铜/钢爆炸焊接头界面组织及力学性能研究

为了揭示铜/钢爆炸焊接的结合机理,采用光学显微镜(OM)、扫描电子显微镜(SEM)和纳米压痕仪等对T2纯铜/Q245钢爆炸焊接头结合界面组织和微力学性能进行了分析.结果表明:T2纯铜/Q245钢爆炸复合板结合界面呈现较规则的正弦波形,界面结合良好,界面处原子发生强烈扩散,形成了过饱和铜钢固溶体;界面不同区域固溶体微力学性能不同,纳米硬度在2.02~3.08 GPa,弹性模量在129.6~172.1 GPa;由界面弹性模量分布云图可知,固溶体层连续分布在界面上,由于界面原子扩散程度不同,部分区域的固溶体层厚度很薄,在光镜下很难识别,而在波峰处固溶体则比较明显.固溶体的弹性模量均比铜基体的大,其原子键合强度强于铜基体原子,在一定程度上增强了界面的结合强度,从而使界面的结合强度高于铜基体;爆炸焊接头的拉剪试验断裂位置均位于铜侧,也证实了界面结合强度高于铜基体的强度。

Microstructure and mechanical properties of explosive welded joint of copper/steel

To reveal the bonding mechanism of explosive welding of copper/steel, the microstructure and micro mechanical properties of the interface of explosive welded joint of T2 copper/Q245 steel were analyzed by optical microscope (OM), scanning electron microscope (SEM), and nanoindentation. Results show that the bonding interface of T2 copper/Q245 steel exhibited a regular sinusoidal waveform. The interface was well bonded, and the atoms at the interface were strongly diffused to form supersaturated copper steel sosoloid. The micro mechanical properties of the sosoloid were different in different regions, the nano hardness was between 2.02 GPa and 3.08 GPa, and the elastic modulus was in the range of 129.6~172.1 GPa. According to the interfacial elastic modulus distribution nephogram, the sosoloid layer was distributed continuously on the interface. Because of the different diffusion degrees of interface atoms, part of the sosoloid layer was very thin, which was difficult to be identified by OM, and was more obvious at the crest of the wave sosoloid. The elastic modulus of the sosoloid was larger than that of the copper matrix, whose atomic bonding strength was stronger than that of the copper matrix atom, which enhanced the bonding strength of the interface to some extent, thus making the interfacial strength of the bond strength higher than that of the copper matrix. The tensile shear test fracture locations of the explosive welded joint were all located on the copper side, which also verified that the interfacial bonding strength was higher than that of the copper matrix.