## 5 Conclusions  
The characteristics of the gas dynamics of the airflow under the electric-arc spraying with airflow pulsations and its effect on aluminum coating oxidation behavior were evaluated. The following conclusions can be drawn:  
1. When the air flows around the obstacle (two crossed electrodes), a depression zone appears within the flow behind the obstacle, in which favorable conditions for the formation of the metal droplets are reached. 2. It was revealed that the airflow pulsation caused the change in the flow structure. Particularly, the length of the zone with reduced pressure increased, covering most of the electric arc area. Between the airflow pulses, the electrode material was melted, being in the low-pressure zone with minimal contact with oxygen, reducing molten metal oxidation. It is stated that the frequency of the airflow pulsation should match the frequency of a single metal droplet formation/detachment in order to minimize the metal oxidation. 3. With the airflow pulsation frequency rising to 65 Hz, the volume fraction of the oxide inclusions gradually decreased by 3.6 times compared to the steady airflow. With a further frequency increase to 120 Hz, the content of oxides increased, remaining still lower than that of the steady airflow. It was found that at a high frequency (more than 120 Hz), the air pulsation has almost no influence on the dynamics of an atomizing airflow and the metal oxidation. Conceptualization, I.Z., V.R. and V.C. ; writing--original draft preparation, I.Z. and V.R. ; writing--review and editing, I.Z., V.R. and V.C. ; methodology, V.R. and V.C. ; investigation, I.Z. ; validation, I.Z. ; supervision, V.C. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. Data Availability StatementData sharing is not  
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