/或增强现有的表面功能的微/纳米尺度的表面特征可以通过激光材料重熔和再分布。这将需要理解和发展工程/科学基础，工艺规划和优化，其中激光-材料相互作用区的热力学过程将作为微/纳米尺度进行研究。将研究三个研究主题：a）微/纳米重熔和再分布过程的热力学建模和实验验证，B）功能表面几何形状形成的过程建模，实际实施和实验验证，以及c）过程参数优化，系统识别和过程规划，以实现具有所需质量/功能的可再现表面。 进行这项协同突破性的研究将追求新的科学和技术思想，在开发原创和战略技术方面具有预期的影响力，通过开发创新的，以知识为基础的，具有成本效益的先进制造技术来提高加拿大公司的竞争优势。