THE INFLUENCE OF HEAT TREATMENT ON THE MICROSTRUCTURE AND PROPERTIES OF AL30 ALLOY OBTAINED BY ELECTROMAGNETIC CASTING

Abstract

The article considers the heat treatment effect on the microstructure and microhardness of AL30alloy ingots with diameters of 12 and 80 mm, obtained by casting in an electromagnetic crystallizer(EMC). A homogeneous microstructure formed by a mixture of an aluminum solid solutionand a eutectic phase was formed in the investigated ingots. It was established that the microstructuredispersion and the microhardness level of AL30 alloy ingots significantly depend on thecrystallization rate. Heat treatment of cast samples with diameters of 80 and 12 mm performedaccording to the T6 mode makes it possible to achieve microhardness values of 147±9 HV and156±3 HV, respectively. Evaluation of heat resistance showed that at the temperature of 300 °Cthe nature of the change in samples microhardness of different diameters is identical. After holdingfor 100 hours, the microhardness of AL30 alloy samples strengthened as a result of T6 heat treatmentis ~67 HV.