固态金属剪切连接组织及界面演变研究

Microstructure and interface evolution of solid metal shear bonding

组织状态及界面形成过程对固态金属剪切连接后的连接强度及性能有重要影响,采用实验研究的方法,结合理论分析实施了不同压下量、空冷和水冷Q345钢剪切连接实验。通过微观组织分析、界面结合过程探究和连接强度测定,分析了组织演变和界面形成机制,得到了剪切连接过程的组织及界面演变规律。结果表明:随压下量增加,界面晶粒细化程度提高,组织得到明显细化,界面孔洞逐渐消失,形成共有晶粒界面;晶粒细化驱动为动态再结晶,界面形成为三阶段过程;压下量为125%空冷后,晶粒尺寸由原态40μm细化到10μm左右,连接界面消失,连接强度为500.56 MPa。

The microstructure state and interface formation process have important influence on the bonding strength and the properties of solid metal shear bonding. A shear bonding test under the different press quantities for air-cooled and water-cooled Q345 steel was conducted by using the method of experiment and research, combining with theoretical analysis. Through the analysis of the microstructure, interface bonding process and the measurement of bonding strength, the evolution of microstructure and interface formation mechanism were analyzed, and the microstrueture and evolution law of the interface of the shear bonding process were obtained. The results show that with the increase of press quantity, the grain refinement degree of the interface is improved, the microstructure is obviously refined, and the interfacial pores gradually disappear, common grain interface is formed; the grain refinement is driven by the dynamic reerystallization, interface is formed with three stages ; when the press quantity reaches 125% and the steel is air-cooled, the grain size is refined from the original state 40 μm to about 10 μm, the bonding interface is disappeared, and the bonding strength reaches 500. 56 MPa.