GOALI: Characterization of Material Transfer in Friction Stir Processing With a Consumable Tool

这个学术与工业联络资助机会（GOALI）项目将解决材料在高强度和高温度下从一种金属转移到另一种金属的基本问题，称为摩擦表面。这是基于搅拌摩擦焊接技术，其中旋转的工具被迫进入材料，同时变形，加热和混合材料。对异种材料表面处理和涂层应用的需求日益增加。该技术的主要优点是材料在相对较低的温度下通过机械粘接，从而具有高粘接强度，高耐污染性，低环境影响和低成本。技术挑战集中在材料转移的性质，附着力和沉积材料的性质。这是夏威夷大学马诺阿分校和通用汽车公司的合作研究。本研究确定了两个目标应用：1)汽车-传统的涂层工艺尚未被证明特别适合钢和轻质材料，并且取得了有限的成功。因此，需要的是一种有效且易于操作的技术来修改金属部件的表面成分，使其更耐腐蚀。2)海军——船舶的密封件容易受到腐蚀，目前的电镀保护方法不足以在腐蚀的、不清洁的钢制船体上涂覆镍合金。这些行业对美国的国家安全和经济福利至关重要。这项研究还将影响再制造的应用，作为一种通过材料机械转移的涂层/包层的替代方法。pi将通过夏威夷大学马诺阿分校的夏威夷本土科学与工程指导计划与夏威夷本土学生合作进行这项研究。这个项目的目标是表征材料转移摩擦表面与消耗性工具。这项研究将产生关于材料从一个表面转移到另一个表面的参数和条件的知识，这对所有搅拌摩擦过程都是重要的。材料被转移到的工具和基材的特性将被表征。通过一系列基础实验测量、冶金和建模来研究转移材料与基体之间的粘附性质，以建立工艺参数、工艺条件、材料转移和与工作材料的粘附之间的关系。计划是1)实验测量工艺参数和条件对从消耗性工具转移到刚性表面的材料的数量和质量的影响2)建立转移材料的冶金学和附着力3)为整个材料的应力、应变和温度分布建立过程模型4)量化新涂层的比较性能和特性。这是搅拌摩擦加工的新方向。通用汽车公司为该项目提供了大量专业知识和指导，这将增强其技术相关性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Grant Opportunity for Academic Liaison with Industry (GOALI) project will address the fundamental issue of material transfer from one metal to another at high force and temperature, called friction surfacing. This is based on friction stir welding technology in which a rotating tool is forced into a material to simultaneously deform, heat, and mix material. There is an increasing need for dissimilar material surfacing and coating applications. The major advantage of this technique is material adheres by mechanical bonding at relatively low temperature, resulting in high bonding strength, high tolerance to contamination, low environmental impact, and at low cost. The technical challenge centers on the nature of material transfer, adhesion and deposited material properties. This is collaborative research between the University of Hawaii at Manoa and General Motors. Two target applications have been identified for this research 1) Automotive - Conventional coating processes have not proven particularly suitable for steel and lightweight materials and have had limited success. What is therefore needed is an efficient and easily-operated technique to modify the surface composition of metal parts to make them more corrosion resistant. 2) Naval - the seals in ships are susceptible to corrosion and the current electroplating protection method is not adequate for coating nickel alloys onto the corroded, unclean steel hull. These industries are central to American national security and economic welfare. This research will also impact remanufacturing applications as an alternative method of coating/cladding by mechanical transfer of material. The PIs will work with native Hawaiian students on this research through the Native Hawaiian Science & Engineering Mentorship Program at the University of Hawaii at Manoa.The goal of this project is to characterize material transfer in friction surfacing with a consumable tool. The research will generate knowledge about parameters and conditions for transfer of material from one surface to another, which is important for all friction stir processes. The properties of tool and substrate for which material is being transferred will be characterized. The nature of adhesion between transferred material and substrate will be studied through a series of fundamental experimental measurements, metallurgy, and modeling to establish the relationship among the process parameters, process conditions, material transfer, and adhesion to the work material. The plan is to 1) experimentally measure the effects of process parameters and conditions on amount and quality of transferred material from the consumable tool to the rigid surface 2) establish metallurgy of the transferred material and adhesion 3) model the process for knowledge about distribution of stress, strain, and temperature throughout the material and 4) quantify the comparative performance and properties of the new coatings. This is a new direction for friction stir processing. General Motors is contributing much expertise and guidance to this project, which will enhance its technical relevance.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.