项目批准号：51705280
申请代码：E0508
项目名称：搅拌摩擦焊根部材料连接机理(lǐ)及性能(néng)调控方法研究
项目负责人：陈高强
依托单位：清华大學(xué)
研究期限：2018-01-01 至 2020-12-31
资助经费：27.0（万元）
项目摘要
中文(wén)摘要：
根部缺陷危害搅拌摩擦焊接头的承载能(néng)力及服役安全性，但依靠无损检测手段几乎无法检出。根部缺陷的产生根源是根部材料未发生完全连接，但搅拌摩擦焊过程中根部材料的连接机理(lǐ)尚不清楚，导致相关性能(néng)调控方法缺乏全面的理(lǐ)论支撑。本项目拟以高强铝合金為(wèi)对象，采用(yòng)计算机模拟与实验研究相结合的方法，研究搅拌摩擦焊中根部材料的连接机理(lǐ)及性能(néng)调控方法，定量表征不同焊接参数下根部材料经历的温度、应力、应变等物(wù)理(lǐ)条件，定量阐明搅拌摩擦焊过程中根部材料“从分(fēn)离到结合”的固态连接动态物(wù)理(lǐ)过程，深入揭示根部材料经历物(wù)理(lǐ)条件、材料连接行為(wèi)、根部力學(xué)性能(néng)之间的内在联系，明确控制搅拌摩擦焊接头中的根部性能(néng)的关键影响因素及其影响规律。基于对根部材料连接机理(lǐ)的准确理(lǐ)解，建立根部材料性能(néng)的调控方法，為(wèi)搅拌头设计、焊接参数优化以及接头性能(néng)调控提供指导。
英文(wén)摘要：
The ‘root flaw’ has detrimental effects on the mechanical performance and the in-service safety of the friction stir welds, but the root flaw could be hardly detected by the non-destructive tests. The formation of the root flaw is attributed to insufficient solid-state bonding between the seaming interfaces at the root region. However, the mechanism of material bonding at the root region has not been fully understood, which causes the lack of a solid theoretical basis for eliminating of the root flaw and controlling the performance of the welds. This project aims to investigate the solid-state bonding process at the root region during friction stir welding (FSW) by using both numerical simulation and experimental examination. The evolution of thermal-mechanical state variable, such as temperature, stress and plastic strain, at the root region under various welding conditions is to be quantified by experimental-validated numerical simulation, which will be used to analyze the material bonding process at the root region. The interplay between the thermal-mechanical state variables, material bonding behavior and mechanical performance is to be revealed in order to clarify the key influencing factor that governs the joint performance at root region. The processing control method for eliminating root flaws is to be established based on the material bonding mechanism and the key influencing factors, which will provide practical guides to the optimization of the welding parameters and welding tool design.
                                                                                                                                                                                                             ——来自https://kd.nsfc.gov.cn/