超硬铝合金搅拌摩擦焊全局动态鲁棒控制技术

Global dynamic robust control of friction stir welding of high strength aluminum alloy

关键词:  7075超硬铝|搅拌摩擦焊|焊接接头强度|全局动态鲁棒控制

Key words:  7075 superhard aluminum|friction stir welding|welding joint strength|global dynamic robust control

摘要:

针对7075超硬铝在传统熔焊过程中易出现热裂纹、气孔等焊接接头软化问题，建立基于搅拌摩擦焊接工艺参数变化与焊接接头强度间的动态鲁棒控制关系. 根据全局运动与焊接强度参数间的非线性关系，建立搅拌针运动动态鲁棒控制模型，对焊接接头的断后伸长率、抗拉强度、硬度等物理参数进行计算. 建立未来时刻焊接过程工艺参数的鲁棒动态进化优化模型，实现工艺参数实时优化控制. 根据模型进行的一系列焊接接头强度试验结果，该模型的预测结果可以满足工程需要，具有工程实用价值.

Abstract:

Aiming at the softening problem of 7075 superhard aluminium welded joints such as hot cracks and porosity holes in traditional fusion welding process, a dynamic robust control model based on the relationship between friction stir welding process parameters and welded joint strength was established. According to the non-linear relationship between global motion estimation and welding parameters, a dynamic robust control model of tool pin motion was established, and the tensile shear strength of welded joints were calculated. The physical parameters such as tensile strength and hardness were calculated. A robust dynamic evolutionary optimization model of welding process parameters was established remaining process to realize real-time optimization control of process parameters. A series of strength tests of welded joints based on the model showed that the proposed model was reasonable and could meet the needs of engineering, which have practical value in engineering.