부산대학교 도서관

The duration of SHS processes occurring in thin films or in near-surface layers of the product is several tens of milliseconds. Under these conditions, the effectiveness of monitoring the reaction of the formation of a new phase can ensured if there is a monitoring system that can build based on processing acoustic emission signals that have shown high sensitivity to transformations occurring in the surface layers of the material. However, a flexible system supplemented with a waveguide which can change its dynamic characteristics and amplitude-frequency response. Experiments have shown that using a wire with a cross-section of up to 2.5 mm 2 as flexible waveguides allows reliable control of vibroacoustic processes in a vacuum chamber at frequencies up to 40 kHz at a distance of more than 2 meters without pre-tensioning. The influence of compaction when removing a conductor of sufficient cross-section from the vacuum chamber insignificantly worsens the values of the transmission coefficients. The article discusses the work of such a system, for example, of monitoring the formation of intermetallic compounds when exposed to pulse low-energy high-current electron beam on the plate of aluminum coated with a thin film of a heat-resistant Nickel alloy. Thanks to the analysis of vibroacoustic signals, it is possible to see how the exothermic chemical reaction proceeds, when the signal character changes. The clusters of points are formed on the graphs, distinguishable in the corresponding coordinates.