镀锌薄板超声辅助GMAW熔滴过渡控制与工艺研究

There are some quality questions such as metal distortion and oxidizing in arc welding process of galvanized sheet metal because of overlarge heat inputing in weld seam. If droplet transfer model can be changed in GMAW process, welding quality of galvanized sheet metal can be improved greatly. This project aims at this question to research droplet model and control of galvanized sheet welding process. . Firstly, the project will analyze characteres of ultrasonic transmission and GMAW welding circuit, and build a hardware platform of ultrasonic assistant GMAW. Secondly, by analyzing droplet transfer character, the project will research droplet force factors and design droplet force model. And it will develop a model to simulate droplet transfer with ANSYS professional software. Then it will design appropriate welding experiment and develop image monitoring of droplet transfer. With designing relevant image process algorithm, it analyzes droplet transfer character and optimize droplet model that designed. Finally it researches welding parameters and quality control to improve welding quality of galvanized sheet by analyzing welding seam microstructrue. . The project contributes to improve welding quality and develops basic research area of GMAW.

镀锌薄板电弧焊接中由于热输入过大容易产生变形与氧化等焊接质量问题，而GMAW熔滴过渡模式的改变，能够较大提高镀锌薄板焊接质量，本项目将针对此内容开展研究。项目将分析超声波传输特点，结合GMAW焊接回路，构建基于超声辅助的GMAW硬件平台；其次，分析熔滴过渡特性，研究熔滴受力因素，设计熔滴力学模型；并采用ANSYS专业软件，进行熔滴过渡模拟；此外，设计合适的焊接实验，开展熔滴过渡监控，设计相应的图像处理算法，分析熔滴过渡特征，优化设计的熔滴模型；最后开展焊接工艺与质量控制研究，分析焊缝组织，提高镀锌薄板焊接质量。. 项目研究有助于提高镀锌薄板GMAW焊接质量，拓展GMAW方法研究范畴。

项目利用超声波辅助MIG焊接镀锌薄板的方式，构建了焊接工艺实验平台；以焊接区域信息获取为目的设计了CCD图像传感器组件，设计了焊接区域信息特征提取算法，实现了主被动视觉信息采集与处理；基于BP神经网络结合贝叶斯网络方式设计了学习算法，实现了基于图像方式的焊缝熔宽与余高提取与预测；基于ANSYS软件建立了超声辅助MIG熔滴过渡复合模型，分析了熔滴生长、分离及其物理场的影响关系，从模型上探讨了超声波对熔滴的作用机制，并通过实验验证了模型的有效性；最后，分别研究了添加外部元素Cu及石墨烯纳米片对焊缝微观组织性能的影响，利用第一性原理计算了不同条件下铜粉对焊缝组织性能影响，焊接实验表明，通过添加铜粉及石墨烯纳米片能够有效的提高焊缝质量。