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

这个学术与工业联系的机会(GOALI)项目将解决在高力和高温下从一种金属到另一种金属的材料转移的基本问题，称为摩擦堆焊。这是基于搅拌摩擦焊接技术，在该技术中，旋转工具被强制进入材料中，以同时使材料变形、加热和混合材料。对不同材料的堆焊和涂层应用的需求越来越大。该技术的主要优点是在相对较低的温度下通过机械结合的方式将材料粘合在一起，从而获得高结合强度、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上。这是夏威夷大学马诺阿分校和通用汽车公司的合作研究。这项研究已经确定了两个目标应用：1)汽车--传统的涂层工艺并不特别适用于钢和轻质材料，而且取得的成功有限。因此，需要一种高效且易于操作的技术来改变金属零件的表面成分，使其更耐腐蚀。2)海军-船舶上的密封件容易受到腐蚀，目前的电镀保护方法不适合在腐蚀、不干净的钢壳上涂覆镍合金。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，作为一种通过机械转移材料进行涂层/覆层的替代方法。PIS将通过夏威夷大学马诺亚分校的夏威夷原住民科学与工程指导计划，与夏威夷原住民学生合作进行这项研究。该项目的目标是表征摩擦表面使用消耗性工具时的材料转移。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，这对所有摩擦搅拌过程都很重要。将对被转移材料的工具和衬底的性能进行表征。将通过一系列基本的实验测量、冶金学和建模来研究转移材料和基材之间的粘合性质，以建立工艺参数、工艺条件、材料转移和与工作材料的粘合之间的关系。该计划将1)通过实验测量工艺参数和条件对从消耗性刀具到刚性表面的转移材料的数量和质量的影响2)建立转移材料的冶金和附着力3)建立工艺模型以了解整个材料的应力、应变和温度分布，以及4)量化新涂层的比较性能和特性。这是搅拌摩擦加工的一个新方向。通用汽车正在为该项目提供大量的专业知识和指导，这将增强其技术相关性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.