Structural-Phase State and Morphology of a Composite Based on Magnesium Hydride and Nanosized Aluminum Powder Obtained by Electrical Explosion of Wires

A composite based on magnesium hydride and nanosized aluminum powder obtained by electric explosion of wires was synthesized. Mechanical synthesis was carried out in a planetary ball mill. The time and frequency of synthesis, the mass ratio of balls and composite, and the percentage of aluminum were constant, while the diameter of grinding balls was varied: 3, 6, and 10 mm. Scanning electron microscopy was used to determine the average particle size of the composite depending on the diameter of the grinding balls. It was found that with a decrease in diameter from 10 to 3 mm the average particle size decreased from 2.7 to 2.2 μm. Energy dispersion analysis showed that nanosized aluminum particles were distributed evenly over the surface of magnesium hydride. A “core–shell” structure was formed. X-ray phase analysis revealed β-magnesium hydride, magnesium, magnesium oxide, and aluminum in the composite. X-ray diffraction patterns of the samples made it possible to calculate the structural parameters of the obtained composites, including microstresses. The average microstress value varied in the range of 0.004–0.006. A hypothesis has been put forward about an inversely proportional relationship between microstress and desorption temperature.