The effect of pulsed electron beam irradiation on surface characteristics of AM60 magnesium alloy

In this study, AM60 magnesium alloy surface modification was performed by electron beam irradiation at different energy densities of 3, 5, and 8 J/cm2 and a pulse duration of 2-4 μs for RITM installation and 100 μs for SOLO installation. Then the surface characteristics were analyzed and the process parameters were optimized based on microscopic images with scanning electron microscopy. The element magnesium, the intermetallic phase of Al-Mn and Mg-Al (Mg17Al12) were observed on the microstructure of all samples. It is significant that due to oxidation, the MgO phase was observed in AM60 alloy which was removed by pulsed electron beam irradiation (PEBI). This technique generally caused the percentage of the AlMn phase to be lower than the raw sample and even at the energy level of 8 j/cm2, the AlMn phase was ignored. However, the percentage of Mg17Al12 phase increased significantly after PEBI and this phase changed from block to point mode and spread throughout the material. It was found that with PEBI the surface characteristic changes and among the three levels of 33, 5, and 8 J/cm2, 5 J/cm2 has the lowest number of cracks and the shortest crack length.