Optimization of friction stir welding process for joining of aluminum to steel

铝钢连接搅拌摩擦焊工艺优化

• 批准号: RGPIN-2017-05127
• 负责人: StGeorges, Lyne
• 金额: $ 1.6万
• 依托单位: Université du Québec à Chicoutimi
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=665972
• 关键词: Optimization; friction; stir; welding; process

Background****Friction stir welding (FSW) is a solid-state welding process, which can produce high quality welds of several materials difficult to weld. Due to the low energy input used, FSW creates high strength joints with reduced distortion. Being capable of handling variations inherent to high volume production, advantages of FSW also include improved process robustness and reduced production costs. FSW has rapidly gained acceptance for the manufacturing of lightweight structures. The rising demands for improved fuel economy have driven the efforts for the development of innovative aluminum products for transportation vehicles. However, the majority of the structures used in vehicle involve steel and the employment of lightweight materials in steel structures is of great interest. The use of the combination of steel and aluminum alloys has been increasing in fabrication and many efforts to weld steel to aluminum alloy have been invested.*******Problem statement****Although the benefits of FSW to join aluminum to steel are clear, the applications of FSW to alloys with high melting temperature have been limited due to stringent demands on the tool.*The FSW tool is exposed to severe stress and high temperatures particularly for the welding of hard alloys such as steels, which promotes tool degradation. For these alloys, the commercial application of FSW is limited by the high cost and short life of FSW tools. Wear has a huge influence on tool life of FSW of steel. Therefore, it is important to identify and understand the wear mechanisms present. Tool wear is influenced by many factors, which include the composition of the tool and the workpiece material, the nature of the welding operation, the welding conditions and machine setup and the tool geometry.*******Methodology proposal and expected results****In FSW, only limited work has been done on tool wear mechanisms. The goal of the proposed project is to identify the primary wear modes of tools used to produce aluminum to steel FSW joints and to explain the mechanisms contributing to tool wear and failure. With the help of existing wear models, critical factors that influence the behavior of tool wear in FSW will be identified. This knowledge will be applied to optimize welding conditions and tool performance. The identification of dominant wear mechanisms for this type of dissimilar welding will have a significant impact on the Canadian industry, because of its potential for the automotive and other industrial sectors. For the automotive industry, replacing steel with aluminum will decrease the weight of vehicle resulting in reduced fuel consumption and greenhouse gas emissions.******

背景****搅拌摩擦焊（FSW）是一种固态焊接工艺，可以对几种难焊材料进行高质量焊接。由于使用的低能量输入，FSW产生了高强度的接头，减少了变形。由于能够处理大批量生产中固有的变化，FSW的优势还包括提高工艺稳健性和降低生产成本。FSW在制造轻量化结构方面得到了迅速的认可。对提高燃油经济性的需求不断增长，推动了运输车辆创新铝产品的开发。然而，汽车中使用的大多数结构都是钢结构，轻量化材料在钢结构中的应用引起了人们的极大兴趣。钢和铝合金的结合在制造中的使用越来越多，并且已经投入了许多努力将钢焊接到铝合金上。*******问题说明****虽然FSW将铝与钢结合的好处是显而易见的，但由于对工具的严格要求，FSW在高熔点合金中的应用受到限制。* FSW工具暴露在严重的应力和高温下，特别是在焊接硬合金（如钢）时，这会促进工具的降解。对于这些合金，FSW工具的高成本和短寿命限制了FSW的商业应用。磨损对钢的FSW刀具寿命影响很大。因此，识别和理解现有的磨损机制是很重要的。刀具磨损受多种因素的影响，包括刀具和工件材料的组成、焊接操作的性质、焊接条件和机床设置以及刀具的几何形状。*******方法建议和预期结果****在FSW中，仅对刀具磨损机制进行了有限的研究。该项目的目标是确定用于生产铝-钢FSW接头的工具的主要磨损模式，并解释导致工具磨损和失效的机制。在现有磨损模型的帮助下，将识别影响FSW刀具磨损行为的关键因素。这些知识将应用于优化焊接条件和工具性能。识别这种类型的异种焊接的主要磨损机制将对加拿大工业产生重大影响，因为它在汽车和其他工业部门具有潜力。对于汽车行业来说，用铝代替钢可以减轻汽车的重量，从而减少燃料消耗和温室气体排放。******