铜/铝磁脉冲半固态辅助钎焊界面扩散过程

Interfacial diffusion process of Cu/Al magnetic pulse semisolid assisted brazing

结合分子动力学模拟和试验研究,对铜/铝管磁脉冲半固态辅助钎焊界面原子扩散过程进行了研究.结果表明,在铝侧扩散界面原子主要在界面的无序原子层中相互扩散,且各元素的扩散行为不均匀,铝基体原子向钎料的扩散速度远小于钎料原子向铝基体扩散的速度;铜侧界面在模拟设置的冲击速度下,扩散层很薄且厚度变化并不明显.测量不同冲击速度下铝侧界面的扩散层厚度发现,随着冲击速度增加,模拟的扩散层厚度呈线性增加,与试验结果相符.根据模拟与试验结果建立了在相同或相近的冲击速度下,模拟界面扩散层厚度与试验界面扩散层厚度之间的关系,模拟结果能够较好地预测试验界面扩散层厚度,最大误差为2.8%.

The atomic diffusion process of the magnetic pulse semi-solid assisted brazing interface of copper/aluminum tube was studied by molecular dynamics simulation and experiment.The results show that the atoms at the aluminum side diffusion interface mainly diffused with each other in the disordered atomic layer at the interface,and the diffusion behavior of the elements was not uniform.The diffusion speed of the aluminum matrix atoms to the filler metal was much lower than that of the filler metal atoms to the aluminum matrix.At the copper side interface,the diffusion layer is very thin(about two atomic layers thickness)and the thickness changes are not obvious at the simulated impact speeds.It is found that the simulated diffusion layer thickness increases linearly with the increase of impact speed,which is consistent with the experimental results.According to the simulation and experimental results,the relationship between the simulated interface diffusion layer thickness and the test interface diffusion layer thickness is established under the same or similar impact velocity.The simulation results can well predict the test interface diffusion layer thickness,with a maximum error rate of 2.8%.