The influence of aluminum on the formation of the hardening phase in magnesium alloys

Purpose. Study of the effect of alloying with aluminum on structure formation, mechanical properties and heat resistance of magnesium alloys Research methods. Methods of metallographic and micro X-ray spectral analysis. Determination of mechanical properties and heat resistance. Results. The regularities of the influence of alloying with aluminum on the formation of the hardening phase in magnesium alloys have been investigated. It is shown that an increase in the concentration of aluminum in  magnesium alloy promotes refinement of the macro- and microstructure of the metal (reduces the grain size and the distance between the second-order dendritic axes) and also increases the amount of intermetallic phase. The positive effect of aluminum additives on the mechanical properties and heat resistance of cast metal has been established. The optimal level of alloying with aluminum (about 7,7 %) hes been determined, which ensures a sufficient level of mechanical properties and heat resistence. Scientific novelty. Based on the regression analysis of the experimental data, empirical equations were obtained that describe the dependences of the size of macro- and micrograins on the concentration of aluminum in magnesium alloys. It is shown that the optimal aluminum content in the magnesium alloy in the amount of ~ 7,7 % provides the best combination of mechanical properties (a sufficiently high strength and the highest plasticity) and heat resistance Practical value. It has been established that alloying magnesium alloys with aluminum is promising for improving the structure and increasing the mechanical properties and heat resistance of cast metal. This effect makes it possible to significantly expand the field of application of magnesium alloys in mechanical engineering and improve the performance of various equipment.