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

这个资助机会学术联络与工业（GOALI）项目将解决材料转移的基本问题，从一种金属到另一种金属在高的力和温度，称为摩擦堆焊。 这是基于摩擦搅拌焊接技术，其中旋转工具被迫进入材料，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在相对较低的温度下通过机械结合来粘附材料，从而导致高结合强度、高污染耐受性、低环境影响和低成本。 技术挑战集中在材料转移、粘附和沉积材料特性的性质上。 这是夏威夷大学和通用汽车公司之间的合作研究。 本研究确定了两个目标应用：1）汽车-传统的涂层工艺并不特别适用于钢铁和轻质材料，并且成功率有限。因此，需要一种有效且易于操作的技术来改性金属部件的表面组成以使其更耐腐蚀。2)海军-船舶中的密封件易受腐蚀，并且当前的电镀保护方法不足以将镍合金涂覆到腐蚀的、不清洁的钢船体上。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应用，作为通过材料的机械转移进行涂层/包覆的替代方法。 PI将通过位于马诺阿的夏威夷大学的夏威夷土著科学工程导师计划与夏威夷土著学生一起进行这项研究。该项目的目标是描述使用消耗性工具进行摩擦表面处理时的材料转移。 该研究将产生有关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。将表征材料被转移的工具和基底的特性。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与基底之间的粘附性质，以建立工艺参数、工艺条件、材料转移和对工作材料的粘附之间的关系。该计划是：1）通过实验测量工艺参数和条件对从自耗工具转移到刚性表面的材料的量和质量的影响; 2）建立转移材料的冶金学和粘附力; 3）对整个材料中的应力、应变和温度分布进行建模; 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。 通用汽车公司为该项目提供了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.